• Elise Deschenes (elise.deschenes@hotmail.com), Université de Montréal
• Stephanie Pellerin (stephanie.pellerin.1@umontreal.ca), Université de Montréal
• Marie-Hélène Brice (marie-helene.brice@umontreal.ca), Université de Montréal
• Monique Poulin (Monique.Poulin@fsaa.ulaval.ca), Université Laval

Species diversity typically decreases towards the poles, but this pattern does not hold for all ecosystems and plant functional groups. Studying distinct groups simultaneously (e.g., vascular and bryophytes) in ecosystems where they are abundant, such as peatlands, should provide insight on factors governing diversity and should help predict compositional changes in response to environmental variations. The objective of our study was to evaluate the influence of latitude, abiotic variables, and peatland types (bogs vs. fens) on vascular and bryophyte diversity. Inventories were conducted in 380 peatlands in northeastern Québec (49° to 54° N). We evaluated changes in alpha (species richness and functional dispersion) and beta diversity (LCBD indices) in response to latitude, continentality, climate, and local abiotic variables for both plant groups using generalized linear models. We also evaluated the effects of these variables on taxonomic and functional composition using variance partitioning by redundancy analysis (RDA). We found that bryophyte richness increased towards the north, while vascular richness showed contrasting patterns in bogs and fens in response to latitude. In fens, richness decreased towards the north, and inversely in bogs in which functional diversity remained higher. Higher latitudes were associated with taxonomic and functional homogenization for both plant groups in both habitats. Environmental variables had different effects across plant groups and type of diversity (alpha or beta). Taxonomic and functional composition of both vascular and bryophyte species were primarily structured by environmental filtering (mainly contrasting local conditions in bogs and fens). Bioclimatic variations along the latitudinal gradient seemed to play a secondary role. Therefore, both plant groups and habitats are affected differently by environmental factors, and future studies and policies should include these differences when evaluating the effects of environmental changes on biodiversity and planning conservation.

• Nicolas Perrault (nperraul@ualberta.ca), IRBV, University of Alberta
• Joan Laur (joan.laur@montreal.ca), IRBV, Université de Montréal, Jardin botanique de Montréal
• Uwe Hacke (hacke@ualberta.ca), University of Alberta

L'arsenic est un métalloïde hautement toxique, connu pour ses effets néfastes sur les organismes vivants et sa distribution étendue dans l'environnement, d'où le besoin d'étudier les techniques visant la décontamination des milieux touchés. La phytoremédiation constitue une approche écologique pour répondre à ce problème, notamment dans le contexte de sols contaminés. Certains projets de phytoremédiation passés ont cependant démontré une augmentation de la concentration de contaminants due à l'activité physiologique de saules. Ce phénomène, qui semble opposé au principe de décontamination des sols, fut initialement associé à la migration de contaminants en direction des systèmes racinaires. Cette expérience vise à déterminer si ces résultats pourraient plutôt être causés par un processus physiologique végétal appelé ascenseur hydraulique, en étudiant les mouvements de l'arsenic. Il est également bien documenté que l'eau et l'arsenic se déplacent dans les tissus végétaux par l'entremise de protéines membranaires identiques, soit différentes aquaporines. Nous voulons donc déterminer les principales aquaporines spécifiques au saule noir impliquées dans le processus d'ascenseur hydraulique de l'arsenic. Pour y arriver, des boutures de saule noir furent cultivées en serre dans des systèmes à double-pot, représentant la séparation entre les couches profondes et de surface du sol. Le seul lien entre les deux pots étant la bouture de saule, les mouvements moléculaires observés entre les pots ne pouvaient se produire que par l'entremise des systèmes racinaire et circulatoire de la plante. Nos résultats indiquent que l'arsenic peut être redistribué par les saules noirs, du sol humide au sol plus sec, de façon similaire à l'ascenseur hydraulique. Ceci explique l'augmentation de contamination en surface des sols phytoremédiés. Ces résultats soutiennent l'idée d'utiliser la culture de saules à combinée avec des hyper-accumulateurs à racines peu profondes dans le sol sec de surface comme un moyen plus efficace de décontaminer les sols sur leur profil complet.

• Xiangbo Yin (yinx01@uqat.ca), Université du Québec en Abitibi-Témiscamingue
• Abdul Samad (abdul.samad@nrcan-rncan.gc.ca ), Laurentian Forestry Centre
• Christine Martineau (christine.martineau@nrcan-rncan.gc.ca ), Laurentian Forestry Centre
• Nicole Fenton (nicole.fenton@uqat.ca), Université du Québec en Abitibi-Témiscamingue; NSERC-UQAT Industrial Chair in Northern Biodiversity in a mining context

Plant-microbe interactions contribute to biodiversity and ecological services (e.g., nitrogen and carbon cycle) in different forest biomes, including the moss phyllosphere of the boreal forest. Increases in mining activities to satisfy mineral requirements are potential threats to ecosystem services provided by microorganisms of the moss phyllosphere, not only in directly disturbed mining areas, but also in relatively intact offsite landscapes. To improve our understanding of the offsite impacts of mining on microbial communities of the phyllosphere, we sampled Pleurozium schreberi (Brid.) Mitt. (a feather moss species) within 1-km mosaic landscapes containing four forest types (i.e., coniferous, deciduous, mixed forest and open canopy peatland) around six mine sites at different stage of the mining lifecycle in the Canada?s boreal zone. Microbial DNA was recovered from the P. schreberi phyllosphere and characterized by metabarcoding of the bacterial 16S rRNA gene and fungal ITS2 region. Offsite effects of mines on the bacterial and fungal communities of the phyllopshere were detected using this approach. Mining stage and forest type both affected the alpha and beta diversity as well as the relative abundance of individual taxa from both groups of organisms, but unexpectedly their effects did not generally interact. Individual microbial taxa had higher indicator values of offsite effects than community-level diversity indices, and the strongest effects occurred within a 0.2 km distance from operating mines for most taxa. Our results suggest that predicted shifts in forest composition under global change scenarios should not interact with the offsite effects on feather moss phyllosphere in boreal forest. Furthermore, although the influenced area is small near a single mine, the total area could be substantial across the globe. Further studies will be needed to assess how these offsite effects of mining on the phyllosphere structure affect the functioning of boreal ecosystems and to develop appropriate mitigation strategies.

• Alexandre (AM) Michaud (alexandre.michaud.7@umontreal.ca), UdeM
• Michel Labrecque (michel.labrecque@umontreal.ca), UdeM
• Sébastien Boquel (Sebastien.Boquel@cerom.qc.ca), CÉROM
• Snizhana Olishevska (Snizhana.Olishevska@cerom.qc.ca), CÉROM

Les cultures de saules à croissance rapide (SCR) connaissent un certain essor au Québec, notamment pour leur utilisation en phytoremédiation et pour diverses autres applications environnementales. Plusieurs cultivars d'espèces différentes sont ainsi utilisés. Cependant, la sensibilité de certains génotypes aux insectes ravageurs ainsi que les conséquences de ces attaques sur la productivité sont moins bien documentées. Cette sensibilité pourrait varier selon les génotypes de SCR mais également selon les régions et l'âge des plants. Cette étude vise donc à étudier la communauté d'insectes ravageurs et bénéfiques présente dans les plantations de SCR afin de déterminer l'abondance, l'occurrence et la variabilité de leurs impacts. Ce projet apportera de nouvelles connaissances sur les interactions entre les communautés d'insectes et les cultivars de SCR utilisés en phytoremédiation.

• Enrique Hernández-Rodríguez (enrique.hernandezrodriguez@uqat.ca), Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue(UQAT)
• Carlos Cerrejón (carlos.cerrejonlozano@uqat.ca), Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue(UQAT)
• Xiangbo Yin (xiangbo.yin@uqat.ca), Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue(UQAT)
• Marion Noualhaguet (marion.noualhaguet@uqat.ca), Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue(UQAT)
• Marc-Frédéric Indorf (marc-frederic.indorf@uqat.ca), Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue(UQAT)
• Juan C. Villarreal (juan-carlos.villarreal-aguilar@bio.ulaval.ca), Département de Biologie, Université Laval
• Nicole Fenton (nicole.fenton@uqat.ca), Institut de Recherche sur les Forêts (IRF), Université du Québec en Abitibi-Témiscamingue(UQAT)

Identifying rare species at risk of extinction is essential for biodiversity conservation. According to the Rabinowitz rarity forms (RRF) approach, rarity is generated by a combination of characteristics related to habitat specificity, population size, and geographic range of the species. We use the Rare7 package to classify 290 bryophytes (92 liverworts, 170 mosses, and 33 sphagna) between the seven RRF. In our analysis, the habitat specificity was determined by four forest types: conifers, mixed-wood, deciduous, and open forest in the temperate and boreal region (eight habitats), considering 1064 study sites in western Quebec. The population size was defined by the number of occurrences in the study sites. The geographic range was established based on the extremes of latitude of the species distribution in the study area. Of the total species, 52 % (150 spp.) were common, while the remaining 48% (140 spp.) have forms of rarity characterized by having small or large populations in one or several habitats in a wide geographic range (RRF: 1-3). We did not identify species with restricted geographic ranges and scarce or abundant populations inhabiting only one forest type (RRF: 4-7). Mosses presented more common species (81), followed by liverworts (50) and sphagna (19). The proportions of species per RRF 1 and 3 per bryophyte guild follow the same pattern as their common species. However, we found a similar number of species with abundant populations inhabiting a single forest type (RRF: 2) for the three guilds. Our results contrast with the assumption that most bryophyte species are rare. Also, it highlights that bryophyte have wide geographical ranges which supports the premise about their long dispersal capacity. Finally, our work highlights the importance of the preservation of different forest types because they are unique habitats for species with abundant populations.

• John Markham (john.markham@umanitoba.ca), University of Manitoba
• Mauricio Fernández Otárola (mauricio.fernandez@ucr.ac.cr), Research Center for Biodiversity and Tropical Ecology, University of Costa Rica

Montane tropical ecosystems can have more nitrogen leaving them than enters them by the about 5 kg N ha-1 yr-1. Cloud forests in tropical montane regions have almost year-round high humidity and consequently support a large biomass of tree epiphytes, including cryptogams. Since cryptogams can harbor nitrogen-fixing cyanobacteria, they may help make up for the nitrogen loss from these ecosystems. We quantified nitrogen fixation, using 15N2 uptake, in cryptograms in Quercus costaricensis stands near the tree line (ca. 3300 m asl) in the Cordillera de Talamanca, Costa Rica. Total cryptogam biomass was 2 977 kg ha-1, of which 67% was on lower tree branches, 20% on boles, 12% on upper branches, and 1% on the ground. Bryophytes, chlorolichens, and cyanolichens made up 53%, 44%, and 3%, respectively, of the biomass. Rates of N2 fixation per tissue mass were highly variable with cyanolichens fixing 12, liverworts 9, mosses 5, and chlorolichens 2, µg N g-1 d-1. When adjusted for abundance, the overall nitrogen input from fixation was 6.1 kg N ha-1 yr-1, of which 50% came from liverworts, 28% from mosses 18%, from chlorolichens, and 4% from cyanolichens. Only 2.0% of the nitrogen fixation occurred on the ground, whereas 67%, 24%, and 7% occurred on the lower branches, boles, and upper branches, respectively. These results show that tree epiphytes constitute the major source of N fixation associated with cryptogams and a significant nitrogen source for these forests, due to the trees' large surface area. N fixation by tree epiphytes can also make up for the nitrogen lost from these ecosystems.

• Naziha Bendou (naziha.bendou1@uqac.ca), UQAC LASEVE doctorat en biologie
• Yacine Boumghar (yboumghar@cmaisonneuve.qc.ca), Directeur Innovation et Recherche Technologique Appliquée, Directeur CÉPROCQ et Titulaire de la chaire de recherche industrielle dans les collèges du CRSNG sur les extractibles agroforestiers.
• André Pichette (andre.pichette@uqac.ca), Directeur du Centre de recherche sur la Boréalie (CREB) et Directeur du Laboratoire d?analyse et de séparation des essences végétales (LASEVE)
• Vakhtang Mshvildadze (Vakhtang_Mshvildadze@uqac.ca), Professeur en Pharmacognosie DSF, UQAC.
• Jean Legault (jean_legault@uqac.ca), Professeur au département des sciences fondamentales UQAC.

Carthamus Caeruleus L est une plante endémique connue dans le nord algérien, notamment en Kabylie sous son nom vernaculaire « Mersgess ». C'est une espèce rencontrée en méditerranée dans les clairières humides des forêts, les plaines, les bords des ruisseaux et surtout dans les terrains argileux. Dans la médecine traditionnelle, ses racines sont largement utilisées, sous une forme semi- solide, particulièrement dans le traitement des brûlures cutanées et la cicatrisation. L'objectif de cette recherche vise l'analyse phytochimique (portions polyphénolique et terpénique) et l'évaluation biologique (activités cytotoxique, anti-inflammatoire, antibactérienne, antifongique et antioxydant) afin de mieux rationaliser les propriétés anti-brulures de cette plante. L'extrait brut, obtenu avec méthanol et un mélange méthanol/eau 70 % à reflux, a été fractionné par des extractions liquide-liquide successives avec différents solvants de polarité croissante (dichlorométhane, acétate d?éthyle et eau). Le dosage des polyphénols a été réalisé selon la méthode de Folin-Ciocalteu, et la teneur la plus élevée a obtenue pour la fraction AcOEt (18±2% g/100g). Les analyses chromatographiques (CCM et HPLC-DAD) ont montré la présence d'acides phénoliques et de flavonoïdes, surtout pour la fraction AcOEt. L'évaluation de l'activité cytotoxique sur les cellules cancéreuses a révélé que les fractions DCM et AcOEt sont cytotoxiques pour les lignes cancéreuses (A-549, DLD-1). Contrairement aux fractions DCM et AcOEt, l'extrait aqueux ne montre pas de cytotoxicité. Les fractions DCM et AcOEt ont montré une activité anti-inflammatoire significative avec une inhibition de NO de 100% à 40µg/ml et de 80% à 40µg/ml, respectivement. L'évaluation de l'activité antibactérienne a démontré que les fractions DCM et AcOEt sont actives avec des IC50 de 17±9µg/ml et 62±14µg/ml contre E.coli et de 18±4µg/ml et 85±1µg/ml contre S.aureus, respectivement.

• Christina Thibeault (christina.thibeault1@uqac.ca), Université du Québec à Chicoutimi
• André Pichette (andre_pichette@uqac.ca), Université du Québec à Chicoutimi
• Vakhtang Mshvildadze (vakhtang_mshvildadze@uqac.ca), Université du Québec à Chicoutimi
• Jean Legault (jean_legault@uqac.ca), Université du Québec à Chicoutimi

Comme le montre le contexte sanitaire actuel, il existe encore un fort besoin de découverte de nouveaux médicaments pouvant agir sur un éventail de pathologies. Dans cette perspective, il faut admettre que les plantes demeurent une source privilégiée de composés bioactifs utiles. En effet, bien qu?on estime que plus de 60 % des médicaments ont une origine végétale, il existe encore une grande proportion de plantes non étudiées ou non valorisées. À ce jour, peu d?études ont été réalisées sur le pin blanc (Pinus strobus) bien qu?il soit utilisé depuis longtemps dans la médecine amérindienne pour le traitement de la douleur, des infections et de l?inflammation. Il est donc opportun de se pencher davantage sur sa composition et ses propriétés pharmacologiques. Le but de ce projet de recherche est donc orienté vers l?étude des constituants biactifs du bois de pin blanc, la caractérisation structurale des composés purs ainsi que l?évaluation de leurs activités biologiques. Le fractionnement bioguidé de l?extrait éthanolique a permis l?obtention de six fractions enrichies en composés polyphénoliques. L?une de ces fractions montre une forte activité antifongique contre Candida albicans (IC50 = 24,8 ± 0,4 µg/ml) ainsi qu?une cytotoxicité contre des cellules cancéreuses du poumon, A-549 (IC50 = 89 ± 4 µg/ml), et du côlon, DLD-1 (IC50 = 67 ± 3 µg/ml). Un stilbène et cinq flavonoïdes ont été isolés jusqu?à maintenant dans cette fraction et leur identification a été réalisée à l?aide des données issues de la spectrométrie de masse et de la spectrométrie de résonance magnétique nucléaire. Plus précisément, la caractérisation chimique a mené à l?identification du pinosylvin monométhyl-éther, du pinocembrin, du 8-méthyl-pinocembrin, du 6-méthyl-galangin, du tectochrysin ainsi que du 3-acétyloxy-5,7-dihydroxy-6-methyl-flavanone. Le criblage phytochimique des fractions enrichies permet d?affirmer la présence d?autres polyphénols qui pourront être isolés du bois de pin blanc.

• Morgan Glofcheskie (glof7370@mylaurier.ca), Department of Biology, Wilfrid Laurier University
• Anna Ho (hoxx2540@mylaurier.ca), Department of Biology, Wilfrid Laurier University
• Mihai Costea (mcostea@wlu.ca), Department of Biology, Wilfrid Laurier University

Cuscuta (dodder) includes ca. 200 species of plant obligate stem parasites with both ecological and economical significance. Inflorescences have been historically used in Cuscuta for species descriptions and identification keys, but no comprehensive study exists to date. The main objective of this study was to survey the diversity of inflorescences and to understand their evolution and possible form-function relationships. The inflorescence architecture of 132 Cuscuta taxa was analysed using herbarium specimens and eight species were grown to study their inflorescence development. Inflorescence traits were mapped into a genus phylogeny obtained from a combined analysis of nuclear ITS and plastid trnL-F sequences. To test the hypothesis that inflorescence architecture is connected to sexual reproduction, we analyzed correlations between inflorescence traits and previously published values for pollen/ovule ratios and flower diameter. Based on their development, three major types of inflorescences were observed. “Cuscuta type” is a simple, monochasial scorpioid cyme. In “Monogynella type”, cymes are compound monochasial scorpioid, but their longest primary axes have a prolonged vegetative growth giving the appearance of thyrses. “Grammica type” consists of compound monochasial scorpiod cymes with up to 4 orders of axes. Parsimony and maximum likelihood analyses inferred Monogynella as the ancestral type, while Cuscuta and Grammica were derived. Overall, the total length of axes exhibited a reduction trend throughout the genus evolution. Further morphological inflorescences types recognized in subgenus Grammica by analogy with racemose inflorescences, “racemiform /paniculiform”, “umbelliform/ corymbiform” and “glomeruliform” exhibited convergent evolution. Low correlations values were obtained only between pedicel length and flower diameter. No relationship was observed between pedicel and total axe lengths or between inflorescence traits and pollen/ovule ratios. These results suggest that the function of the inflorescence in Cuscuta is to prolong sexual receptivity and increase sexual assurance, and that breeding systems are not influenced by the inflorescence architecture. 

• Rémi Boisvert (boir14@uqat.ca), Université du Québec en Abitibi-Témiscamingue
• Nicole Fenton (nicole.fenton@uqat.ca), Université du Québec en Abitibi-Témiscamingue

Dans le contexte des changements que subit actuellement la biosphère, des données sur la biodiversité sont essentielles pour planifier l?aménagement du territoire et la préservation des espèces. Comme de nombreux groupes d?espèces, les lichens sont menacés par la perte d?habitats, les changements climatiques et la pollution. Le développement des connaissances sur leurs patrons de distribution en forêt boréale et sur leur réponse aux conditions environnementales est primordial pour assurer leur conservation à long terme. Étant poïkilohydriques, les lichens dépendent fortement du climat, qui peut être régulé par des gradients macro-climatiques et par la structure forestière. Les caractéristiques des substrats sur lesquels ils croissent sont également reconnues pour exercer une influence importante sur leur distribution. L?objectif de ce projet est de déterminer les effets relatifs du gradient macro-climatique, de la structure forestière et des caractéristiques des substrats sur les communautés de macrolichens épiphytes, épixyliques et saxicoles des forêts mixtes de la côte nord du lac Supérieur (Ontario). Spécifiquement, les réponses de la richesse spécifique, de la composition et de la diversité fonctionnelle seront étudiées. Sur huit transects de 100 km placés perpendiculairement au lac, des prélèvements de lichens sur quatre types de substrats (épinettes, bouleaux, chicots et surfaces rocheuses) ont été effectués à différentes distances de la côte. Parallèlement, diverses données liées à la structure forestière et aux substrats ont été collectées. Le processus d?identification des lichens échantillonnés est présentement en cours. Les résultats attendus éclairciront la relation entre le climat, les substrats et les communautés de lichens et pourront servir à l?élaboration de plans de conservation à long terme de la biodiversité de lichens.

• Myriam Cloutier (myriam.cloutier.4@umontreal.ca), Université de Montréal
• Etienne Laliberté (etienne.laliberte@umontreal.ca), Université de Montréal
• Mickaël Germain (Mickael.Germain@usherbrooke.ca), Université de Sherbrooke

Combining the use of drones and remote sensing with deep learning could allow researchers to map biodiversity in large or inaccessible places. We aimed to develop a functioning deep learning model to classify temperate forest canopies at the species level using remote sensing imagery. Using multitemporal data, we would expect imagery from the fall to improve the model?s performance due to tree species taking on more distinct colours in the fall. The imagery was acquired at the Station de Biologie des Laurentides of the University of Montreal. With a drone, we took high-resolution RGB imagery over 43 hectares of temperate forest on 7 different occasions between May and October 2021. We used the images to generate orthomosaics and annotated 15 different classes on those orthomosaics in the field to minimize identification errors. We used the annotated imagery to train a Convolutional Neural Network (CNN) that could be used to classify tree crowns on new imagery. We created a baseline model with a sample of the dataset. The initial model had an overall accuracy of 64%. Certain species were more accurately identified, such as Pinus strobus Linnaeus and Acer saccharum Marshall. Surprisingly, this baseline model was able to identify a P. strobus that had not been annotated in the training data. The predictions generated indicate that the model can recognize the irregular patterns in the tree crowns, including branches that stick out from the rest of the crown. Better accuracy was achieved when increasing the tile size. This shows how important the spatial context of the forest canopy can be in the training of the CNN. These results indicate that, while the dataset and the model need refinement, there is significant potential as a tool in ecology. The next step will be improving the dataset and optimizing the model?s parameters.

• Hariharan Sendamangalam Varudaraju (hariharan@unbc.ca), University of Northern British Columbia
• Lisa Wood (lisa.wood@unbc.ca), University of Northern British Columbia

Glyphosate is a post-emergent, non-selective, broad-spectrum herbicide that is globally used in forestry and agriculture to control weeds. Earlier it was thought that glyphosate is environment-friendly and does not cause any harm to nontarget organisms present in the ecosystem due to its mechanism. The mechanism of action of glyphosate is to target the shikimic acid pathway that is present only in plants. However, due to its overuse, it has leached into groundwater and soil systems where it is posing serious threats to humans and the organisms found in aquatic, and terrestrial systems. The application of herbicide not only affects the targeted plants but also reaches the non-target plants mainly due to spray drift, wind direction, and rainfall. The sublethal concentration doesn't kill the plants however, it leads to malformation of plant parts. Plants produce hormones to combat stress conditions and melatonin is one of the stress response molecules which increases in their concentration whenever the plants are exposed to heat, cold and chemical stresses. Although melatonin increases during stress conditions application of glyphosate pose a major threat to melatonin production as the application of glyphosate disrupts the production of 5-enol-pyruvyl-shikimate-3-phosphate synthase (EPSPS), which catalyzes the sixth step in the shikimic acid pathway. In the process of blocking the enzyme, glyphosate prevents the biosynthesis of aromatic amino acids that acts as the major precursors of melatonin. My research aims to study how glyphosate affects melatonin production in wild strawberries under different combinations of temperature and light periods. Wild strawberry plants will be exposed to different environmental conditions in three growth chambers and plant morphological changes will be recorded to study the plant-glyphosate relationship and leaf samples will be collected for the melatonin-glyphosate relationship on weekly basis.

• Tamara Montoya (tamaramontoya@cmail.carleton.ca), Carleton University
• Brittany Haas (BrittanyHaas@cmail.carleton.ca), Carleton University
• Shelley Hepworth (ShelleyHepworth@Cunet.Carleton.Ca), Carleton University
• Owen Rowland (OwenRowland@Cunet.Carleton.Ca), Carleton University

Plants undergo a self-pruning mechanism called abscission to detach organs. Efforts to understand this process have been led by studies in a model plant species, Arabidopsis thaliana, in which the outer parts of the flower (sepals, petals, stamens) are shed to make way for the developing fruit. Abscission involves specialized cell layers called the abscission zone (AZ) where separation takes place. When organs detach, newly exposed cells on the plant surface become sealed against water loss and pathogen entry through the formation of a protective layer. Plants in which the protective layer develops slowly or weakly are often susceptible to disease, making the study of this layer of importance to agriculture. The protective layer in Arabidopsis plants is suggested to be a lipid-based, cell wall-associated polymer such as cutin or suberin. To determine the identity of this polymer in Arabidopsis, AZs were harvested and subjected to chemical analysis using gas chromatography with flame ionization and mass spectroscopy methods of detection. This analysis revealed a form of cutin as a primary component of the Arabidopsis protective layer. Knockout mutants in genes encoding key enzymes in the synthesis of this cutin exhibited delay in floral organ abscission and the protective layer was more permeable. These data suggest roles for cutin in organ separation and surface protection.

• Aroniaina Randriamananjara (mialintsoaaroniaina.randriamananjara@uqat.ca), UQAT
• Annie DesRochers (annie.desrochers@uqat.ca), IRF - UQAT
• Nicole Fenton (nicole.fenton@uqat.ca), UQAT
• Xavier Cavard (xavier.cavard2@uqat.ca), UQAT
• Mélanie Jean (melanie.jean@umoncton.ca), Université de Moncton

Au Québec, la plantation d'espèces exotiques à croissance rapide comme le peuplier hybride (Populus spp.) est utilisée pour l'afforestation des friches agricoles et constitue un moyen pour produire du bois. Toutefois, il n'y a pas de consensus sur l'impact des espèces exotiques en plantation sur la diversité fonctionnelle et végétale du sous-bois. Des questions se posent sur comment cette diversité peut être influencée par des plantations d'espèces exotiques mélangées (mélanges de clones ou d'espèces), par rapport à des monocultures, et comment elle se compare à des forêts naturellement régénérées ou à des plantations dans des sites forestiers. On pose l'hypothèse que (i) parce qu'elle offre une structure plus complexe, la mixité du couvert devrait augmenter la diversité du sous-bois. On s'attend à ce que (ii) la différence entre les traits fonctionnels des clones mélangés influe sur la diversité et les traits morphologiques du sous-bois comme la surface foliaire spécifique (SLA) et la teneur en matière sèche de la feuille (LDMC). On émet aussi l'hypothèse que (iii) la végétation de sous-bois diffère en termes d'espèces et de traits fonctionnels entre les plantations et les forêts naturellement régénérées. Pour comparer chaque type de peuplement, le couvert et la diversité végétale du sous-bois ont été mesurés selon des approches taxonomiques et de traits fonctionnels. La SLA et la LDMC des espèces de sous-bois et la lumière ont été aussi mesurés et les espèces de bryophytes ont été récoltées pour identification au laboratoire. On s'attend à ce que la variabilité de lumière créée par la mixité du couvert et son hétérogénéité compositionnelle offrent plus de diversité végétale que les monocultures, mais tout de même moins que dans les forêts naturellement régénérées et que les traits fonctionnels liés à la dispersion et la colonisation seront plus communs dans les plantations, spécialement dans les monocultures

• Christina AM Rossi (ross8530@mylaurier.ca), Wilfrid Laurier University/ University of Waterloo
• Christian Danve M Castroverde (dcastroverde@wlu.ca), Wilfrid Laurier University

Global climate change threatens food security worldwide as rising global temperatures worsen plant disease prevalence, resulting in increased crop losses. Previous studies in the model plant species Arabidopsis thaliana showed that elevated temperatures suppresses salicylic acid production, which is a central plant hormone mediating immune responses against pathogens and pests. These studies investigating temperature-regulated Arabidopsis immunity and disease resistance have only focused on the reference Arabidopsis accession Columbia-0 (Col-0). However, it has been well-established that there is a profound intraspecific and pangenomic variation within the >1000 accessions of A. thaliana. As the natural variation of Arabidopsis immune responses at elevated temperature has not been fully investigated, our work aims to address this critical knowledge gap.

To achieve this main objective, we have been characterizing various Arabidopsis accessions from diverse geoclimate regions. Based on preliminary bacterial disease resistance assays, we have identified several potentially temperature-resilient candidate accessions. These accessions have reduced disease symptoms and lower bacterial growth at elevated temperature compared to Col-0. In addition, these accessions exhibit similar bacterial pathogen proliferation at normal and elevated temperatures. To elucidate the molecular mechanisms controlling their temperature-resilient immunity, we are currently conducting expression analyses of key immunity-related genes and quantification of salicylic acid levels.

Our identification of these Arabidopsis accessions with potentially temperature-resilient defence responses will help uncover the fundamental molecular and genetic components underpinning temperature-sensitive plant immunity. On a broader level, our findings could aid in predicting how plants may respond to our changing climate. Overall, this research will potentially lay the mechanistic groundwork for engineering disease-resistant and climate-resilient plants, which will have broad impacts on agricultural and natural ecosystems.

• Corey William Burt (burt7030@mylaurier.ca), Wilfrid Laurier University
• Sasa Stefanovic (sasa.stefanovic@utoronto.ca), University of Toronto Mississauga
• Mihai Costea (mcostea@wlu.ca), Wilfrid Laurier University

Cuscuta section Indecorae includes both agricultural pests and plants that are of conservation concern. Past taxonomic revisions of section Indecorae used solely morphology, reproductive biology and host preference to separate taxa. However, preliminary phylogenetic analyses using molecular data inferred species and infraspecific level polyphyly of C. indecora, strongly suggesting that species limits and infraspecific variation must be reconsidered. The objective of this study is to use new phylogenetic data in combination with morphometric and ecological studies to resolve this systematic issue of apparent polyphyly in section Indecorae. Herbarium specimens from across the geographic range of all section Indecorae taxa were examined. Phylogenetic trees were generated using plastid DNA (trnLF region) and nuclear ribosomal DNA (ITS region) data. Photographs and measurements for morphometric and micromorphological analysis have been captured using light and scanning electron microscopy. Measurements were aggregated and the extent of morphological variation among taxa was analyzed using clustering and ordination algorithms. Ecological information including geographical range, host range, and habitat were obtained by examining herbarium specimens and labels. Morphometric analyses of 109 herbarium specimens revealed a clear separation of C. warneri, C. coryli and a broadly defined C. indecora. The currently accepted varieties of C. indecora: indecora, longisepala and attenuata (especially the latter two), exhibited morphological overlap. Molecular analyses recovered C. warneri as sister to the other members of Indecorae clade and indicated that C. indecora consists of two sister lineages that do not correspond to the morphological variation patterns observed. Cuscuta coryli is nested within one these two lineages of C. indecora. A total of 39 host plants have been identified for C. indecora, 32 host plants for C. coryli, and 2 host plants for C. warneri. New geographic records of C. coryli are reported from Quebec, Canada.

• Jazmen Tourangeau (jazmen.tourangeau@gmail.com), Wilfrid Laurier University
• Christopher Fleet (N/A), N/A
• Mihai Costea (mcostea@wlu.ca), Wilfried Laurier University
• N/A N/A (N/A), N/A

Cuscuta (dodder) includes obligate stem parasitic plants distributed globally in a wide array of ecosystems. Some species are agricultural pests that cause significant yield losses while others are endangered and at risk of extinction. While historically Cuscuta species were initially regarded as host-specific, subsequently the paradigm shifted towards considering them as generalists. Recent studies challenged the latter view and suggested that different Cuscuta species exhibit a diversity of host rages that may vary from specialists to generalists, but even in the latter case, different dodders exhibit a preference toward certain hosts. The objective of this study is to determine and analyse the host range diversity within C. gronovii species complex, which includes several closely related widespread species native to North America. This research parallels and complements another study that aims to solve the systematics of the group. Two approaches will be undertaken. First, herbarium species of all the taxa involved will be surveyed and their host data extracted. Based on the raw data, a host frequency index will be calculated for the family, genus and species of the hosts, and bipartite host-parasite networks will be generated. Networks will reveal both the range (or degree) of generalist/specialist strategies as well as possible host overlaps among the Cuscuta taxa. We hypothesize that closer related taxa share more of their hosts ranges. Second, a field study will be conducted for C. gronovii var. gronovii in two population from Ontario to determine the development of the host range during the lifecycle of the parasite. We hypothesize that a succession of primary and secondary hosts occurs during the lifecycle of the parasite. The results of the study will help to better understand the host-parasite relationships within the genus and its possible relationships with the invasiveness/weediness or rarity of different Cuscuta taxa.

• Lucie Barbier (barl38@uqat.ca), Institut de recherche sur les forêts, GREMA, UQAT
• Sergio Rossi (sergio_rossi@uqac.ca), Département des Sciences Fondamentales, Université du Québec à Chicoutimi ; Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences
• Etienne Boucher (boucher.etienne@uqam.ca), Geotop Research Center, Université du Québec à Montréal ; Department of Geography, Université du Québec à Montréal ; Centre d?études nordiques, Université Laval
• Fabio Gennaretti (fabio.gennaretti@uqat.ca), Institut de recherche sur les forêts, GREMA, UQAT

Les projections du bilan de carbone (C) des forêts reposent sur des modèles décrivant les processus physiologiques des arbres pour évaluer la croissance des forêts. La représentation de certains processus, dont l'allocation du C et la xylogénèse, est encore une source d'incertitude dans ces projections. L'objectif de ce projet est d'améliorer les projections du bilan C de la forêt boréale en incluant explicitement l'allocation du C et les processus de formation du bois dans la modélisation. Nous utiliserons des données de suivi de xylogénèse provenant de micro-carottes et de dendromètres sur deux gradients : latitudinal et édaphique. Le gradient latitudinal est formé de cinq peuplements d'épinettes noires suivis depuis 2002. Le gradient édaphique comprend des données de deux saisons de croissance (2021-2022) pour l'épinette noire et le pin gris sur des sols sablonneux et argileux. Un dernier ensemble de données contient des mesures de flux écosystémiques prises à partir de tours à flux dans des peuplements d'épinettes noires (2010-2015). Toutes ces données (Québec, Canada) serviront à calibrer et valider la modélisation de la dynamique intra-annuelle du C avec MAIDEN, un modèle qui simule la photosynthèse, la phénologie et l'allocation. Pour cela, des approches de fusion données-modèles seront utilisées. Un nouveau module sera créé dans MAIDEN pour modéliser le contrôle direct de l'environnement sur l'allocation du C au tronc et l'accumulation de biomasse associée. Ce projet réduira les incertitudes sur les réponses de la croissance des arbres boréaux à la variabilité météorologique. Nous quantifierons l'impact de la variabilité environnementale sur le développement cellulaire pendant la xylogénèse, ce qui aura des répercussions sur le bilan C à l'échelle du peuplement dans l'est du Canada. Le nouveau modèle pourrait également être intégré dans des modèles de surface terrestre afin d'améliorer la représentation des flux de C à l'interface forêt-atmosphère.

• Richard T. Caners (Richard.Caners@gov.ab.ca), Royal Alberta Museum & University of Alberta
• René J Belland (rbelland@ualberta.ca), University of Alberta

Many bryophytes grow in highly restricted microhabitats that are characterized by a specific microclimate. Understanding how these microclimatic conditions are influenced by regional climate may determine how a species responds to climatic extremes and climate change. We examined the capacity for microhabitats to moderate regional climate for the threatened Haller's Apple Moss (Bartramia halleriana). In North America, Haller's Apple Moss is found only in Canada, where it grows on forested, non-calcareous rock outcrops in the Rocky Mountains of Alberta (Jasper National Park) and adjacent British Columbia. We used hourly data logger readings over the growing season to examine microclimate (humidity and temperature) at multiple Haller's Apple Moss sites in Jasper National Park, AB, and Mount Robson Provincial Park, BC. At each site, we placed data loggers 1) among Haller's Apple Moss colonies on rock outcrops, 2) adjacent to colonies on rock outcrops where the species was absent, and 3) within the forest understory adjacent to colonies. We compared these measurements to paired readings from a regional meteorological station nearby. Microclimate among Haller's Apple Moss colonies was disconnected from the regional climate. Colonies experienced colder, more humid, and more stable microclimate than either the region or the other site measurement locations. Forest canopy cover at sites moderated the effects of regional climate on Haller's Apple Moss. Higher canopy cover was associated with significantly lower mean daily maximum temperature, temperature range, humidity range, and growing degree-days, and higher minimum temperature, in the understory. Climate change is forecast to bring warmer and drier conditions within the range of Haller's Apple Moss in Canada in upcoming decades. Haller's Apple Moss microhabitats have the capacity to strongly moderate some of the effects of regional climate and may potentially serve as refugia for the species under extreme climatic events and climate change.

• Megan Fass (mfass@stfx.ca), Saint Francis Xavier University
• David Garbary (dgarbary@gmail.com), Jack McLachlan Laboratory of Aquatic Plant Resources, Department of Biology, Saint Francis Xavier University

In Nova Scotia, the invasive brown seaweed Fucus serratus is becoming more widely distributed both geographically and ecologically. At several sites on the Atlantic coast this species can occupy up to 40% of the area of the intertidal zone and it can be a dominant species in shallow subtidal water. To best quantify its spatial distribution and abundance, we use unmanned aerial vehicle (UAV) surveys and a U-Net deep learning algorithm to efficiently and automatically quantify cover of Fucus serratus in these new locations. The U-Net is a deep learning algorithm developed for applications in medical imaging that can return robust results with small amounts of training data, which makes it uniquely suitable for our study. Here we summarize the methodology and give preliminary results from selected field sites. We flew a Mavic 2 Pro recreational UAV ten to twenty meters above the shore at Chebogue Point in southwestern Nova Scotia to collect high quality images at low tide. Images were used to train a U-Net algorithm to differentiate between Fucus serratus and co-occurring seaweeds, in particular Fucus vesiculosus and the economically important Ascophyllum nodosum. The final trained U-Net is expected to have applications in long-term monitoring of Fucus serratus encroachment in Nova Scotia and ongoing assessment of economically important seaweeds in Nova Scotia.

• Clémence Boivin (boic40@uqat.ca), Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue
• Nicole J. Fenton (nicole.fenton@uqat.ca), Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue
• Xavier Cavard (xavier.cavard2@uqat.ca), Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue
• Mebarek Lamara (mebarek.lamara@uqat.ca), Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue

Dans un contexte où les émissions de carbone sont deux fois supérieures à la situation préindustrielle, le Groupe d’experts Intergouvernemental sur l’Évolution du Climat tire la sonnette d’alarme, avec son 6^ème rapport. Pour séquestrer plus de carbone, il est indispensable de s’appuyer sur les cycles biogéochimiques et les puits de carbone naturels, comme la forêt boréale du Québec. Jusqu’à récemment, la séquestration du carbone a été négligée dans l’étude des pratiques sylvicoles, au profit de la diversité spécifique. 

On propose d’étudier les traits fonctionnels d’effets de la végétation de sous-bois et du microbiome du sol, en lien avec la séquestration du carbone, sur un gradient allant de l’Est à l’Ouest de la forêt boréale du Québec, suite à différents traitements sylvicoles. On mesurera également les effets de l’herbivorie sur les stocks de carbone dans le sous-bois. Le microbiome du sol sera étudié grâce à l’ADN environnemental. Des échantillons de plantes vasculaires et de bryophytes seront prélevés dans le but de quantifier leur rôle dans les cycles biogéochimiques. Enfin des pièges photographiques seront installés et les traces d’animaux seront inspectées pour évaluer l’effet de l’herbivorie dans les stocks de carbone. 

Cette étude permettra de faire le lien entre la dynamique du carbone forestier et la diversité fonctionnelle de plusieurs groupes taxonomiques, et ainsi de déterminer dans quelles conditions les pratiques d’aménagement forestier durable peuvent assurer le maintien conjoint de ces deux importants services écosystémiques. 

• Manon Carboni (manon.carboni@uqat.ca), UQAT - IRF
• Nicole Fenton (nicole.fenton@uqat.ca), IRF-UQAT
• Yves Bergeron (yves.bergeron@uqat.ca), IRF-UQAT

Le sous-bois de la forêt boréale mixte est un élément important de l'écosystème forestier. D'une part, il détient une grande partie de la biodiversité, en partie grâce aux plantes vasculaires et non vasculaires qu'il abrite. De plus, la strate de sous-bois est un indicateur relativement permanent de la sévérité des perturbations naturelles et anthropiques qui touche la forêt. Par exemple, les bryophytes sont capables de fournir des informations sur l'état de santé de l'écosystème. L'objectif est donc de comprendre les changements qui se produisent dans la strate des plantes herbacées du sous-bois après une perturbation par le feu au cours du temps. La chronoséquence étudiée s'échelonne sur plus de 200 ans après feu et montre une transition graduelle entre une forêt feuillue dominée par le tremble, à une forêt de conifères dominée par le cèdre et le sapin baumier. La succession des plantes herbacées présentes dans le sous-bois suit le même schéma que la succession du couvert arborescent, c'est-à-dire, en début de succession, on observe plus de plantes exigeantes en lumière et en éléments nutritifs. Ensuite des plantes plus tolérantes à l'ombre et moins exigeantes en nutriments prennent progressivement leurs places. Les plantes herbacées présentent une succession linéaire en fonction du temps depuis le dernier feu, mais avec des fluctuations liées aux perturbations secondaires comme la tordeuse des bourgeons de l'épinette. Nos résultats renforcent l'idée que les plantes de sous-bois sont fortement associées aux effets de la luminosité et de la litière que produit le couvert arborescent présent. Il existe donc une relation entre la strate du sous-bois et le couvert forestier. Une bonne compréhension de cette relation est importante, notamment pour l'inclure dans les plans d'aménagement écosystémique.

• Rafael Otfinowski (r.otfinowski@uwinnipeg.ca), The University of Winnipeg
• Victory Coffey (coffey-v@webmail.uwinnipeg.ca), The University of Winnipeg
• Ryan Nykvist (ryannykvist@gmail.com), The University of Winnipeg

Grasslands provide ecosystem services that can be measured by their capacity to support diverse plant and soil communities. Here, we test whether soil nematodes can be used as indicators of soil health in wet meadow rangelands and how grazing intensity affects wet meadow communities above- and below-ground. We compared the structure, composition, and diversity of plant and nematode communities in a long- term grazing experiment in Manitoba. We extracted, counted, and assigned nematode genera to feeding groups to determine how grazing affects food web structure. We also measured morphometric traits of nematodes and collected traits related to their reproductive capacity from published literature. We hypothesized that grazing will: 1) alter the structure, composition, and the trait profile of nematode communities; and 2) that the effects of grazing on nematode communities will be mediated through its effect on soil and vegetation. Grazing had a significant effect on plant communities and soils. Early season, intense grazing decreased plant diversity and increased soil compaction. Although intense grazing increased the number of weedy species, late season, intense grazing also increased plant community richness and diversity. Contrary to our predictions, neither the length, volume, and mass of nematodes, nor their metabolic and reproductive traits, were related to soil variables. In contrast, nematode traits were related to the abundance of dominant plants, which responded strongly to grazing intensity. Our results demonstrate that intense grazing reduced plant diversity, which also reduced the diversity of soil nematodes. Our results also demonstrate that the dominance of wet meadow rangelands by weedy perennial and annual plants increased the length, body diameter and the number of gonads of soil nematode communities. By exploring links between grazing and soil function, our research contributes new knowledge to understand the drivers of soil health in wet meadow rangelands and helps support their sustainable grazing.

• Toky Jeriniaina Rabearison (tokyjeriniaina.rabearison@uqat.ca), Université du Québec en Abitibi-Témiscamingue
• Vincent Poirier (vincent.poirier@uqat.ca), Université du Québec en Abitibi-Témiscamingue
• Jérôme Laganière (jerome.laganiere@nrcan-rncan.gc.ca), Ressources naturelles Canada
• Adam Gillespie (agilles@uoguelph.ca), Université de Guelph
• Annie DesRochers (annie.desrochers@uqat.ca), IRF - UQAT

Les pratiques d'aménagement alternatives qui augmentent le stockage du carbone (C) dans le sol font partie des solutions basées sur la nature pour atténuer les changements climatiques. Les arbres à croissance rapide sont une piste à considérer dans ce contexte puisqu'ils accumulent rapidement du C dans leur biomasse et pourraient transférer davantage de matière organique (MO) dans le sol. Les clones de peuplier hybride n'ont cependant pas tous le même accroissement (m3 ha-1 an-1), et la relation entre l'accroissement et le C organique du sol (COS) n'est pas connue. Cinq clones ayant différents accroissements ont été sélectionnés dans une plantation de peuplier hybride située à New Liskeard, ON, Canada. Des carottes de sol ont été prélevées sur deux distances (à 175.0 et 87.5 cm du tronc) et dans 3 horizons du sol (0-20, 20-40 et 40-60 cm de profondeur) pour en analyser les teneurs en C et en azote. Le clone le plus productif (DN2 ; 24.3 m3 ha-1 an-1) a eu un stock de COS significativement plus faible avec une moyenne  estimée à 82.86 (±4.07) Mg C ha-1 entre 0 et 60 cm de profondeur (p < 0.01). La relation entre l'accroissement et le COS n'était pas linéaire et dépendait du clone. En effet, ce sont les clones 1079 et 915005 (productivité intermédiaire) qui ont stocké le plus de COS dans les 60 premiers cm de profondeur, respectivement 95.37 (±4.07) et 95.73 (±4.07) Mg C ha-1. Le COS était également plus élevé lorsque la distance de prélèvement était localisée plus près de l'arbre. Par ailleurs, les ratios C/N du sol sont plus bas pour les clones DN2 et 747210. Ainsi, la séquestration du C dans le sol pourrait dépendre davantage de la qualité de la MO apportée que de leur productivité.

• Nickolas Francis Lake (nlake1@unb.ca), University of New Brunswick
• André Arsenault (Andre.Arsenault@nrcan-rncan.gc.ca), Natural Resources Canada, Canadian Forest Service
• Les C. Cwynar (cwynar@unb.ca), University of New Brunswick

Fire is one of the largest natural disturbance factors in the boreal forest and plays a critical role in shaping the composition and trajectory of a forest; however, on the island of Newfoundland, with its unique climate, the fire dynamics are poorly understood. Arnold's Pond, located in Terra Nova National Park, Newfoundland and Labrador, was selected to investigate how fire dynamics changed throughout the Holocene in relation to vegetation changes. I used macro-charcoal to reconstruct local fire events, and pollen to determine what vegetation was present throughout the ~11,900 cal. yr BP represented in the pond sediment core. My results show that the 271-yr mean fire return interval associated with the current vegetation type is longer than most boreal forest regions within Canada. My results also show that climate, in addition to changes in the dominant vegetation, influenced the frequency of fire events during the Holocene, rather than vegetation alone.

• Laura Hjartarson (laura.hjartarson.1@ulaval.ca), Université Laval
• Juan Carlos Villarreal Aguilar (juan-carlos.villarreal-aguilar@bio.ulaval.ca), Université Laval
• Line Rochefort (line.rochefort@fsaa.ulaval.ca), Université Laval

Resource extraction is driving economic, cultural, and environmental changes in northern Canada. Even after extraction activities have ceased, legacy impacts can persist, and restoration of extraction sites is critical in mitigating long-term impacts. In the search to find a holistic and cost-effective method of revegetation, the use of biological soil crusts (BSC) to accelerate primary succession is promising. BSC are communities that include lichen, bryophytes, and bacteria, that bind together with soil particles to form a surface crust. Taking into consideration their relevant ecological functions coupled with their ability to thrive in harsh environments, BSC are well positioned to facilitate the functional recovery of degraded ecosystems. The objectives of this project are i. to characterize the lichen and bryophyte species of BSC spontaneously establishing on borrow pits; ii. to identify the environmental factors governing the distribution of these BSC communities; iii. to characterize the bacterial communities and the presence of diazotrophic bacteria associated with BSC establishing spontaneously on abandoned mine tailings. BSC establishing on abandoned borrow pits, formerly used for road construction, were surveyed in Parc national des Grands-Jardins and along La Route du Nord. We are using 16S rDNA and nifH gene sequencing to characterize bacterial diversity and to assess the presence of diazotrophic bacterial species under bare soil and three types of BSC located on abandoned mine tailings, as well as under the bryophyte/lichen layer on rehabilitated mine tailings. Our results highlight the diversity of lichen and bryophyte species present as part of the BSC, the species associations that comprise the BSC communities, and the environmental variables shaping these communities.

• Bryar Al Jaf (bryar.aljaf@plymouth.ac.uk), University of Plymouth, UK.

Fungus is one of the most pathogen who cause disease in most of economic crops worldwide. Currently, PCR-based methods are used to diagnostics these micro-organisms beside culturing and primary methods too. Many primers have been designed for detection different groups of these pathogens based on PCR, LAMP assays, T-RFLP and real-time PCR. In this project we aim to maintain different groups of fungus in both Arabidopsis and periwinkle plants (Model plants) and continue to design more primers for all of them. Different techniques can be used to detect and quantify these pathogens. Also, inserting different genes into diseased plants or find any gene who can work against selected fungus and decrease existence of these pathogens inside affected plants. Mainly presence of these pathogens in plants causes weakness of the plants, control and keep plants from theses microorganisms is almost impossible and very difficult. Following specific gene against them within Arabidopsis plants, it can be transferred into periwinkle plants and checked if the selected gene whether working or not within periwinkle plants too. More diagnostic methods can be applied to detect fungus more accurately in diseased plants. Also, apply different techniques and chemicals to control and minimize fungi existence within infected plants.

• Colleen Robertson (robertson-c94@webmail.uwinnipeg.ca), The University of Winnipeg
• Rafael Otfinowski (r.otfinowski@uwinnipeg.ca), The University of Winnipeg
• Victory Coffey (coffey-v@webmail.uwinnipeg.ca), The University of Winnipeg

Grasslands provide critical ecosystem services such as carbon sequestration, water regulation, nutrient cycling, and biodiversity conservation. However, climate change is causing periods of increasingly frequent and prolonged drought in northern Great Plains ecosystems, changing the function of grassland communities. We present research from Riding Mountain National Park, Manitoba, to illustrate links between plant community composition, leaf traits of dominant plants, and the function of prairie grasslands. We use plant community data, collected in 1973, 2010 and 2020, to understand the long-term effects of grazing on the function and resilience of northern fescue prairies. We test whether legacies of historic grazing continue to affect the structure, composition, and diversity of grassland communities, and whether species with drought tolerant leaf traits converge in historically grazed grasslands. We also explore how nutrient and carbon cycling may be influenced by leaf traits of dominant plants, including their leaf carbon and nitrogen concentrations. Fifty years after grazing, heavily grazed prairies continued to have lower plant diversity. However, prairies with light grazing had lower spatial variation in plant composition. Community weighted means of plant traits were driven by abundant species with high values of specific leaf area (SLA) and high leaf density. Based on the trait composition of northern fescue communities, we predict that lightly grazed grasslands will be more resilient to drought because of their dominant grasses, Festuca hallii and Poa pratensis, characterized by low SLA and high leaf density. Regardless of grazing history, SLA and leaf density increased in all sampled prairies over the past 50 years, illustrating that changes in grassland composition correlate with changes in the traits of dominant plants. This study is the first to relate long-term legacies of grazing on mean community traits of northern fescue prairies and to help adapt the conservation and management of grasslands to changing climates.

• Jonathan Cazabonne (jonathan.cazabonne@uqat.ca), Groupe de Recherche en Ecologie de la MRC Abitibi
• Miguel Montoro Girona (miguel.montoro@uqat.ca), Groupe de Recherche en Ecologie de la MRC Abitibi, Institut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue.
• Annie DesRochers (annie.desrochers@uqat.ca), IRF - UQAT

Eskers are fluvioglacial geological providing many natural resources important for the economy and the population. These ecosystems, and the associated fungi, seem unique in the world and have never been investigated to date. They also remain vulnerable as they are highly sought over for wood, sand, and gravel. Our study aims to characterize the diversity, composition, and structure of soil fungal communities of esker forests, as well as evaluate their distribution across podzol horizons, from functional and taxonomic levels, and evaluate its environmental driving factors. Esker podzols represent stressed environments in terms of low nutrient and water availability. As a result, plant species require symbiotic associations with fungi to thrive in harsh edaphic conditions. Moreover, Jack pine forests found on eskers seem to harbor a different fungal diversity compared to other nearby stands on clay soil. Our hypothesis is that soil fungal communities are different across both soil horizons and types and that these vertical and horizontal differences in fungal composition are mainly driven by the magnitude of differences in soil chemistry and the presence of different tree species. Our study will be held in the Abitibi region. For the intra-soil scale, a global horizon sampling campaign will be carried out. For the inter-soil scale, soil fungi from esker and clay podzols, as well as from sites with a differential vegetation composition will be characterized using DNA metabarcoding. We expect soil fungal communities to show a relationship between soil chemistry and phytobiota on both scales. This project is the first molecular-based study to assess the unique soil fungal diversity of esker forests. It will help us better understand the key role of soil fungi in the functioning of esker forests and provide arguments toward a more fungi-focused forest management perspective.

• Deanna Holt-Schmitt (Deanna.Holt-Schmitt@uqat.ca), UQAT

Bryophytes are an important component of the boreal forest ecosystem, contributing to primary productivity, carbon and nutrient cycles, and stand succession (Greiser et al., 2021; Kumar et al., 2018; Müller et al., 2019). Research has shown that areas of high atmospheric humidity in the form of cloud cover, fog, and frequent precipitation supports rich and diverse bryophyte communities (Mills & Macdonald, 2004; Ratcliffe, 1968). The climate influence of Lake Superior spans up to 80km inland by moderating temperatures and increasing atmospheric moisture by 48% (Scott & Huff, 1996). The shores consist of variable topography, creating pockets of microclimates that increase the heterogeneity of the landscape (Ratcliffe, 1968; Wester et al., 2018). Heterogeneity is further increased within the forest ecosystem through stand age and continuity, and small scale disturbances that create permanent availability of colonizing substrates (Boudreault et al., 2018; Fenton & Bergeron, 2008; Newmaster et al., 2003). The constant availability of a variety of substrates provides colonizing opportunities for bryophytes with different functional traits, and in time, increases the species richness and diversity within a stand (Boudreault et al., 2018; Fenton & Bergeron, 2008; Newmaster et al., 2003). While climactic gradients provide a general distribution of species, including microclimate variation can contribute to a more accurate range of populations (Boudreault et al., 2018; Merinero et al., 2020). Using microclimates to identify critically diverse habitats allows for prioritization of forest management activities to better protect sensitive bryophytes from harmful anthropogenic disturbances (Boudreault et al., 2018; Newmaster et al., 2003; Tukiainen et al., 2017). This research aims to conserve bryophyte species diversity in the boreal forest by identifying species distribution through macro- and microclimate gradients around the north-east shore of Lake Superior.

• Santokh Singh (santokh.singh@botany.ubc.ca), University of British Columbia

Teaching and learning experiences in two upper-level plant physiology and development, research-intensive undergraduate laboratory courses in 2020-2022 during the COVID-19 pandemic were assessed. These courses provide an enriched educational experience to approximately 150 undergraduate biology students. A number of web-based tools and videos were developed for the online delivery of the laboratory experiments and research projects. In addition, several inquiry-driven, student-centered, open-ended research projects were developed. Students worked in groups to develop their research proposal and design their research projects in the areas of plant physiology, ecophysiology, and plant development. Students were provided the research project results generated in the laboratory by the teaching assistants. Students presented their research findings online in the form of short ?Three-Minute Thesis (3MT)? oral presentations using the Canvas course website. Students also presented their research results in the form of two research journal-style written reports. Teaching and learning experiences in these courses delivered in online, in-lab, and hybrid modes will be discussed.

• Santokh Singh (santokh.singh@botany.ubc.ca), University of British Columbia

A new micro assay experimental protocol for measuring alpha-amylase activity in plant tissues was developed. The alpha-amylase micro assay utilizes a 96-well microplate using only micro liter volumes of the various reagents. The alpha-amylase activity was determined by measuring the blue color developed by the reaction of starch with the iodine-potassium iodide reagent using a microplate reader. The effect of plant hormones, gibberellic acid (GA), and abscisic acid (ABA) on the induction of alpha-amylase activity in barley half-seeds (embryo-containing or embryo-less) was investigated using the micro assay method. The alpha-amylase activity in the embryo-containing half-seeds was much greater than in the embryo-less half-seeds of barley. GA caused the induction of alpha-amylase activity in embryo-less half seeds, whereas ABA inhibited the GA-induced induction of alpha-amylase activity. This new method will be used by undergraduate research students for their independent research projects in an upper-level Plant Physiology and Plant Development research-enriched course. The new micro assay method is more convenient, rapid, space-saving, and produces less chemical waste than the traditional alpha-amylase assays.

• Katharina Braeutigam (katharina.braeutigam@utoronto.ca), University of Toronto Mississauga
• Stefan Heinen (stefan.heinen@utoronto.ca), University of Toronto Mississauga
• Oscar Nunez (oscar.nunez@utoronto.ca), University of Toronto Mississauga

Tree seed germination is critical for the maintenance of healthy natural forests and the regeneration of disturbed sites. Successful germination is strongly influenced by environmental conditions, and this might especially be true for wind-distributed seeds with little to no endosperm at maturity. As a consequence of climate fluctuations and anthropogenic activities such as mining or certain irrigation practices, soil salinity has increased, and this has removed thousands of hectares from use for agriculture and agroforestry in Canada. At the same time, little is known about the effect of salinity on seed germination in several of the tree species native to Canada. Here, we study the effect of increased salinity on seed germination in poplars, which represent prominent trees in Canadian forests and are of economic importance. Poplar seeds were exposed to increasing concentrations of salt under controlled environmental conditions. Threshold concentration for delayed development as well as lethality were determined. We also introduce the criterion of maximum harm concentration that discriminates between germination and early seedling development through seedling damage post successful germination. Moreover, effects on biomass production were analyzed. Finally, the effects of salinity on sex of the seedling in this deciduous species were studied. The findings contribute to our mechanistic understanding of susceptibility during germination and potential use in regeneration efforts of a native deciduous tree.

• Kathleen Woodhouse (kvwoodhouse926@my.nipissingu.ca), Department of Biology and Chemistry, Nipissing University
• Jeff Dech (jeffreyd@nipissingu.ca), Department of Biology and Chemistry, Nipissing University

Several studies have indicated that the association between tree growth and increasing temperature has weakened over recent years as the climate continues to warm in northern forests, particularly in Alaska. This breakdown of the temperature signal in tree-ring series has been called the divergence problem, and its extent and causes remain unclear. We examined growth in three different species of the boreal forest of northeastern Ontario over the period of 1922-2010, specifically focusing on the relationship between radial growth and temperature. Our objective was to determine if divergence is occurring in these forests, and if it is influenced by soil moisture conditions. An archive of increment core samples collected near Timmins, Ontario, was accessed to examine the growth of Picea mariana, Pinus banksiana and Populus tremuloides across a soil moisture gradient, based on measured soil moisture regimes in sample plots. Cores were collected from co-dominant trees, mounted, sanded, and crossdated following standard procedures. Tree ring widths were measured using the WinDendro software package. Crossdating was confirmed using the program COFECHA. For each dated series, regional curve standardization was used to detrend tree-ring measurements and compute master chronologies for each species and moisture regime. Correlation of tree-ring index values to annual climate data revealed that April mean maximum daily temperature was the best indicator of annual growth over the entire time period. We used running correlation analyses to determine the variability in the strength of the association between the TRI values of the various chronologies and the April mean maximum daily temperature over the time period using a 10-year analysis window. Changes in the strength of correlation were interpreted with the objective of testing the hypothesis that populations on drier sites would exhibit a stronger divergence from the temperature trend than those on mesic sites.

• Laura Super (leslaura@gmail.com), University of British Columbia
• Clara Barnes (claraubarnes@gmail.com), University of British Columbia
• Yipeng Chen (YipengChen2017@Outlook.com), University of British Columbia
• Robert Guy (rob.guy@ubc.ca), University of British Columbia

Humans are greatly impacting our ecosystems, including factors affecting each plant, its environment, and associated organisms, i.e. the phytobiome. Phytobiomes will not be in isolation, however, and it is important to understand how plants in different vegetation communities and soils will respond. In this study we ask: how are plants (tree seedling performance, neighborhood vegetation) and shoot, root, soil microbiome impacted by experimental treatments (warming, nitrogen, harvesting) and related to soil properties? Focusing here on plant response, we hypothesized that: i) planted tree seedlings (conifer phytobiomes) will have increased performance in clear-cuts compared to forest edges, ii) in clear-cuts planted tree seedlings with higher vegetation cover will be smaller because of competition, iii) more fertile soils will result in larger plants, iv) warming and nitrogen will increase plant performance, and v) there will be complex interaction effects. We performed a field experiment that had 12 plots (6 clear-cuts, 6 forest edges), with 25 subplots (or consortia) per plot randomized with simulated nitrogen deposition (none, 10 kg per ha per year) and/or simulated warming (none, passive open top chamber). Each subplot had three planted conifers (Douglas-fir, western red cedar, western hemlock), with performance measures (height, biomass or estimated biomass, etc.), soil properties (pH, organic matter content, etc.), and vegetation (cover, etc.). Preliminary data suggest that warming and nitrogen impacts are context and species dependent. Soil data are currently being analyzed in relation to the plants (conifer performance, neighborhood vegetation) as well as the experimental treatments. Microbiome data are forthcoming.

• Ines Diamant (ines.diamant1@uqac.ca), Université du Québec à Chicoutimi
• Maxence Martin (maxence.martin@uqac.ca), Université du Québec à Chicoutimi
• Junior A. Tremblay (junior.tremblay@nrcan-rncan.gc.ca), Environment and Climate Change Canada
• Hubert Morin (hubert.morin@uqac.ca), Université du Québec à Chicoutimi
• Jacques Ibarzabal (jacques.ibarzabal@uqac.ca), Université du Québec à Chicoutimi

Old-growth forests are often represented as a homogeneous group, when in fact they are very diverse in terms of tree structure and tree composition. This heterogeneity that characterizes old-growth forests offers many specific habitats that can benefit many different bird species. However, in recent decades, forest management has contributed to the rejuvenation, homogenization and fragmentation of boreal landscapes. The loss of specific structures or attributes of old-growth boreal forests, such as coarse woody debris or habitat trees, can have negative consequences on forest species that depend on them. Therefore, the goal of this project is to understand how structural attributes of old-growth boreal forests and their combinations affect bird assemblages. Our first objective is to determine the composition of bird communities as a function of different structural attributes of old-growth forests. The second objective is to determine if different bird communities are observed between different stages of forest succession. Fieldwork was conducted at the Monts-Valin National Park situated in the Saguenay region (Quebec, Canada). We sampled 40 plots – 20 in "early" old-growth forests (burned 90 years ago) and 20 in "late" old-growth forests (unburned for at least 130 years) – in which structural attributes, including tree-related microhabitats and coarse woody debris, were inventoried. Bioacoustic recorders have been installed in each plot, from which bird species and abundances will be identified. We expect to observe different bird assemblages depending on the presence of specific structural attributes (snags, tree-related microhabitat diversity) partially dependent on successional stage, here in combination with environmental conditions and the impact of recent secondary disturbances. The results of this project might help orienting ecosystem-based management towards more effective conservation and restauration efforts.

• Chloé Pelletier (pelc46@uqat.ca), UQAT
• Shawerim Coocoo (-), -
• Benoit Éthier (benoit.ethier@uqat.ca), UQAT
• Hugo Asselin (hugo.asselin@uqat.ca), IRF - UQAT

Dans le cadre de ma maîtrise à l'École d'études autochtones de l'Université du Québec en Abitibi-Témiscamingue en collaboration avec le Conseil de la Nation Atikamekw (CNA) et le Conseil des Atikamekw de Wemotaci (CAW), cette étude s'inscrit dans les démarches de mise en valeur des savoirs écologiques et culturels autochtones du CNA. Les systèmes de transmission et d'acquisition des savoirs autochtones en contexte atikamekw nehirowisiw ont été documentés à la base structurelle des relations familiales au territoire. Ce projet explore comment l'utilisation des bleuets (de la cueillette à la consommation, en passant par la transformation) contribue à l'affirmation identitaire individuelle et collective nehirowisiw ainsi qu'à la construction ou à la solidification de liens sociaux et familiaux. Minic (les bleuets, fruits) est reconnu comme une ressource socioéconomique importante, et s'avère être une ressource culturelle clé pour plusieurs Premières Nations au Québec. Après un séjour de 2 mois dans la communauté (été 2021) accompagnée de Shawerim Coocoo, nous avons pu recueillir des données qualitatives sur la valeur culturelle des bleuets au sein de la communauté de Wemotaci et sur le rôle que prennent les femmes dans la transmission des savoirs et pratiques qui y sont liés. Dans une démarche de décolonisation des pratiques de recherche occidentale, la compréhension des relations autochtones au territoire, à son aménagement et à l'utilisation de ses ressources est au coeur de ce projet, situant minic à l'intersection entre tradition et commercialisation. Selon une approche interdisciplinaire, je viserai à détailler la pluralité et l'interconnectivité des valeurs qu'a ce petit fruit au sein de la communauté.

• Marie Frissard (marie.frissard1@uqac.ca), Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi
• André Pichette (Andre_Pichette@uqac.ca), Directeur du Centre de recherche sur la Boréalie (CREB) Directeur du Laboratoire d’analyse et de séparation des essences végétales (LASEVE) Département des sciences fondamentales, UQAC
• Jean Legault (jean_legault@uqac.ca), Laboratoire de bio-activité (LASEVE) Département des sciences fondamentales, UQAC
• Vakhtang Mshvildadze (vakhtang_mshvildadze@uqac.ca), Professeur en Pharmacognosie Département des siences fondamentales, UQAC

L’étude de produits naturels bioactifs issus de plantes souvent utilisées en médecine traditionnelle est encore aujourd’hui une voie privilégiée pour la découverte de nouveaux médicaments. Ainsi quatre plantes de la forêt boréale utilisées par les Premières Nations pour leurs propriétés antibactériennes ont été sélectionnées pour ce projet. Il s’agit du Cornus sericea L., la Monarda didyma, le Rhododendron groenlandicum et le Rhus typhina. À la suite d’un criblage chimique et d’une activité antibactérienne marquée, le Rhus typhytina a été retenu pour la suite de ce projet. L’objectif de ce travail est d’identifier le ou les composés responsables de l’activité antibactérienne en procédant à un fractionnement guidé par l’activité. L’extrait méthanolique a d’abord été séparé par partition entre l’eau et l’acétate d’éthyle. La fraction acétate d’éthyle étant la plus active a été soumise à une série de purifications chromatographiques bioguidée jusqu’à isolation des composés purs. Ces composés ont été analysés par chromatographie liquide haute performance couplée à la spectrométrie de masse (HPLC MS) ainsi que par différentes expériences en résonance magnétique nucléaire (RMN 1D et 2D) afin de déterminer leur structure chimique. À chaque étape du projet, des suivis par tests biologiques (antibactérien, cytotoxique et antioxydant) ont été effectués.

Les composés identifiés appartiennent aux familles des tannins, des flavonoïdes, des coumarines, des acides phénoliques et des triterpènes. Des fractions enrichies en tannins de Rhus typhina ont montrés une activité antibactérienne contre Escherichia coli (IC₅₀ < 20 µg/mL) et Staphylococcus aureus (IC₅₀ <50 µg/mL). Une fraction enrichie en acides phénoliques et en coumarines a également montré potentiel antibactérien significatif contre Escherichia coli (IC₅₀ < 10 µg/mL) et Staphylococcus aureus (IC₅₀ < 35 µg/mL). Plusieurs fractions enrichies en polyphénols montrent une activité antioxydante sur WS-1 et ORAC proches de ceux du contrôle (quercétine).

• Éléonor (EB) Bergeron-de Pani (eleonor.bergeron-de-pani.1@ulaval.ca), GRET - Université Laval
• Line Rochefort (line.rochefort@fsaa.ulaval.ca), GRET - Université Laval
• Mélina Guêné-Nanchen (melina.guene-nanchen.1@ulaval.ca), GRET - Université Laval

Les tourbières stockent jusqu'à 40% du carbone total du sol. Leur rôle de puits de carbone est principalement causé par leur taux de décomposition beaucoup plus faible que leur taux de production. Ainsi, le carbone stocké dans les plantes par la photosynthèse est plus important que le carbone émis vers l'atmosphère par la décomposition. Cette décomposition plus lente en tourbière a longtemps été expliquée par la faible disponibilité de l'oxygène dans le sol des tourbières qui minimise la décomposition aérobique. Cependant, un nouveau mécanisme appelé « enzymic latch » ou « verrou enzymatique » propose que ce soit également l'accumulation des composés polyphénoliques qui inhiberait l'activité des enzymes et la croissance des microorganismes en sol tourbeux. L'objectif de ce projet de recherche consiste alors à faire une sélection de produits ayant un contenu élevé en polyphénols, qui sont facilement accessibles au Québec et qui sont des résidus industriels. Ces produits pourraient potentiellement être utilisés comme outil de géo-ingénierie afin de diminuer la décomposition en tourbière. Cette sélection s'appuie sur une revue de littérature ainsi que des analyses chimiques du contenu en phénol en laboratoire. Parmi les produits testés, l'écorce de bois et les feuilles de fraisier se sont avérées être de bons candidats. Ces produits sont intéressants notamment en raison de leur contenu en polyphénol élevé et ils sont des produits résiduels facilement accessibles au Québec. Ensuite, le biocharbon s'est démarqué en raison de son rôle important dans la captation du carbone et pourrait être une source de polyphénols à long terme selon la nature de la biomasse utilisée pour sa fabrication. Enfin, l'application de ces produits en tourbières pourrait éventuellement améliorer le rendement de la culture de sphaigne ou contribuer à l'augmentation de la captation de carbone pour lutter contre les changements climatiques.

• Océane Fogliani (oceanelouise.fogliani@uqat.ca), Étudiante de maîtrise d'écologie, UQAT
• Yves Bergeron (yves.bergeron@uqat.ca), IRF, UQAT
• Christine Martineau (christine.martineau@nrcan-rncan.gc.ca), Centre de foresterie des Laurentides
• Mebarek Lamara (mebarek.lamara@uqat.ca), IRF, UQAT

Le peuplier faux-tremble (Populus tremuloïdes) est l'espèce à croissance rapide la plus largement répandue dans la forêt boréale mixte de l'Est canadien. La capacité de cette espèce d'envahir les milieux perturbés est liée à sa capacité de se reproduire facilement par drageonnement. Ce phénomène par lequel des individus génétiquement identiques apparaissent de manière clonale pourrait conduire à une diminution de la diversité génotypique (clonale) dans les peuplements et, par conséquent, à une diminution de la résilience aux changements climatiques. Le peuplier faux-tremble a non seulement un intérêt écologique important, mais aussi un intérêt socio-économique pour les nombreux services écosystémiques rendus et pour lesquels il est valorisé. Ces services écosystémiques du peuplier sont influencés par plusieurs facteurs dont les micro-organismes qui lui sont associés. La composition chimique des feuilles de peupliers pourrait varier selon le génotype et sa litière pourrait donc influencer la composition des communautés microbiennes des sols. L'objectif principal du projet est de déterminer l'influence du génotype du peuplier faux-tremble sur la structure et la composition des communautés végétales du sous-bois et sur le microbiome des racines et du sol. Cette étude vise à 1) déterminer l'influence du génotype sur la chimie des feuilles, 2) caractériser la composition du sous-bois et 3) analyser la composition, la diversité et l'abondance des communautés microbiennes de l'endosphère racinaire et du sol rhizosphérique. La technique du métabarcoding (séquençage à haut débit des amplicons) sera utilisée pour étudier les communautés bactériennes et fongiques des différents types d'échantillons. Cette étude sera réalisée sur 10 clones de peupliers faux-tremble situés à la forêt d'enseignement et de recherche du Lac Duparquet.

• Tous les participants (ABC-CBA2022@uqat.ca), UQAT

Si vous ne connaissez pas l'endroit où vous devez installer votre affiche, n'hésitez pas à venir nous voir à l'accueil - If you don't know where you need to put up your poster, don't hesitate to come and see us at the front desk.

• Sarah Ishak (ishs3601@usherbrooke.ca), Université de Sherbrooke
• Isabelle Laforest-Lapointe (isabelle.laforest-lapointe@usherbrooke.ca), Université de Sherbrooke
• Sébastien Roy (sebastien.roy@usherbrooke.ca), Université de Sherbrooke

Interactions between mosses and their associated microbiomes contribute substantially to boreal ecosystem processes. While moss-cyanobacteria interactions are very well studied, mosses harbour an array of microbial species that facilitate nitrogen cycling, as well as organic matter decomposition, carbon storage, nutrient acquisition and phosphorus cycling. Current research indicates that variables such as temperature, moisture, shade, leaf-litter presence and host moss species impact moss microbiome communities. Previous studies also allude to moss microbiome differences between the photosynthetically active green zones and decaying brown zones of mosses. Unfortunately, these compartment variables have not yet been fully explored in microbiome research. Current investigations of the moss microbiome tend to only focus on taxonomic diversity, via amplicon sequencing, with microbiome functions being inferred. Hence, the specific metabolic pathways and functional genes of the moss microbiome remain unknown or poorly described. The objective of the current project was to investigate the functional diversity of 7 boreal non-feathermoss/peatmoss species from the Eeyou Istchee region of Quebec and 3 boreal feathermoss species from Alaska via shotgun sequencing (data: Dr Hannah Holland-Moritz). Eeyou Istchee moss samples were also separated into green and brown zones to further investigate interspatial functional differences. This project uses the latest metagenomic processing infrastructure and pipelines to update existing reference databases obtained from the Alaskan moss microbiome. Knowledge of the functions of the moss microbiome can provide insight into the role of moss-associated microorganisms in driving ecosystem functions such as productivity, carbon sinks, nitrogen fixation, and resilience to global change.

• Marie-Anne Viau (marie-anne.viau.1@umontreal.ca), IRBV, laboratoire Michel Labrecque
• Michel Labrecque (michel.labrecque@umontreal.ca), IRBV, Laboratoire Michel Labrecque
• Adrian Laurent Dominique Paul (adrian.paul@umontreal.ca), IRBV, Laboratoire Michel Labrecque

La pollution par les métaux traces constitue une préoccupation majeure en raison des risques de toxicité qu?elle représente pour la faune, la flore et l?environnement en général. D?après le répertoire des terrains contaminés du MDDELCC, le Grand Montréal compte plus de 11?000 sites pollués. Une approche pour l?assainissement de ces terrains est la phytoremédiation, une stratégie qui utilise des plantes pour réduire les concentrations des contaminants in situ. Cependant, une contrainte associée à la végétalisation des sites contaminés est le risque de bioaccumulation dans la chaîne alimentaire. Une solution serait l?utilisation de polycultures tirant profit de la combinaison d?espèces végétales aux caractéristiques différentes. Dans ce contexte, l?objectif principal de cette étude était de comparer l?accumulation d?éléments traces d?une plante alimentaire (Solanum lycopersicum-tomate cerise) et de plantes «?phytorémédiatrices?» (Salix discolor-Saule discolor, Achillea millefolium-achillée millefeuille, Trifolium repens-trèfle blanc) lorsque cultivées en compagnonnage sur des sols contaminés. Quinze traitements étaient examinés : cinq assemblages de plantes (tomate cerise seule, tomate cerise/achillée millefeuille, tomate cerise/trèfle blanc/achillée millefeuille, tomate cerise/saule discolor et tomate cerise/saule discolor/trèfle blanc), ainsi que trois sols (technosol à 110 mg Cu kg-1, technosol dopé à 500 mg Cu kg-1 et un sol de jardin non contaminé). Le compagnonnage avec du trèfle a grandement amélioré les rendements des autres plantes associées (c.-à-d. nombre de fruit et taille des plantes). Cependant, les analyses ont révélé que les compagnonnages étudiés n?ont pas permis de réduire suffisamment les concentrations de Cu dans les fruits pour être sécuritaire à la consommation selon la FDA (4,52 mg Cu kg-1 technosol dopé). Un projet similaire devrait vérifier l?interaction des polycultures dans un plus grand espace (c.-à-d. plein sol), avec une méthode intercalaire et examiner ainsi la compétition interspécifique lorsque les plantes ont accès aux réserves d?eau souterraine.

• Mélanie Jean (melanie.jean@umoncton.ca), Université de Moncton

Bryophytes play key roles in ecosystems in terms of regulating soil microclimate and in carbon and nitrogen (N) cycles. Associations between bryophytes and N-fixing bacteria are a significant source of N in boreal forests and may also be important in temperate ecosystems. However, the extent to which these processes are applicable to the boreal-temperate ecotone, which includes a mosaic of deciduous, mixed, and coniferous forests, remains unknown. It is increasingly recognized that these associations are widespread across species and that the focus on a few very common species limits our understanding of this process at the community level. The objective of this project was to characterize the presence of cyanobacteria and the rate of nitrogen fixation on bryophyte species found in red spruce (Picea rubens)-dominated forests in Fundy National Park (FNP; New Brunswick). In 2021, we opportunistically harvested samples from two liverwort and eleven moss species from two sites (71 bryophyte samples) and measured environmental covariates (e.g., canopy composition, soil pH). Samples were brought back to the lab and used for measurements of nitrogen fixation, isotopic composition and cyanobacterial abundance. N-fixation was measured directly by incubating 10-20 stems from each sample for 24h in a growth chamber (20°C, 18h light-6hours dark) in syringes filled with 10 ml of air and 10 ml of 98% 15N2 gas. These incubated stems plus 10-20 stems used for estimates of the natural abundance of 15N were then dried (72h at 60°C), ground, and analyzed on an elemental analyzer coupled to a mass spectrometer to obtain isotopic ratios. Cyanobacteria abundance was measured by phycocyanin extraction and spectrofluorometry analysis on 10 stems from each sample. This combined approach will allow for a first assessment of the role of the bryosphere in the Wabanaki-Acadian forest and will help to identify target species for subsequent studies.

• Béatrice Gervais-Bergeron (beatrice.gervais-bergeron@umontreal.ca), Université de Montréal, IRBV
• Michel Labrecque (michel.labrecque@umontreal.ca), Institut de recherche en biologie végétale (IRBV)
• Pierre-Luc Chagnon (pierre-luc.chagnong@umontreal.ca), Université de Montréal, IRBV

Face aux milliers de sites contaminés et abandonnés au Canada, la phytoremédiation constitue une solution prometteuse, économique et écologique qui permet de décontaminer les sols à l'aide de plantes. Toutefois, la prédictibilité de la phytoremédiation demeure limitée, en partie, dû au manque de connaissances sur les traits des plantes et les pratiques de gestion (p.ex., recépage des plantations) favorisant la décontamination. Un meilleur ancrage en écophysiologie végétale pourrait améliorer la sélection des plantes et leur succès en phytoremédiation. Pour ce faire, les traits fonctionnels (morphologiques et physiologiques) des plantes doivent être corrélés aux services de phytoremédiation. C'est pourquoi ces corrélations traits-services ont été étudiées chez les saules, un genre diversifié et polyvalent (Salix sp.) couramment utilisé en phytoremédiation.
Dans une expérience de 4 ans sur une friche industrielle contaminé, nous avons étudié l'influence de la diversité et du recépage de plantations de saules sur leurs services de décontamination. Nous avons déterminé quels traits végétaux étaient positivement associés à une décontamination (p.ex., stabilisation et extractions d'éléments traces métalliques (ETM)). Ni la diversité ni le recépage des saules n'ont eu d'impact significatif sur la décontamination. Cette dernière était plutôt expliquée par les traits des saules associés à l'économie et l'allocation des ressources végétales. L'accumulation d'ETM dans la biomasse (p.ex., phytoextraction) était davantage corrélée à une stratégie conservatrice le long du spectre économique végétal. Des investissements souterrains plus importants favorisaient également la bioconcentration d'ETM et la décontamination des sols. De plus, ces corrélations ne variaient pas selon la nature de l'ETM, suggérant qu'elles sont généralisables chez les ETM, et non pas contexte-dépendantes.
Dans l'ensemble, l'étude fournit des résultats prometteurs démontrant que les traits végétaux peuvent prédire la décontamination d'ETM. Cette approche pourrait améliorer la sélection des végétaux en phytoremédiation, et plus largement chez d'autres phytotechnologies.

• Sophie Tattrie (sp490888@dal.ca), Dalhousie University
• Arunikaa Gunawardena (arunika.gunawardena@dal.ca), Dalhousie University
• Adam Runions (arunions@ucalgary.ca), University of Calgary

The lace plant (Aponogeton madagascariensis) is an aquatic monocot that forms regular perforations throughout the leaf blade via programmed cell death (PCD). These holes result from the active destruction of specific cells (PCD cells) and the survival of others (non-PCD or NPCD cells). Several key regulators of lace plant PCD have been identified, including anthocyanin (a potent antioxidant), reactive oxygen species (ROS), and the growth hormone auxin. As PCD cell specification involves spatial patterning driven by cell-level feedbacks, unravelling the exact roles and interactions of key regulators during PCD is challenging. At present, many hypothetical scenarios seem equally likely. Computational models are useful in determining whether a proposed mechanism can plausibly produce an observed phenomenon. Our research aims to establish predictive models of PCD in lace plant that can help identify how PCD is regulated to precisely coordinate cell death. To explore potential mechanisms which may specify PCD vs NPCD cell fate we developed preliminary interaction networks accounting for anthocyanin, ROS, and auxin in COPASI. These networks were then incorporated into spatial cell-level models implemented using coupled Ordinary Differential Equations in Python. Our study involves concurrent iterations of modelling and experimentation allowing for iterative refinement of hypotheses. The location and polarization of PINFORMED1 proteins could further reveal auxin's behaviour in lace plant. For this reason, immunolocalization of PIN1 in lace plant is underway. Integrating experimental results into models informs hypothetical interaction networks accounting for relationships between key regulators. This research promises to provide insights into how key regulators interact to precisely coordinate cell death, enabled by the novel investigation of PIN1 in lace plant. In addition, our work has potential significance for understanding PCD in other developmental contexts, as well as in medical research attempting to halt/induce PCD in certain scenarios.

• Natalie Vuong (nhvuong@uwaterloo.ca), University of Waterloo
• Fabio Gennaretti (fabio.gennaretti@uqat.ca), Université du Québec en Abitibi-Témiscamingue
• Julie Messier (julie.messier@uwaterloo.ca), University of Waterloo
• Nicole Fenton (nicole.fenton@uqat.ca), Université du Québec en Abitibi-Témiscamingue

Found on trees across many biomes, epiphytic bryophytes and lichens contribute considerably to biodiversity and ecosystem processes, and act as bioindicators. Factors influencing epiphytic diversity are scale-dependent with current literature highlighting tree age and size, host specificity, and bark properties as important drivers at the tree scale. However, little is known about the association between epiphytic communities and the physiological and morphological traits of the host tree. As community assembly theory predicts that the environment of a community may affect its diversity, our study asks whether tree ecophysiology influences epiphytic bryophyte and lichen richness and abundance. We characterized the ecophysiological and morphological traits of 20 black spruce (Picea mariana) individuals from a boreal forest stand through stem water potential, maximum photosynthetic capacity, foliage density, and live crown ratio. Age, diameter at breast height, and basal area increment were included as covariates. We surveyed each tree at the branch and trunk level for epiphytic coverage and richness. Principal component analysis and linear regressions revealed that older, larger trees possessed lower foliage density which were associated with an increase in both epiphytic richness and coverage on the branches, and a decrease in coverage along the trunk . We interpret that these changes in the community with tree age may be driven by the development of unfavourable trunk habitat conditions while branches become more suitable for epiphytes with the loss of needles. The fact that our findings are in line with larger scale studies may suggest that a simple multiscale relationship exists: older eroded trees at the local scale may be driving high richness and abundance within older stands and landscapes. These links between tree traits and epiphyte communities may help predictive landscape-level models and biodiversity conservation efforts.

• Maxence Soubeyrand (maxence.soubeyrand@uqat.ca), Université du Québec en Abitibi Témiscamingue
• Philippe Marchand (philippe.marchand@uqat.ca), Université du Québec en Abitibi Témiscamingue
• Fabio Gennaretti (fabio.gennaretti@uqat.ca), Université du Québec en Abitibi Témiscamingue
• Anthony Taylor (anthony.taylor@unb.ca), Université du Nouveau Brunswick
• Loïc d'Orangeville (loic.dorangeville@unb.ca), Université du Nouveau Brunswick
• Olivier Blarquez (olivier.blarquez@umontreal.ca), Université de Montréal
• Yves Bergeron (yves.bergeron@uqat.ca), Université du Québec en Abitibi Témiscamingue

Avec les changements climatiques, les optimums climatiques se déplacent vers le nord plus rapidement que le processus de migration des arbres, ainsi on observe un décalage entre la distribution des espèces et leurs enveloppes bioclimatiques. Couplées avec l'aménagement forestier, ces perturbations pourraient profondément impacter les écosystèmes boréaux en modifiant la composition en espèce de ces forêts via la migration des espèces de feuillus tempérés vers la forêt boréale. Notre projet a pour but d'utiliser un modèle de simulation pour déterminer le potentiel d'établissement de trois feuillus tempérés (érable à sucre, érable rouge et bouleau jaune) dans des peuplements typiques de la sapinière à bouleau blanc (SBB) et de quantifier les conséquences de ces établissements sur la composition en espèce de ces peuplements. Nous avons utilisé le modèle SORTIE qui est un modèle individu centré à l'échelle du peuplement, spatialement explicite, et basé sur la croissance des individus, leur régénération et leur mortalité. Nous avons modélisé la dynamique forestière de peuplements de la SBB à différents stades de succession en rajoutant des semis d'érable à sucre, d'érable rouge et de bouleau jaune à différentes densités dans des peuplements perturbés par une coupe totale ou non perturbés. Les trois espèces de feuillus tempérés seraient capables de s'établir dans la SBB bien que le bouleau jaune ait une meilleure capacité d'intégration, et cela au détriment des espèces de conifères qui subissent une baisse de leur surface terrière. Ainsi l'établissement d'espèces de feuillus tempérés dans la SBB pourrait participer au processus d'enfeuillement dans la SBB déjà observé avec le peuplier faux-tremble et le bouleau blanc et avoir un impact à long terme sur l'aménagement forestier futur.

• Nils Ambec (nils.ambec@uqat.ca), UQAT IRF
• Nicole Fenton (nicole.fenton@uqat.ca), UQAT IRF
• Yves Bergeron (yves.bergeron@uqat.ca), UQAT IRF

Rare habitats result from the geochemistry, history, or topography of the environment. Rare habitats shelter rare species at the landscape scale (unique/few mentions in studied area) and both rare species and habitats are threatened by global changes and human activities. In Abitibi, western Quebec, the dominant habitats, forests on the clay plains and peatlands, are well studied but little is known about rare habitats, here hills top with rocky habitats (wet dripping cliffs or dry outcrops) and old-growth forests. Today's highest Abitibian hills were emerged from the proglacial lake Ojibway (10200 BP) and therefore colonised 2000 years before the surrounding landscape. The objectives of this study are to determine if the former island effect still drives plant assemblages in comparison to formerly submerged hills. In this study, vascular plants and bryophytes were sampled for all habitats. Hourly temperatures and relative humidity for a year were sampled on the top and bottom of studied hills. It is believed that plant diversity will be higher on (1) former islands than formerly submerged hills, (2) forests and wet rocks than dry rocks and (3) that their earlier colonisation is the explanation. Results validate hypotheses (1) and (2), although bryophyte species on former islands were more diverse and exclusive and the opposite was found for vascular plants. We rejected hypothesis (3) since climate and topography are likely factors for the observed differences. Indeed, contrasts of temperatures and relative humidity exist between higher formerly emerged and lower submerged hills, a difference which has not been demonstrated before. Rare habitats really do house rare species, likely because of topography in this case. Former islands palaeoecological studies are needed to assess these results and see if post glacial communities were already bryophyte rich, maybe with today?s rarest species.

• Jeff Dech (jeffreyd@nipissingu.ca), Department of Biology and Chemistry, Nipissing University
• Tegan McWhirter (tegan.klmcwhirter@gmail.com), Department of Biology and Chemistry, Nipissing University
• Elizabeth Elliott (lizanneelliott01@gmail.com), Department of Biology and Chemistry, Nipissing University
• Elizabeth Webb (ewebb5@uwo.ca), Department of Earth Sciences, Western University

Charcoal is a biological legacy material that contains an isotopic record of fire characteristics. In a pair of field studies examining the oxygen isotope (?18O) composition of charred tree bark, we examined the potential to separate fires of differing severity, and to measure variation in severity within a single fire event. In both studies, a randomized sampling design was executed to collect charred bark samples from residual stems of the dominant tree species at each study site. The ?18O value of each bark sample was determined at the Laboratory for Stable Isotope Science at Western University. In the first study, we measured a significant difference in the oxygen isotope values we collected from a moderate-intensity prescribed surface fire ignited near North Bay, Ontario, compared to a high-intensity crown fire that burned in Hearst, Ontario, and an extreme-intensity crown fire that burned in Temagami, Ontario. These differences emerged once the data were standardized to eliminate species and location effects by determining the difference between the ? 18O value of each char sample and the mean ?18O of uncharred bark of that species at each location (?18Obark-char). In the second study, we determined that the ?18O values of samples of charred bark collected from residual white pine (Pinus strobus) in a network of plots across a single large crown fire near River Valley, Ontario, were significantly related to standard estimates of fire severity derived from remote sensing data (normalized burn ratio) or field assessment (composite burn index). Based on these relationships, we were able to predict classes of fire severity for sample plots with moderate success, typically within one category of the field-based classification. Collectively, these results suggest that this approach holds some promise for differentiating and reconstructing the severity of past fire events from charred bark materials.

• Maísa De Noronha (Maisa.DeNoronha@uqat.ca), Doctorante, Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC J9X 4E5, Canada.
• Rock Ouimet (rock.ouimet@mffp.gouv.qc.ca), Chercheur, Direction de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs, Québec, QC, G3E 2C9, Canada.
• Martin Barrette (martin.barrette@mffp.gouv.qc.ca), Chercheur, Direction de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs, Québec, QC, G3E 2C9, Canada.
• Alain Leduc (leduc.alain@uqam.ca), Professeur, Co-directeur, Institut de recherche sur les forêts, Département des sciences biologiques, Université du Québec à Montréal, Centre-Ville, Montréal, QC H3C 3P8, Canada.
• Yves Bergeron (yves.bergeron@uqat.ca), Professeur, Institut de recherche sur les forêts, Département des sciences biologiques, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC J9X 4E5, Canada.

Interactions between tree species play an important role in the forest's productive dynamics. Notably, the survival and growth of seedlings of economically relevant species may be limited by soil composition. The fall of leaves from trees and/or needles on the ground forms plant litter, which in turn is decomposed and incorporated into the soil, which determines the physicochemical and biological properties of the humus: the litter nourishes the humus and the humus nourishes the plant. Deciduous stands are characterized by generally drained soils and high availability of nutrients in the humic layer. In contrast, spruce-moss stands are characterized by often poorly drained soils and acidic humic layer. As a corollary, presence of these two species in different degrees of mixture in the stands can be beneficial to spruce seedlings productivity. In this context, it was hypothesized that leaf litter and humus from pure spruces-moss stands, pure deciduous stands, and mixed stands (e.g., Black spruce and Trembling aspen) may influence spruce seedling productivity and development differently. A greenhouse experiment was carried out to evaluate the effect of different leaf litter and different humus on the spruce seedlings growth. Our results suggest better development and better vital appearance for plants grown in humus from mixed stands (50% B. spruce / 50% T. aspen) and pure T. aspen stands compared to humus from pure B. spruce or standardized forest nursery soils. Furthermore, leaf litter from deciduous trees, such as Alders, T. aspen, Willows and Paper Birch, has shown promising results in the growth and development of B. spruce plants in greenhouse. Therefore, the promotion of forest diversity can increase its productivity by improving the physicochemical composition of the forest floor.

• Étienne Léveillé-Bourret (etienne.leveille-bourret@umontreal.ca), Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Québec, Canada
• Julian Starr (Julian.Starr@uottawa.ca), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
• Quinn Eggertson (quinn.eggertson@agr.gc.ca), Biodiversity and Bioresources, Agriculture and Agri?Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada
• Sarah Hambleton (sarah.hambleton@agr.gc.ca), Biodiversity and Bioresources, Agriculture and Agri?Food Canada, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada

Since the beginning of the 20th century, scientists have noticed that the parasites of closely related hosts tend to be more similar to each other than the parasites of distantly related hosts. One explanation for this pattern is that divergence between populations of one host causes divergence of their associated parasites, a phenomenon called ?cospeciation?. In the absence of other evolutionary processes such as host shift and extinction, cospeciation should result in parasite phylogenies that perfectly mirror host phylogenies. In the past, this motivated mycologists to propose that patterns of infection by fungi could aid plant classification. More recently, a large body of literature has suggested that cospeciation is in fact the exception rather than the rule in nature. Using examples from the rust (Pucciniaceae) and smut fungi (Ustilaginomycetes) of sedges (Cyperaceae), we will show how (1) mistaken ideas about host relationships, (2) misconceptions about evolutionary trends in parasites, and (3) morphological convergence confounded early attempts to use fungal parasites as a tool for sedge classification. Nonetheless, we will present one fascinating counter-example where high congruence is observed between the phylogenies of rusts and of their sedge hosts, and describe modern uses of fungal infection patterns in sedge taxonomy. Finally, we will call attention to the promise of DNA barcoding and of collaborations between botanists and mycologists for bridging knowledge gaps in poorly studied plant-associated fungi.

• Juan Carlos Villarreal A. (jcvil9@ulaval.ca), Université Laval
• Marta Alonso-García (marta.alonso-garcia.1@ulaval.ca), Université Laval
• Raquel Pino Bodas (rpino@bio.ucm.es), Royal Botanic Garden, Kew

Lichens are one of the main structural components of plant communities in the North American boreal biome. They play a pivotal role in lichen woodlands, a large ecosystem situated north of the closed-crown forest zone, and south of the forest?tundra zone. To explore genetic diversity in the proposed national lichen, Cladonia stellaris, we genotyped 122 individuals collected across a latitudinal gradient in Quebec. Using a population genomic approach for the main fungus, we discovered that populations in southern Quebec are not genetically different from those of northern LWs. The mycobiont consists of at least four phylogenetic lineages with elevated levels of genetic diversity and low co-ancestry suggesting either recurrent dispersal or cryptic sexual reproduction. Additionally, phylogenomic analyses of the algal partner revealed genetic congruence between the mycobiont and algae strongly suggesting co-dispersion. Genetic diversity of each symbiont was the factor explaining most of the genetic variation of the other symbiont, whereas geography or climatic region have little explanatory power.

• Étienne Lacroix-Carignan (etienne.lacroix-carignan@hotmail.com), Institut de Recherche en Biologie Végétale and Département de Sciences Biologiques, Université de Montréal, Montréal, Quebec, Canada.
• Julian R. Starr (julian.starr@uottawa.ca), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
• Robert F. C. Naczi (rnaczi@nybg.org), New York Botanical Garden, Bronx, New York, USA.
• Étienne Léveillé-Bourret (etienne.leveille-bourret@umontreal.ca), Institut de Recherche en Biologie Végétale and Département de Sciences Biologiques, Université de Montréal, Montréal, Quebec, Canada.

Increasing access to genomic methods improves our ability to parse morphological variation into coherent and strongly supported taxonomic units, and has revolutionized the way we look at hybridization in plants. Carex subsect. Lupulinae (Cyperaceae) is a well-defined clade of four showy sedge species common in forested wetlands of eastern North America that has been the subject of no less than four independent taxonomic revisions in the last 50 years. All these treatments agree over the delimitation of taxa, but there are still some hidden corners in our understanding of this group. A thorough search of herbarium collections has unearthed a century-old problem involving many odd specimens thought to be of hybrid origin. Although the existence of hybrids within subsection Lupulinae or with the closely related section Vesicariae is still debated, a large number of hybrids have been recognized by at least some authors, mainly in the early 20th century. None of these putative hybrids have been verified cytologically or genetically, and there remains doubt as to whether they exist and persist in nature. Their true parentage will be tested for the first time using phylogenomic tools and a broad sampling of co-occurring species in mixed populations. Some sedge hybrids are fertile and it cannot be excluded that introgression (i.e. hybridization followed by backcrosses to one parent) occurs within the subsection. Gene flow between the very common Carex lupulina and Carex lupuliformis, a closely related and rare sympatric species, will be assessed using phylogenomic tools and these results will help inform conservation strategies.

• Étienne Lacroix-Carignan (etienne.lacroix-carignan@umontreal.ca), Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Québec, Canada.
• Denis Paquette (denpaq_ca@videotron.ca), Independant researcher, Prévost, Québec, Canada.
• Geoffrey Hall (geoffrey.hall@umontreal.ca), Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Québec, Canada.
• Étienne Laliberté (etienne.laliberte@umontreal.ca), Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Québec, Canada.
• Étienne Léveillé-Bourret (etienne.leveille-bourret@umontreal.ca), Institut de Recherche en Biologie Végétale (IRBV), Département de Sciences Biologiques, Université de Montréal, Québec, Canada.

Once a dominant feature of rural landscapes, hawthorn (Crataegus) thickets are now threatened by urban sprawl, changes in agricultural practices and invasion by exotic buckthorn (Rhamnus cathartica). Despite their importance as food and shelter for a wide variety of organisms, very little attention is given to hawthorns and their habitat by conservationists. This situation is due in large part to the important difficulties faced by botanists brave enough to attempt their identification. In addition to the subtlety of taxonomic criteria and the need to study flowering and fruiting specimens, the widespread occurrence of apomixis in the genus has led to a proliferation of minor morphological variants, and to many conflicting taxonomic treatments. This is particularly problematic in the province of Québec, where the number of recognized species vary from 16 to 45 according to different authors. As a first step towards an updated treatment of the genus in Québec, the authors started a large collecting campaign that resulted in many floristically-important discoveries. Populations of Crataegus coccinoides, previously thought to be rare, appear locally abundant around Lake Champlain. Crataegus canadensis, a narrow endemic restricted to south shore of the St. Lawrence near Montréal, was found to be highly morphologically and phenologically distinct from the common and widespread Crataegus submollis, with which it is often synonymized. We also report results of a preliminary investigation into the use of leaf spectroscopy to assist with the identification of hawthorns. Despite the fact that few taxa are sufficiently rare in Québec to warrant legal protection, the quality and size of hawthorn habitat appears to be shrinking in the southern portion of the province. Additional studies would be needed to determine whether conservation efforts are required to reverse this trend.

• Simon Morvan (simon.morvan@umontreal.ca), Institut de Recherche en Biologie Végétale de l'Université de Montréal
• Maxime C. Paré (maxime_pare@uqac.ca), Université du Québec à Chicoutimi
• Anne Schmitt (anne.schmitt1@uqac.ca), Université du Québec à Chicoutimi
• Jean Lafond (jean.lafond@agr.gc.ca), Agriculture et Agroalimentaire Canada
• Mohamed Hijri (mohamed.hijri@umontreal.ca), Institut de Recherche en Biologie Végétale de l'Université de Montréal

La communauté microbienne du sol est essentielle pour que les bleuetiers prospèrent dans leur environnement acide et pauvre en nutriments. Cependant, les producteurs prennent rarement en compte les impacts des pratiques agricoles sur le microbiome. La fauche thermique est l'une de ces pratiques, mise en œuvre pour stimuler la production de bleuet sauvages et pour lutter contre les indésirables. Cet effet est particulièrement intéressant pour les producteurs biologiques qui ont des options phytosanitaires limitées. Cependant, l'intensité du feu nécessaire pour observer ces bénéfices reste floue et son impact sur le microbiote est inconnu.

Pour évaluer si cette pratique devrait être adoptée, nous avons mesuré l'effet du brûlage sur la chimie du sol, la communauté microbienne du sol, les indésirables, ainsi que sur la performance agronomique. Trois intensités de feu ont été testées dans une bleuetière de recherche au Québec. Des carottes de sol ont été prélevées pour l'analyse chimique, et le rendement des bleuets ainsi que le recouvrement des mauvaises herbes et des maladies ont été mesurés tout au long de la saison de croissance. Des échantillons de sol rhizosphérique ont été prélevés afin d'extraire l'ADN pour l'analyse des communautés microbiennes.

Avec l'intensité de feu la plus élevée, nous avons observé une augmentation significative mais temporaire du phosphore du sol ainsi qu'une réduction temporaire des symptômes de la maladie Septoria sp. Cependant, nous n'avons enregistré aucun effet sur le rendement, ni de changement significatif, que ce soit pour les bactéries ou les champignons. Les champignons mycorhiziens éricoïdes prédominent tandis que d'abondants taxons bactériens ayant une capacité de dégradation du carbone et un potentiel de fixation de l'azote ont été trouvés. Dans l'ensemble, ces résultats indiquent que la fauche thermique n'est peut-être pas une alternative aux pesticides en raison de son manque d'efficacité, bien qu'elle préserve le microbiome.

• Maxime (M) Thomas (maxime.thomas@uqat.ca), UQAT-IRF
• Hugo Asselin (hugo.asselin@uqat.ca), UQAT-École d'études autochtones?
• Mebarek Lamara (mebarek.lamara@uqat.ca), UQAT-IRF
• Nicole Fenton (nicole.fenton@uqat.ca), UQAT-IRF

The boreal forest is one of the most vulnerable ecosystems to climate warming. In Canada, this ecosystem is also subject to industrial disturbances, such as logging, mining, or hydroelectricity production and transport. These disturbances can interact with climate warming, and result in cumulative impacts, whose effects are greater than the sum of the individual disturbances. Indigenous communities are closely connected to the boreal forest, and cumulative impacts could affect them greatly. For example, changes in abundance, distribution or chemical composition of cultural keystone species could hinder the practice of traditional and subsistence activities. Rhododendron groenlandicum is a cultural keystone species for several Indigenous communities in boreal Canada, including Mistissini, Nemaska and Abitibiwinni. The leaves of this species are used in traditional medicine to treat a variety of ailments such as headache or diabetes. To assess the impact of disturbances on the medicinal properties of R. groenlandicum, 90 leaf samples were collected in 18 plots: 6 near mining sites, 6 under hydroelectric power lines and 6 in control plots far from industrial disturbances. The concentration in total polyphenolics and several flavonoids in the samples was analyzed in relation to disturbance type and community. We found that samples from Nemaska, the northernmost community with the most open forest stands, had higher concentrations of total polyphenolics and most of the flavonoids. Concentrations of some flavonoids were also slightly higher under hydroelectric power lines, whereas concentrations of other flavonoids were slightly lower near mining sites. These variations in concentrations could be related to canopy openness (supported by a correlation analysis = -0.47), in combination with other environmental factors. These factors could thus be of importance in determining R. groenlandicum medicinal properties. Our study provides a mean to assess the vulnerability of Indigenous ways of life to the cumulative impacts of anthropogenic and climatic disturbances.

• Christina AM Rossi (ross8530@mylaurier.ca), Wilfrid Laurier University/ University of Waterloo
• Julie Messier (julie.messier@uwaterloo.ca), University of Waterloo

Accurately quantifying tree growth is important for ecology and forestry to assess individual and population growth and timber yield. To measure growth, basal area increment (BAI) is typically calculated from tree rings measured on cores. Current methods for estimating BAI from radii assume trees are perfect circles with a centered pith, but trees often exhibit pith offset (pith eccentricity) and stem out-of-roundness (stem eccentricity). We do not know how eccentricity leads to estimation error. Our study addresses this gap by quantifying the effects of eccentricity on BAI estimation and considering whether area calculation method and number of cores can rectify this error.

We examined 109 tree sapling cross-sections from 25 different tree species varying in pith and stem eccentricity. On each cross-section, we calculated BAI using one to four cores and using four area calculation methods. Results show that eccentricity does create BAI estimation error. Pith eccentricity explains 28% of the variance in estimation error whereas stem eccentricity explains 9% of the variance. These effects can be reduced by taking more cores, as for both eccentricity types percent error decreases as more cores are taken. In fact, taking four cores completely accounts for eccentricity. Adding a second opposite core leads to the largest decreases in error: for pith eccentricity, the average percent error decreases by half from one core to two opposite cores. Further, the four area calculation methods preformed similarly.

From our analyses we recommend quantifying eccentricity in ones samples and estimating BAI from multiple cores to account for error introduced by eccentricity. Given logistical limitations we recommend, taking a second core opposite to the first, which will meet both of these objectives.

• Nicole Kathryn Botten (botten@unbc.ca), University of Northern British Columbia
• Lisa June Wood (Lisa.Wood@unbc.ca), University of Northern British Columbia
• Art Fredeen (Art.Fredeen@unbc.ca), University of Northern British Columbia
• Jeffery Ross Werner (Jeffery.Werner@gov.bc.ca), British Columbia Ministry of FLNRORD

Highly effective, nonselective glyphosate-based herbicides (GBHs) are used in the forestry industry to remove vegetation competing with commercially important conifers during reforestation. Although glyphosate may be stored in tissues of plants that received a sublethal dose of GBH, prior to our study glyphosate persistence in forest ecosystems had not been monitored beyond one year. Our primary objective was to determine the duration (up to twelve years) of glyphosate persistence in roots, shoots, and fruits of perennial plants in GBH-treated forest cutblocks. Since glyphosate can form insoluble complexes with metal ions, our second objective was to determine if concentrations of six metal nutrients were significantly altered by GBH treatment. Samples from five species growing in two biogeoclimatic zones of northern British Columbia were analyzed for glyphosate content, and comparisons were made between species, plant tissue type, and zone. Shoot samples from three species in one zone were further analyzed for nutrient concentrations. Glyphosate was detected in all plant tissues for a minimum of one year after treatment, and at least six years in shoots and 12 years in roots of some species. Samples from the drier, colder zone retained significantly higher residue concentrations for longer than samples from the warmer zone. Nutrient concentrations were more variable over time in treated samples than in control samples, and comparison of treated and control samples resulted in significant differences in 47 % of cases. Generally, Ca, Mg and Ni decreased, Zn increased, and Fe and Mn had inconsistent changes with treatment. Both the persistence of glyphosate and related changes in plant nutrients may have cumulative health effects that should be considered when assessing exposure of wildlife and humans to chronic, low concentrations of glyphosate and other chemicals in the environment, particularly in northern ecosystems.

• David Garbary (dgarbary@gmail.com), St. Francis Xavier University
• Nicholas Hill (fernhillns@gmail.com), St. Francis Xavier University
• Elena Ponomarenko (ecosystemarchaeology@gmail.com), Ecosystem Archaeology Services, Ottawa

In the context of regional climate change, we evaluated the frequency and intensity of storm winds at 15 sites from four provinces in Atlantic Canada. Monthly values for maximum wind gust speed and number of days with wind gusts > 75 km h-1 were extracted from weather station data on the Government of Canada website: https://climate.weather.gc.ca/historical_data/search_historic_data_e.html. The following metrics were determined for each site on a yearly basis: (1) mean of monthly maxima, (2) maximum annual wind gust, (3) number of days per month with gusts > 75 km h-1, and (4) number of months per year with gusts >75 km h-1. Results are considered in the context of regional climate change since 1960 in which mean annual temperature has increased about 0.9°C. Patterns of decrease and increase in both temperature and wind had consistent directional trends. A pattern emerged in 13 of the 15 sites (all but southwestern Newfoundland) in which the earlier period (i.e., the 1960s) had greater maximum wind velocities and a greater number of storm days per year. This was typically followed by a decades-long period of declining wind metrics and relative stability, with fewer and less intense storms. A recent period of increasing values for wind metrics started around 2000; however, values were typically below those from the 1960s. These results are discussed in the context of their impact on marine and terrestrial plant communities.

• Liette Vasseur (lvasseur@brocku.ca), Brock University
• Mohamed Lahbib ben Kalifa (hb19et@brocku.ca), Brock University
• Heather VanVolkenburg (hvanvolkenburg@brocku.ca), Brock University

Cover crops are increasingly popular in vineyards. While for many years grape growers used rye (Lolium perenne) as the major cover crop, with a changing climate and in order to increase biodiversity in their perennial agroecosystems, there is an interest to select new species that can tolerate various climatic conditions. Flooding due to heavy rainfall and droughts are becoming more frequent in Canada and are known to affect grape performance and berry quality. In this study, we examined the responses of nine cover crops species (six legume and three grass species) under three soil moisture conditions to determine which species may potentially be used in field vineyard conditions. These conditions were (1) saturation, watered at 100% field capacity daily, (2) control, watered at 60-70% every other day, and (3) drought, watered at 15-20% weekly. The experiment was conducted in Brock?s greenhouse and plants were grown in these conditions for 53 days. Fresh and dry weights of roots and shoots were recorded. The results showed that under drought conditions, all species had significantly lower weight than under the control conditions. Most species, except Thinopyrum intermedium and Festuca rubra, exhibited stress symptoms. Under saturation conditions, the individual root and shot weights of all species, except Medicago sativa, were either greater or not significantly different than the control. Trifolim incarnatum and Vicia villosa showed slight yellowing of foliage under saturated conditions. When performances under both saturated and drought conditions were compared to the control, pearl millet (Cenchrus americanus) followed by yellow clover (Melilotus officinalis) and wheatgrass (Thinopyrum intermedium) had the smaller differences suggesting that these species may be able to tolerate such a range of conditions. The results from this study provided preliminary information for selecting and then testing these species in the field.

• Jonathan Kusa Kimbukusu (jonathan.kimbukusukusa@uqat.ca), Université du Québec en Abitibi-Temiscamingue (UQAT)
• Annie Desrochers (annie.desrochers@uqat.ca), IRF - UQAT
• Nelson Thiffault (nelson.thiffault@nrcan-rncan.gc.ca), (CCFB)

En forêt boréale, les peuplements aménagés qui ne se régénèrent pas ou ne s'établissent pas rapidement après la récolte peuvent être rapidement envahis par l'aulne rugueux (Alnus rugosa), en particulier les sites humides où l'aulne était présent avant la coupe. Les populations denses d'aulnes résultent de l'augmentation de la lumière disponible et de l'élévation de la nappe phréatique après la récolte. L'invasion de l'aulne se fait principalement par multiplication végétative ce qui fait que cette espèce peut rapidement dominer un site, entrer en compétition avec la régénération forestière et provoquer des échecs de régénération. Toutefois, les racines d'aulne sont infectées par des actinomycètes fixateurs d'azote (N) qui pourraient contribuer à la croissance d'autres plantes par facilitation écologique. En outre, l'aulne joue un rôle important dans le budget d'évapotranspiration des tourbières boisées et peut abaisser le niveau de la nappe phréatique. Dans ce contexte, la présence d'aulnes pourrait favoriser la croissance des conifères dans les écosystèmes forestiers où la disponibilité en N du sol est faible et où la nappe phréatique se situe près de la surface. Par conséquent, dans les sites post-récolte où la densité de l'aulne est susceptible de nuire à la croissance des arbres et à la productivité forestière, des traitements de préparation de terrain pourraient être utilisés pour contrôler l'abondance de l'aulne en créant des conditions d'espacement où sa présence augmenterait la disponibilité de N et abaisserait la nappe phréatique, et pourrait favoriser la croissance de la régénération. L'objectif de ce projet est d'évaluer les effets de diverses méthodes de préparation de terrain (déchiquetage, décapage et inversion) sur la restauration de la productivité de sites forestiers dominés par l'aulne rugueux.

• Ziqi Ye (zye2@laurentian.ca), Laurentian University
• Peter Ryser (pryser@laurentian.ca), Laurentian University

Plant phenological pattern, as an important adaptation of plants in climates with an unfavourable season, is specific to species, but not much is known about the below-ground phenology. This study aims to clarify the inter-specific differences in seasonal growth patterns of roots and rhizomes and the consequences on the nutrient uptake, with focus on northern wetland plants known to differ in their root overwintering strategies; their roots either senesce in autumn, or survive the winter. For this purpose, a garden experiment was conducted for four ecologically-different wetland monocotyledonous plant species in Northern Ontario, with monthly harvests of whole plants over one year during the growing season and measuring nutrient uptake using a 15N stable nitrogen isotope tracer. Species with overwintering roots continuously produced roots from early April until late October, with a significant late-season growth spurt, 35-40% of the annual production happening after mid-September. Accordingly, their rhizomes showed the highest ?15N values in mid-October, indicating a strong nitrogen uptake by the roots late in the autumn. For species with autumn-senescing roots, root production mainly occurred between mid-April to late-July, with high mortality in late September. By mid-September, their leaves had mostly senesced, but the plants still took up the 15N tracer, indicating active root function until shortly before root senescence. During the beginning of spring (mid-March to April), rhizomes of all species deceased in biomass, meanwhile the alive roots of species with overwintering roots decreased in biomass by 30-36% with an increase of specific root length by 25-30%. The results show that different wetland plant root overwintering strategies are associated with distinct phenological patterns of root production, and with distinct seasonal patterns of nitrogen uptake. Besides their importance for late-autumn and early-spring nitrogen uptake, overwintering roots also seem to play an important role as storage organs for the early spring leafing-out.

• Marc-Frédéric Indorf (marc-frederic.indorf@uqat.ca), UQAT
• Tana Route (Tana.Route@uqat.ca), UQAT
• Yves Bergeron (Yves.Bergeron@uqat.ca), UQAT
• Nicole J. FENTON (nicole.fenton@uqat.ca), UQAT

In the remote area of Eeyou Istchee James-Bay in northwestern Québec, there is an important need to better understand vegetation communities and how they may interact with climate change and increasing human activities (mainly mining and hydroelectricity production). Since peatlands occupy 14-50% of the territory, we chose 36 undisturbed peatlands to study vegetation community assembly patterns across a 1000km gradient. We developed an innovative spatial-hierarchical approach combining classical ordination methods, indicator species analysis, and randomisation techniques to test assembly hypotheses at various spatial scales (territory, region, landscape, and site) and across different taxonomical groups (tracheophytes, bryophytes sensu lato, and lichens). Ordinations showed that Muskeg communities dominated by mature Black Spruce can be found across the entire territory. More open peatland communities, while difficult to characterise because of their composition differences, were organised into two groups following a latitudinal gradient. Surprisingly, environmental factors did not prove to be important for assembling communities at the regional scale. Results suggested instead either stochastic processes or an interaction between opposing factors (competition and environmental filtering on one side and facilitation and dispersal on the other). Coarser grain factors (e.g., climate and physiography) at the territorial scale did prove important for distinguishing regional species pools of tracheophytes, sphagna, and lichens, but not bryophytes sensu stricto nor liverworts. At the finest scale, biotic factors (e.g., facilitation) proved significant. While contributing to baseline knowledge of peatland communities in the territory, our results show that different taxonomical groups respond differently to scale and that environmental factors have little effect or their effects may be integrated with other scales and factors. This understanding of how different communities and taxonomical groups respond to various assembly factors is necessary for better understanding resistance-resilience capacities of these communities over the near future.

• Jérémy Fraysse (Jeremy.Fraysse@USherbrooke.ca), Université de Sherbrooke

Plus qu'un sujet de recherche scientifique, la biodiversité est désormais un enjeu sociétal, politique et économique important. De l'échelle microscopique des microorganismes à l'échelle macroscopique des animaux et des plantes, la biodiversité supporte d'innombrables services écosystémiques, cruciaux pour les sociétés à travers le monde. L'intensification des activités anthropiques et la perturbation des habitats, liée notamment à l'urbanisation croissante, affectent de manière importante la biodiversité et menacent directement la santé humaine.

Mon projet de recherche s'inscrira dans un projet multidisciplinaire soutenu par le Fonds Nouvelles Frontières en Recherche (New Frontiers in Research Fund) et dont le but est d'étudier les impacts directs et indirects des microbiomes, des contaminants aériens et des allergènes des arbres et plantes urbains sur la santé publique. Mon doctorat se concentrera sur le rôle des insectes dans l'assemblage et la diversité des communautés microbiennes, notamment présentes sur les plantes.

Ma recherche se définira selon trois axes principaux : (1) l'étude des communautés d'insectes à travers un gradient urbain et végétal constitué de trois villes du Québec : Sherbrooke, Québec et Montréal ; (2) l'identification et la quantification des communautés microbiennes présentes chez ces insectes (communautés externes et internes) mises en perspective du gradient urbain de l'étude ; et (3) l'interprétation du rôle que les insectes peuvent jouer en tant que vecteur dans la dispersion et donc la constitution des microbiomes dans les écosystèmes végétaux urbains.

Ce projet de recherche ambitieux et nouveau sera à l'interface de nombreuses disciplines telles que l'écologie, l'évolution, la microbiologie, l'entomologie, la santé et l'urbanisme. C'est avec un immense plaisir que je présenterai ma proposition de recherche lors de la conférence annuelle de l'Association Botanique Canadienne de 2022.

• Alexandra R. Golt (golt@unbc.ca), MSc Biology candidate (graduate student)
• Lisa J Wood (lisa.wood@unbc.ca), Associate Professor, PhD, RPF, University of Northern British Columbia

Glyphosate-based herbicides (GBH) are commonly used for vegetation management in forestry applications in British Columbia (BC). Aerial applications of GBH in harvested cutblocks result in forest-understory plants receiving often a sublethal application of GBH and developing growth abnormalities as a consequence. Prior research indicates sublethal GBH applications caused male sterility in agriculturally relevant plants, highlighting a need to determine impacts of forestry-related GBH applications on understory plants. We investigated the effects of GBH on reproductive morphology of the prevalent understory shrub Rosa acicularis. We collected flowers across three forestry cutblocks in northern BC treated with GBH one-year, and two-years prior to sampling, and also in a controlled experiment. We analyzed floral and pollen morphology from treated plants and compared these with untreated plants in both scenarios. Pollen viability of treated plants decreased by an average of 66%, and >30% of anthers were non-dehiscent compared to controls across our three field sites and experimental plants. We also found alterations in pollen and petal morphology in flowers from treated sites and glyphosate residues present in floral tissues 2 years after GBH applications. Based on these results, we are continuing this research to better understand biocommunication between plants and pollinators in GBH treated forests. Plants such as Rosa acicularis are vital food sources for a plethora of wildlife. Changes in reproductive morphology could have wide-ranging impacts on pollinator species and foraging animals, and the overall health of the forest. We hope this research will inform forest ecologists and managers and motivate the re-evaluation of current practices to minimize the effects of GBH on wild plants. It is important to fully understand how long GBH-induced change will impact forest vegetation, to preserve natural forest biodiversity and reduce anthropogenic influences on boreal forest ecosystems.

• Mark E. Samuels (mark.e.samuels@umontreal.ca), Centre de Recherche du CHU Ste-Justine, Université de Montréal
• Etienne Léveillé-Bourret (etienne.leveille-bourret@umontreal.ca), Université de Montréal, Département de sciences biologiques et Institut de Recherche en Biologie Végétale
• Cassandra Lapointe (cassandra.lapointe@umontreal.ca), Université de Montréal, Département de biochimie
• James Moncho (james-alexander.moncho@hotmail.com), Université de Montréal, Département de biochimie
• Jean-Alexandre Guilmette (jean-alexandre.guilmette@umontreal.ca), Université de Montréal, Département de biochimie
• Sara Halwas (sara.halwas@umanitoba.ca), University of Manitoba, Department of Biological Sciences
• Anne Worley (anne.worley@umanitoba.ca), University of Manitoba, Department of Biological Sciences

Background and Objectives: Chenopodium berlandieri, pitseed goosefoot, is a native Canadian close relative to Chenopodium quinoa. Quinoa was domesticated in South America, whereas C. berlandieri, now found only wild in Canada, was cultivated throughout parts of North America before the arrival of European settlers. C. berlandieri could thus someday be a valuable new food crop, as it is already adapted to the Canadian climate although requiring re-domestication. Toward that long-term goal, the project has three objectives: 1) Develop barcoding markers to identify C. berlandieri; 2) Carry out new collections of C. berlandieri near regions where it was once cultivated; 3) Perform whole genome sequencing for comparison to quinoa and C. berlandieri from the United States. Results: We have identified a set of molecular barcode markers that appear to distinguish berlandieri-like plants from other Chenopodia. We have collected plants at multiple sites in the greater Montreal area. All of the newly collected plants are C. album-like based on barcoding, with a possible exception now under analysis. We confirmed the identification of C. berlandieri previously collected in Manitoba. We performed whole genome sequencing of one such plant using Illumina paired-end short reads, followed by genome assembly using Platanus. To our knowledge this is the first example of genome sequencing of Canadian C. berlandieri. The assembly is highly fragmented, as expected for a genome with high repetitive sequence content, with an N50 of 6.6kb, and several scaffolds longer than 100kb. 63% of the genome was defined as repetitive by RepeatMasker. BUSCO analysis identified at least 80% of a set of basic plant genes in the assembly. As expected, the assembly is highly similar to the published genome of C. quinoa. We are analyzing the assembly in comparison to the quinoa genome to look for variations that might be relevant to quinoa domestication.

• Sarah Poirier (sarah.poirier2@usherbrooke.ca), Université de Sherbrooke
• Isabelle Laforest-Lapointe (isabelle.laforest-lapointe@usherbrooke.ca), Université de Sherbrooke
• Catherine Girard (catherine5_girard@uqac.ca), Université du Québec à Chicoutimi

Dans ce projet, nous nous appuierons sur différentes disciplines telles que la microbiologie, l'écologie microbienne et la génomique pour identifier les moteurs des bioaérosols urbains. Nous testerons l'hypothèse selon laquelle la diversité des infrastructures vertes est le facteur le plus important de la quantité et la diversité des bioaérosols (pollens et microorganismes) ainsi que l'hypothèse selon laquelle il y a une corrélation entre la biodiversité des bioaérosols et le gradient socio-économique dans les villes. Pour ce faire, nous utiliserons 25 pièges à dépôts répartis spatialement le long de gradients socio-économiques à Montréal, Québec et Sherbrooke. Il y aura aussi quelques pièges à Chicoutimi. Au cours de l'été 2022, différents types d'échantillons seront collectés. Nous collecterons (1) des échantillons de pollen chaque deux semaines à partir de chaque piège de mai à septembre pour identifier et quantifier les pollen du site, (2) des échantillons de feuilles à trois reprises durant l'été (mai, juillet, septembre) à partir des arbres et arbustes les plus communs près des pièges pour identifier et quantifier les microbes potentiellement émis par les infrastructures végétales locales, et (3) des échantillons de microbes et de pollen dans l'air près des pièges à trois reprises durant l?été (mai, juillet, septembre), en même temps que les échantillons de feuilles pour identifier et quantifier les bioaérosols urbains. Ces trois types d'échantillons seront utilisés pour identifier et quantifier les pollens et les microbes dans les centres urbains. Les données sur la diversité végétale locale seront obtenues à partir des bases de données municipales et la location des trappes sera choisie selon un gradient socio-économique, déterminé par le code postal avec les données du recensement 2021 du Canada. Avec ce projet, nous construirons des modèles prédisant la diversité et la quantité de bioaérosols locaux dans les villes, fournissant ainsi des informations clés aux urbanistes.

• Nicholas Hill (fernhillns@gmail.com), St. Francis Xavier University
• Sean Blaney (sean.blaney@accdc.ca), Atlantic Canada Conservation Data Centre
• James Churchill (james.churchill@accdc.ca ), Atlantic Canada Conservation Data Centre
• David Garbary (dgarbary@gmail.com ), Biology Department, St. Francis Xavier University

Climate change influences ecological process and biodiversity worldwide. Recovery documents that previously listed such impacts as unknown or low, now score its threats. Recently, the vulnerability of the sub-boreal black ash to emerald ash borer was linked to warming. The arctic-alpine Eastern Mountain Avens (Geum peckii) had the highest threat calculator scores yet showing that warming is threatening the existence of a nationally Endangered species. We previously documented an average climate normal shift (1961-1990 to 1991-2020) of + 0.8oC in average annual temperature for Nova Scotia. We then documented the Brier Island fens of Avens had experienced the greatest temperature increase in Nova Scotia (1.65oC) with overwinter warming of 2oC leading to potential competitive exclusion of Avens from shrub competition. Here, we dig in to possible impacts on rare plants (S3 vulnerable to S1 critically imperilled) of southern (Atlantic Coastal Plain and Appalachian Deciduous) and northern (Boreal/Arctic-Alpine) plant elements. These elements were laid out by Roland and Smith (1969, The Flora of Nova Scotia) and reflect North American geographic affinities and habitat types. The strongholds of rare species of three plant elements were found to be non-overlapping and determined by geological and climate patterns. Results suggest the range of the coastal plain flora can extend north 1o latitude into the eastern Meguma, that of the deciduous forest flora should diversify in lowland Cape Breton and the boreal/arctic-alpine flora in grave jeopardy on Brier Island, may persist at high elevation in Cape Breton where overwinter temperatures are severe and vegetation is sculpted by high winds. Real warming numbers are filling gaps in recovery plans, reinforcing the need to maintain and renew the legacy of weather stations to inform climate change conservation management.

• Faezeh Aliabadi (faezeh.aliabadi@botany.ubc.ca), The University of British Columbia, Vancouver, Canada
• Ludovic Le Renard (ludovic.lerenard@gmail.com), The University of British Columbia, Vancouver, Canada
• Alice Ma (alice.ma342000@gmail.com), The University of British Columbia, Vancouver, Canada
• Mary L. Berbee (mary.berbee@gmail.com), The University of British Columbia, Vancouver, Canada

Metacapnodiaceae S. Hughes & Corlett is a family of sooty mold fungi. Sooty molds produce loose and interwoven hyphae as black spongy matts on leaves, twigs, and trunks. Fossils of this family are preserved in amber but their interpretation is hindered by a lack of resolution of relationships of living species. Morphological studies have led to two hypotheses about the placement of Metacapnodiaceae within Ascomycota. The family may either be accommodated in class Dothideomycetes or class Eurotiomycetes. To resolve the relationships of Metacapnodium, we are sequencing multiple genes (ITS1 & ITS2 and ITS 5.8S rDNA, SSU, LSU, RPB2, EF1-α) from a cultured specimen to infer the phylogenetic systematic position of Metacapnodiaceae. Our ribosomal gene sequences show that Metacapnodium is related to Eurotiomycetes, rather than Dothideomycetes. Combining sequences from our work, from M. neesii by Sugiyama et al., and from the Joint Genome Institute's whole-genome projects, we show that Metacapnodium is a sister-group of order Verrucariales, rather than Chaetothyriales or Phaeomoniellales, as previously suggested. These results show the potential to improve the phylogenetic resolution of the relationships of Metacapnodium using more than one gene locus and large-scale taxon sampling. With continuing research, we will use comparative morphology and ITS sequences to refine species delimitation in Metacapnodium. Improved resolution of relations of Metacapnodium species will contribute to the interpretation of Metacapnodium fossils and understanding of the geological timing of Ascomycota diversification.

Keywords: Biodiversity, Metacapnodiaceae, phylogeny, sooty molds, morphology

• Mary Ann C. Perron (mperr058@uottawa.ca), University of Ottawa & St. Lawrence River Institute
• Frances R. Pick (Frances.Pick@uottawa.ca), University of Ottawa

Stormwater ponds are constructed to mitigate floods but are also some of the only available wetland habitats in cities. Wetland plants will colonize stormwater ponds, but these ponds are often highly disturbed potentially affecting the quality of plant communities. In this study we (1) describe wetland plant communities at stormwater ponds and compare them to natural ponds, and (2) determine the effects of urbanization and pond age on wetland plant diversity patterns. Plant communities were characterized at 41 stormwater ponds and 10 natural ponds in the National Capital Region of Canada. We found that stormwater ponds generally had fewer obligate wetland plant species and lower overall floristic quality when compared to natural ponds. The species richness of obligate wetland plants at stormwater ponds was negatively associated with the proportion of surrounding urban land cover. However, pond age was not significantly associated with wetland plant species richness. Improved design of these systems can enhance wetland habitat in cities which has implications for wetland fauna drawn to stormwater ponds.

• Sohiba Khayol Muhammad (sohiba@dal.ca), Dalhousie University
• Arunika Gunawardena (arunika.gunawardena@dal.ca), Dalhousie University
• Sophie Tattrie (sp490888@dal.ca), Dalhousie University

The lace plant (Aponogeton madagascariensis) exhibits a unique form of programmed cell death (PCD) by forming perforations throughout its leaf lamina in a highly predictable manner. PCD initiates in the center of areoles in early-stage leaves abundant in anthocyanin, a potent antioxidant. Its loss from specific cells initiates the accumulation of reactive oxygen species (ROS) and the beginning of cell death. Indole acetic acid (IAA), auxin?s most common form, is an important phytohormone and has been implicated in the lace plant?s PCD process. PINFORMED1 (PIN1) efflux proteins direct the auxin flow via polarization, however, the exact role and direction of auxin flow within an areole are unknown. This study aims to determine whether an excess amount of auxin hormone can alter perforation formation or affect key regulators of PCD by quantifying anthocyanin, detecting ROS, and determining the direction of auxin flow via immunolocalization of PIN1 proteins. Pharmacological experiments were conducted on lace plants with IAA concentrations 0 (control),1,5,15,50 and 100 ?M. Leaves were harvested, and data was collected on leaf length, leaf width, leaf area, and the number of perforations. Quantitative and qualitative anthocyanin changes were determined using microscopic and spectrophotometric analysis. Results revealed that plants treated with 15-100 ?M IAA showed a slight decrease in perforation number per cm² however a significant difference was only observed in 50&100 ?M treatments. The was a slight increase in leaf length in treatments 5-100 ?M, however, no significant difference was observed. No changes in leaf width were seen among treatments. All IAA treatments showed a significant decrease in anthocyanin concentration compared to the control. Our results suggest an optimal concentration of auxin is crucial in the PCD mechanism and perforation formation. Immunolocalization of PIN1 proteins and ROS detection are currently under investigation.

• Melanie Jones (melanie.jones@ubc.ca), University of British Columbia, Okanagan campus

In this presentation, I will highlight some observations, made over a career of more than 40 years of studying ectomycorrhizal (ECM) symbioses, that may be useful to students entering the field. When conducting lab studies, it is important to remember that ECM fungi growing in pure culture differ physiologically from those in symbiosis. This is especially relevant when ECM fungi are ranked for their ability to take up a particular nutrient, or their tolerance to a toxic material. While it is becoming common to generalize about the role of ECM fungi in nutrient cycling, we must remember ECM fungal species differ considerably. Colonization by some ECM fungi may stimulate nutrient uptake relative to non-mycorrhizal roots, whereas others may inhibit uptake. Furthermore, like all organisms, ECM fungi exhibit phenotypic plasticity. Hence, when examining physiological traits on EM roots harvested from the field, be aware that traits can vary for the same fungus in different soil environments. This is especially important when making inferences about local adaptation of ECM fungal communities. When testing for inoculum potential of a site, an in situ bioassay is much more suitable than a pot study in a greenhouse. This is because some ECM fungi colonize much more readily from hyphae already associated with a mycorrhiza than from fragmented hyphae or from spores. Finally, while many plot-scale treatments can influence the ECM fungal community on tree roots, local species pools will still have a substantial, often dominant, influence on community assembly.

• Trinitas Evette Chisholm (chisholm@uleth.ca), MSc. student, Biological Sciences, University of Lethbridge
• Jenny McCune (jennylynmccune@hotmail.com), Assistant Professor, Biological Sciences, University of Lethbridge

As both the popularity of recreation in protected areas and the human population increase, the number of trails and the intensity of their use will also increase, intensifying the impact on the surrounding ecosystem. In protected parks concerned with balancing increasing visitors and conservation goals, it is important to understand how trails affect plant communities. Although there are many studies that look at the impact of trails on fauna, there are few studies that directly measure trail impact on plant communities, particularly in southwestern Alberta. Our research investigates the impacts of recreational trails on plant species diversity in Castle Provincial and Castle Wildland Provincial Parks (herein, CWPP), a hotspot for provincially rare plants. We surveyed plant communities along trails that vary in trail use and vegetation. We then quantified the effects of trails on the occurrence of exotic and rare species. We predicted that exotic plant species would occur more often near trails, and that the presence of rare plant species would decrease near trails, especially near off-highway vehicle (OHV) trails. We found that exotic species in CWPP are more likely to occur near trails. The probability of finding exotic species more than 5m from a trail was greater for OHV trails than for footpaths. However, neither distance from trail nor trail type were significant predictors of rare species presence. The trails we surveyed do not seem to impede the occurrence of provincially rare species, however this should continue to be assessed in the future. Our results do indicate that exotic species have spread farther away from OHV trails than footpaths. Results from our research can help guide management of trail systems, by informing park management of trails acting as conduits for exotic species that could potentially become invasive to those areas of the parks.

• Katharina Braeutigam (katharina.braeutigam@utoronto.ca), University of Toronto Mississauga
• Oscar Nunez (oscar.nunez@utoronto.ca), University of Toronto Mississauga
• Stefan Heinen (stefan.heinen@utoronto.ca), University of Toronto Mississauga

In addition to the genetic information, epigenetic factors play central roles in shaping cell function and ultimately phenotype. Such factors can modify chromatin structure, modulate gene expression, and thus contribute to genome interpretation and function. Here, we investigate the role of epigenetic marks in reproductive development in Populus, i.e. trees with a wide natural distribution and economic importance in Canada. Sexual reproduction is one of the most important processes for almost every form of life: it ensures genetically diverse offspring and therefore the ability to survive in an ever-changing environment. Despite this, little is known about sex determining mechanisms in some of our crop and forest species. Just recently, the mechanism of sex determination has been uncovered in poplars. Similar to humans, poplars separate male and female function onto different individuals (dioecy). Here, we study high-resolution epigenome maps with respect to sex determination in the genus Populus. Using unbiased machine learning approaches on complex epigenome profiles allowed us to recently identify the central regulator of sex, a response regulator specific to female development. In males this regulator is silenced via RNA-directed DNA methylation. Further in-depth analyses of full male and female developmental programs from reproductive meristems to mature flowers indicated successive waves of chromatin alteration to co-ordinate gene expression and to ensure correct spatial and temporal development. The discovery of this central regulator now raises interesting questions related to developmental pathways, its relevance in a broader taxonomic context, or the application of this knowledge in silviculture. Moreover, approaches can be expanded to advance our understanding of other developmental paths in forest trees and beyond.

• Cristopher Albor (c.albor@hotmail.com), University of Calgary
• Jana Vamosi (jvamosi@ucalgary.ca), University of Calgary
• Joanne Bennett (joanne.bennett@canberra.edu.au), University of Canberra
• Gerardo Arceo-Gomez (gtarceo@hotmail.com), East Tennessee State University
• Itay Mayrose (itaymay@gmail.com), Tel Aviv University
• Tiffany Knight (tiffany.knight@idiv.de), Martin Luther University Halle-Wittenberg
• Tia-Lynn Ashman (tia1@pitt.edu), University of Pittsburgh

It is estimated that 30 % of flowering plants are polyploid, which is predicted to lead to phenotypic adaptations that increase plant reproductive success. However, there is still limited evidence of whether the polyploid origin is associated with higher reproductive success. Studies have shown that polyploidy can lead to changes in floral morphology that enhance species' reproductive success by increasing their attraction to pollinators. Thus, understanding the mechanisms by which polyploidy has shaped floral trait diversification in angiosperms and increased the reproductive success of polyploid lineages is essential to recognize their persistence in angiosperm evolutionary history. Here we use the global pollen limitation database (GloPL database) and polyploidy level estimations (i.e., polyploid vs. diploid origin) to determine whether polyploid species are less pollen limited (i.e., higher reproductive success) than diploid species. In addition, we evaluated phenotypic differences in floral traits associated with pollination attraction (corolla length, corolla width, and floral display) between ploidy levels and their relationship with the degree of pollen limitation. We found that polyploid species are less pollen-limited than diploid species. Moreover, this pattern was persistent in all major angiosperm groups (i.e., Monocots, Asterids, Rosids, and basal angiosperms). Contrary to our expectations, polyploid species had smaller flowers and higher floral density than diploids. Further, we found a positive correlation between floral size and pollen limitation. Thus, species with small flowers that are likely to be polyploid are less pollen-limited, while species of larger flowers that are likely to be diploid are more pollen-limited. Overall, our results suggest that the high reproductive success of polyploids mediated by floral trait differentiation may explain the persistence and widespread of polyploidy through the angiosperm evolutionary history.

• Kendra Sampson (kendra.sampson@smu.ca), Saint Mary's University
• Jeremy Lundholm (Jeremy.lundholm@smu.ca), Saint Mary's University
• Allison Walker (allison.walker@acadiau.ca), Acadia University
• Danika van Proosdij (dvanproo@smu.ca), Saint Mary's University

Salt marshes are highly productive blue carbon ecosystems that accumulate and store large amounts of carbon. The increasing loss of these ecosystems reduces global carbon storage capacity and climate change mitigation abilities. Carbon is accumulated through suspended sediment and autochthonous sources within the salt marsh, which may be utilized by salt marsh vegetation and fungal associates. Beneficial arbuscular mycorrhizal fungi (AMF) form associations with salt marsh plant roots. AMF receive fixed carbon from their host plant, and in return, provide the plant with mineral nutrients and an increased surface area, which leads to greater below ground carbon storage. We are investigating the role of AMF in carbon sequestration. We assessed AMF in dominant salt marsh plant species (Sporobolus, formerly Spartina), from low to upper high elevations at 11 sites fringing the Bay of Fundy, Nova Scotia, and examined the correlation between organic carbon and AMF colonization. Additionally, we are analyzing mycorrhizal contributions to belowground carbon storage. We compared a chronosequence of restored marshes to reference salt marshes, by collecting sediment cores at each site over multiple years. Preliminary results show high AMF colonization rates and high organic carbon densities at new, intermediate, and old restored sites for each vegetation type (S. alterniflorus, S. pumilus, S. michauxianus). These results show a potential correlation between AMF colonization and rhizosphere organic carbon and indicate that AMF could be contributing to autochthonous carbon storage. This research will fill many knowledge gaps on the role of beneficial below ground fungi in salt marshes and their contribution to carbon accumulation and storage. Fungal influence on carbon storage as well as the importance of carbon sequestration in salt marshes are novel areas of research in Atlantic Canada. Our study will inform future salt marsh restoration projects in the Canadian Maritimes.

• Timothy A. Dickinson (tim.dickinson@utoronto.ca), Royal Ontario Museum & University of Toronto
• Roman Ufimov (Roman.Ufimov@bfw.gv.at), Austrian Research Centre for Forests, Vienna, Austria & Komarov Botanical Institute, St. Petersburg, Russian Federation
• Roswitha Schmickl (roswitha.schmickl@natur.cuni.cz), Institute of Botany, The Czech Academy of Sciences, Pruhonice, Czechia & Department of Botany, Charles University, Prague, Czechia
• Deborah A. Metsger (debm@rom.on.ca), Royal Ontario Museum, Toronto, Ontario, Canada

Herbarium specimens document the past research projects that led to their being collected, as well as the floras from which they were collected. Herbarium specimens also provide baseline data on the existence of, and variation in, plant species. Looking forward, herbarium specimens may provide material with which to make preliminary evaluations of ecological or taxonomic hypotheses that arise from field observations, reviewing the literature, or from first principles. Canada's largest Crataegus herbarium, housed in the Green Plant Herbarium of the Royal Ontario Museum (TRT) is a good example, thanks to the 2011 gift to the ROM of the J. B. Phipps Hawthorn Research Collection by the University of Western Ontario. We describe some of the strengths of the ROM collection (including components resulting from ROM-based research), give examples of recent uses, and suggest new research questions, the resolution of which could begin by collecting data from specimens in TRT.

• Darwyn Coxson (darwyn.coxson@unbc.ca), University of Northern British Columbia

Inland temperate rainforests (ITR) of western North America were historically dominated by old-growth forests (OGF), supporting rich plant communities with affinities to both coastal temperate rainforests and northern boreal forests. Many of the OGF dependent species of the ITR, from deep-snow mountain caribou to the canopy lichen communities upon which they forage, are now threatened by the rapid pace of OGF loss, primarily due to clear-cut logging. BC's ITR landscapes, which historically were comprised of 80 to 90% OGF, now contain less than 25% OGF. Equally important, remaining OGF stands have been highly fragmented by current forestry practices. Recent analysis suggests that less than 5% of the BC ITR remains as functional "interior" old-growth forest habitats. This has dramatic implications for a wide range of OGF dependent organisms, from oceanic lichens, such as Lobarion group lichens, where edge effects can extend for more than 100 m inward from stand edges, to keystone predators, such as the northern goshawk, where population collapse has rapidly followed landscape fragmentation. Management practices promoting dispersed small cut blocks across wide landscape areas must urgently be reconsidered if we are to avoid ecosystem collapse in the inland temperate rainforest.

• Shanukie M. Embuldeniya (shanukie.embuldeniya@dal.ca), Dalhousie University
• Shawna MacKinnon (shawna.mackinnon2@canada.ca), Kentville Research and Development Station, Agriculture and Agri-food Canada
• Kerry B. Goralski (kerry.goralski@dal.ca), Department of Pharmacy, Dalhousie University
• Arunika N. Gunawardena (arunika.gunawardena@dal.ca), Department of Biology, Dalhousie University

Aponogeton madagascariensis, commonly known as the lace plant, is an aquatic monocot that forms perforations along the leaf veins during leaf morphogenesis. Perforation formation has been divided into five developmental stages: pre-perforation, window, perforation formation, perforation expansion and mature. One of the most indicative signs of perforation formation is the gradual loss of the vacuolar pigment anthocyanin between the window and mature stages. Anthocyanins are bioactive compounds that are known to have anti-cancer and anti-diabetic properties. However, their solubility and instability in different environments need to be considered when selecting an effective anthocyanin extraction method for extracts that will be used in health and food research. In this study we compared the bioactivity of anthocyanins extracted from window and mature stages of the lace plant leaves using two solid-liquid extraction methods and measured their cytotoxic effects in triple negative MDA-MB-231 breast cancer cells. In each extraction method, plant tissues were macerated and incubated in an acidified extraction solvent and the subsequent removal of the solvent was accomplished by either drying in a controlled temperature chamber or by using nitrogen gas. Spectrophotometry analysis was used to determine the anthocyanin yield by measuring absorbance between 480 - 600 nm. A 3- [4,5dimethylthiaremoval of the zol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to measure metabolic activity of MDA-MB-231 cells by reading absorbance for the reduction of yellow tetrazolium salt to purple formazan crystals in viable cells. A High-Pressure Liquid Chromatography profiling was conducted to compare anthocyanin content between the two extraction techniques. The findings of this study shows that the extraction method affects the bioactivity of anthocyanins and that extraction parameters should be considered to ensure optimal bioactivity of anthocyanins in applied health and food research.

• Annie DesRochers (annie.desrochers@uqat.ca), IRF - UQAT

Trees are traditionally considered as discrete entities, despite the fact that natural root grafting (anastomosis) commonly occurs between trees of the same species. Furthermore, some vegetatively-regenerated species such as poplars share communal root systems, forming large physiological units. Root connections and grafts allow trees to share substances such as water and minerals, sugars, hormones or diseases and may in this way affect forest dynamics and inter-tree relationships. Although we have known for some time that trees can indirectly act on their neighbors by modifying their common environment through root exudates, mycorrhizae, or altered soil conditions through shedding of plant parts, we now know that they can directly alter growth of their neighbours, positively or negatively, through these connections. Grafted stumps have been found to survive for many years after their crown has been removed or dead, and physiological reactions can be triggered by grafted neighbor trees subjected to stress. Classic notions of forest ecology such as competition and succession are thus challenged by this notion of direct interactions between trees through roots, as are some of the bases for application of silvicultural treatments in forests where occurrence of root grafting is common. Root grafting can generate both positive and negative interactions in forest communities, and the balance between them largely remains to be explained. This presentation will review some examples of physiological integration of trees through root connections and grafts and the ecological significance of natural root grafting between trees and its implication for forest management will be discussed.

• Mélanie Roy (melanie.roy@univ-tlse3.fr), Université Toulouse 3 Paul Sabatier

Soils are havens of diversity, and the site of symbiotic interactions between plant roots and mycorrhizal fungi, essential for the growth and survival of the majority of plant species. Nevertheless, the consideration of these interactions – almost invisible – in forest management and conservation remains limited. The discovery of mycorrhizal networks but also the explosion of high-throughput sequencing techniques are today revolutionizing our vision of soil diversity and the functions of plant-fungi interactions. Recent studies highlight the central role of mycorrhizal communities in temperate and boreal forests, but also their potential functions in the adaptation of forests to global changes, or their resilience. To study the resilience and the long-term impact of global changes on soil communities and their interactions, the knowledge of forest history, and in particular the study of ancient forests, constitutes an open-air laboratory. This conference questions the links between management and forests history, their impacts on mycorrhizal communities and soil biodiversity, in boreal and temperate environments, and more generally aims at discussing the contribution of these interactions, or their networks, to the adaptation and resilience of forests face to global changes.

• Maxence Martin (maxence.martin@uqat.ca), Université du Québec en Abitibi-Témiscamingue / Université du Québec à Chicoutimi
• Hubert Morin (hubert_morin@uqac.ca), Université du Québec à Chicoutimi
• Osvaldo Valeria (osvaldo.valeria@uqat.ca), Université du Québec en Abitibi-Témiscamingue

Old-growth boreal forests provide critical habitats and ecosystem services in the current context of global biodiversity loss and climate change. Anthropogenic disturbances have caused major erosion of their area and connectivity, making the conservation and restoration of old-growth forest a major forest management issue. However, our research projects identified important limitations in our vision of old-growth forests in boreal landscapes, which may question the efficacy of current management measures related to these forests. (i) Old-growth forests are still often seen as relatively homogeneous and static. Their internal diversity, in terms of structure or habitats such as deadwood and tree-related microhabitats, and their dynamism are therefore little considered in forest management strategies. Yet, these characteristics explain in large part the high ecological value of old-growth forests. (ii) Anthropogenic disturbances, particularly logging, primarily target the most productive and accessible old-growth forests, in contrast to natural disturbances such as wildfires. There is therefore a significant risk that the diversity of habitats and functions provided by old-growth forests will not be maintained in managed areas, due to a loss of representativeness in comparison to preindustrial landscapes. (iii) Field or remotely sensed forest surveys generally provide little information on the characteristics of old-growth forests (e.g., structure, age, habitats), severely limiting the application of effective management strategies. Remote sensing technologies, such as LiDAR and satellite imagery, can however provide an increasingly detailed picture of old-growth forest characteristics. The development of new remote sensing tools, combined with the acquisition of a finer ecological knowledge of old-growth forests, are therefore major research axes to ensure the sustainable management and conservation of these forests of critical importance.

• Isabel Molina (isabel.molina@algomau.ca), Department of Biology, Algoma University, Sault Ste Marie, ON, Canada

Plants have evolved constitutive and induced defense mechanisms that are critical to their survival. The periderm that covers roots, tubers and tree bark is one example of constitutive physical barriers. When plants are naturally or artificially injured, a wound periderm is formed to restore control over desiccation and limit pathogen invasion. Both natural and wound-induced periderms consist of three tissues: phelloderm, phellogen (cork cambium), and phellem (cork). Cork cell walls are modified with suberin, a heteropolymer that forms the first barrier of defense against pathogen penetration and controls water and ion fluxes. Current models describe suberin as a polyester of fatty acids and glycerol that is cross-linked with a lignin-like polymer and associated with solvent-soluble waxes. Such structural models have been inferred from chemical depolymerizations, but the insoluble nature of this polymer makes analyses challenging and, consequently, the native structure of suberin remains unclear. Much of the current research on suberin biosynthesis has focused on Arabidopsis thaliana and wound-healing potato (Solanum tuberosum) models. However, the complete biosynthetic pathways have not yet been fully characterized and it is unclear how knowledge derived from Arabidopsis or potato tuber translates to woody tree periderms. We have generated a cork transcriptome database and optimized chemical methods to investigate the biosynthesis and structure of this refractory material in the model tree Populus trichocarpa (Poplar) by forward and reverse genetic approaches. Our contributions to this area will be summarized.

• Samuel Robin (Samuel.Robin@uqat.ca), UQAT - GREMA
• Miguel Montoro Girona (miguel.montoro@uqat.ca), UQAT - GREMA
• Annie Desrochers (annie.desrochers@uqat.ca), UQAT - GREMA
• Sergio Rossi (sergio_rossi@uqac.ca), UQAC

Les changements climatiques altèrent la structure et la fonction des écosystèmes forestiers dans le monde entier. En ce qui concerne les forêts boréales, une augmentation de la température de 4°C à 11°C est prévue pour le prochain siècle. Ces conditions modifieront les processus physiologiques des arbres boréaux, dont l'adaptation qui aura du mal à suivre le rythme de ces changements. Pour cette raison, des études visant à mieux comprendre les processus de régénération des espèces boréales dans un climat en réchauffement deviennent pertinentes pour adapter nos stratégies de gestion forestière. Ce projet vise à évaluer les effets des températures prévues pour le prochain siècle sur la germination et l'établissement des espèces d?arbres boréales canadiennes. Notre plan expérimental comprenait quatre scénarios de températures de germination (14°C, 18°C, 22°C et 26°C) et trois scénarios de températures d'établissement (16°C, 22°C et 28°C). L'expérience a été menée dans des chambres de croissance afin d'isoler les effets de la température sur les arbres. Nous avons mesuré le taux de germination, la viabilité des semences, la vitesse de germination et la biomasse des semis produits de huit espèces : Pinus banksiana, Betula papyrifera, Populus tremuloides, Abies balsamea, Picea glauca, Picea mariana, Larix laricina et Thuja occidentalis. Nous nous attendions que des températures de germination élevées produisent des semis mieux adaptés à de fortes températures durant leur croissance, comparativement à des semis résultant de températures de germination plus froides. Nous avons observé que le taux de germination diminuait pour Populus tremuloides, Larix laricina et Abies balsamea avec l'augmentation de la température, alors que c'était le contraire pour les autres espèces. Ces connaissances seront essentielles pour mieux estimer la vulnérabilité et la résilience de nos forêts face aux changements climatiques dans les années à venir.

• Trevor Goward (trevor.goward@botany.ubc.ca), UBC Herbarium, Beaty Museum

The Inland Temperate Rainforest (ITR) of southern inland British Columbia comprises an ?archipelago? of about ten major and several minor islands formerly cloaked in continuous stands of late-successional conifer forests but now severely fragmented by industrial logging. The ITR supports a diverse assemblage of epiphytic (tree-dwelling) lichens including numerous species dependent on oldgrowth ecosystems. As a rule, the distributions of these oldgrowth-dependent epiphytic lichens (ODELs) are more or less discontinuous at landscape scale, in most cases aligning less closely with the structural attributes emphasized in traditional definitions of /oldgrowth/ than with such non-structural, spatially heterogeneous variables as host-tree identity, soil nutrient status, topographic position and proximity to standing water. Indeed, the single most important feature of oldgrowth forests to ODELs is likely their relative environmental stability. In light of these observations, I suggest: (1) that advanced forest age is a necessary but not necessarily sufficient requirement of ODELs; (2) that oldgrowth forests are helpfully viewed as habitat mosaics, wherein each component habitat optimally favours a unique set of ODELs; and (3) that the stand-scale presence/absence of most ODELS is less a by-product of oldgrowthness /per se/ than an emergent property of the complex interplay of component habitats against a backdrop of source-sink dynamics. This thought experiment invites two inferences. First, the ongoing fragmentation of the ITR threatens ODELs not only through physical habitat reduction, but also through differential disruption of long-established habitat mosaics, with inevitable cascading effects on source-sink relationships. And second, forest science would benefit from a clear distinction between /old growth/ and /oldgrowth/, with the first emphasizing forest age and structure, and the second ecosystem process.

• André Arsenault (andre.arsenault2@canada.ca), Canadian Forest Service, Natural Resources Canada

Canadian rainforests tend to have more variety and abundance of old trees, old forest attributes, and old-growth forests when compared to their adjacent drier forest counterparts. The coastal temperate rainforests on the west coast, the temperate inland rainforest of British Columbia?s intermountain regions and the hemi-boreal and boreal rainforests on the East coasts have interesting similarities in their epiphytic lichen distributions and the dynamics of the trees they live on and the forests they live in. Not surprisingly, they harbor numerous oceanic lichens, many of which are rare or at risk. In this paper, I will share with you some of the insights I have gathered with colleagues on the forest dynamics and lichen biodiversity of coastal rainforests over the last 30 years. Our study areas include Clayoquot Sound, the Vancouver watersheds, the Avalon and south coast forests of Newfoundland, and the Northshore of Quebec. Old-growth rainforests in Canada include some of the most at risk ecosystems in our country, and as we have demonstrated with lichens, a major source of biodiversity. Our forest dynamics research has shown that forestry assumptions about the ecology of coastal old-growth rainforests in Canada are often incorrect. We suggest that moving forward on the conservation of old-growth coastal rainforests will require a more robust integration of science into forest management, planning, and operations. Our approach in integrating science and indigenous knowledge for biodiversity monitoring in the coastal rainforests of Newfoundland is a promising attitude of using different knowledge systems for ecological conservation. Applying this model in a forest management context could prove innovative and transformative.

• Uwe Hacke (hacke@ualberta.ca), Dept. of Renewable Resources, University of Alberta

Winter frost is a challenge for the integrity of the vascular cambium and the function of vascular tissue. The cambium produces vascular tissue, but growth can only occur when temperatures are favorable, and in the absence of frost. I will discuss how cambial activity changes over the course of the season looking at four tree species growing in Edmonton, Alberta. I will then discuss how water transport in the xylem is constrained by freezing-induced embolism, again using trees in Edmonton as an example. While we have a fairly good understanding of xylem transport, and how it changes throughout the seasons, we know much less about seasonal changes in the sugar conducting phloem. Sieve plates generate a major resistance to flow in the phloem, even when the pores are open, i.e., not occluded by callose. Some older literature reports suggest that pores are blocked by callose in the winter. We studied this question in five boreal species, and I will discuss our findings.

• Marianne Ignace (marianne_ignace@sfu.ca), Simon Fraser University

In this presentation, based on several decades of work by Marianne and kukpi7 Ron Ignace with Secwepemc elders in the Interior of British Columbia, I explore ways in which Secwepemc people, in philosophy, knowledge and action articulate human relationships with what amount to old growth forests. To begin, the philosophical and metaphoric underpinnings of this relationship at the beginning of human history tell us of the special relationship established with trees in that Sk'elep, the cultural transformer, married a tree to start human society and interactions with the land and environment, and thus enabling the livelihood of future generations of humans on and with the land (tmicw), as a kincentric relationship. Throughout 10,000 years of living in what became Secwepemcul'ecw, the homeland of the Secwepemc, our people developed detailed knowledge of tree species, their ecologies, and ways in which communities led by old growth trees, like human communities, supported one another, nourished their young and supported the life of organisms, water and soil through time. Explicit and intricate ways of narrating these relationships in the categories of thought and action in the Secwepemc language – now a severely endangered language, like most other Indigenous languages in North America – give us insights into ways of thinking of Indigenous perspectives on ecological relations in forests and landscapes.

• Nicole Fenton (nicole.fenton@uqat.ca), IRF-UQAT
• Julie Arseneault (julie.arseneault@uqat.ca), IRF-UQAT

À l’aide de clés d’identification, de documents de références variés, de loupes microscopiques et le support de bryologues, les participants de cet atelier parviendront à identifier différentes espèces de sphaignes, d’hépatiques et d’eubryophytes. 

horaire: 9h à 12h

• Nicole Fenton (nicole.fenton@uqat.ca), IRF-UQAT

Welcome to the 2022 annual conference of the Canadian Botanical Association!

After 2 years of online only conferences, we are very happy to welcome participants from across Canada, both in person and online to our beautiful UQAT campus in Rouyn-Noranda, Québec. We have planned a busy week with workshops, a public presentation on boreal plants, art expositions, keynote speakers, 2 symposia, over 90 oral and poster presentations, a mid-conference field visit to our research station and post-conference field trips. These varied activities are possible thanks to the generous support of our sponsors.

All conference participants and the general public are invited to a late afternoon and evening of activities to mark the opening of the conference! After an opening ceremony and a presentation by an Elder, we are pleased to welcome the Screaming Eagles, a drumming group from the community of lac Simon, who will offer us a performance. Three art exhibitions will also be open to the public and conference participants within the walls of UQAT. The UQAT bistro bar will be open and there will be a sale of hot dogs (meat and veg).

I invite all of our participants, particularly those here in Abitibi-Témiscamingue, to take the time to discover not only the fascinating research being presented but the just as interesting researchers behind the work. I look forward to seeing you, in person or online!

Bienvenue à la conférence annuelle de l'Association botanique canadienne, édition 2022 !

Après deux années de conférences uniquement en ligne, nous sommes très heureux d'accueillir des participant.es de partout au Canada, en personne et en ligne, sur notre magnifique campus de l'UQAT à Rouyn-Noranda, au Québec. Nous avons prévu une semaine bien remplie avec des ateliers, une conférence grande publique sur les plantes boréales, des expositions d'art, des conférencières d'honneur, deux symposiums, plus de 90 présentations orales et par affiches, une visite de notre station de recherche et des sorties post-conférence. Ces multiples activités sont rendues possible grâce à l’appui de nos nombreux partenaires et nous tenons à les remercier chaleureusement.

Tous les conférenciers et le grand public sont invités à une fin d'après-midi et soirée d'activités pour marquer l'ouverture officielle de la conférence ! Après la cérémonie d'ouverture et l'allocution par un Ainé, nous aurons le plaisir d'accueillir les Screaming Eagles, un groupe de tambours de la communauté de Lac-Simon, qui vont nous faire un spectacle. Trois expositions d'art seront également ouvertes aux conférenciers et au public dans les murs de l'UQAT. Le bar Bistro de l'UQAT sera ouvert et il y aura une vente de hot dogs (viande et végé).

J'invite tous nos participant.es, particulièrement ceux et celles ici en Abitibi-Témiscamingue, à prendre le temps de découvrir non seulement les recherches fascinantes qui seront présentées, mais aussi les chercheurs tout aussi intéressants qui se cachent derrière ces travaux. Au plaisir de vous voir, en personne ou en ligne !

• Roger Larivière (roger@naturat.ca), Nature AT

Le botaniste et mycologue passionné que je suis : professeur, auteur et consultant.
Pourquoi écrire un premier ouvrage sur la forêt boréale?
L’importance des Premiers peuples comme source d’inspiration et d’informations.
Vraiment enraciné dans le Nord et dédié au grand écosystème de la forêt boréale.
D’auteur à éditeur : les Éditions Naturat
Des ouvrages pour partager, pour vulgariser.
Un premier ouvrage vulgarisé sur les Bryophytes, en français, à paraître à l’automne.
L’avenir est dans le Nord.

Biographie
Biologiste à la retraite de l’enseignement, Roger Larivière fonde son entreprise de consultant Naturat en 2004. Après la parution d’un premier guide d’identification des plantes de la forêt boréale en 2007 (Éditions de l’Homme), l’auteur poursuit sa passion en produisant plus d’une douzaine d’ouvrages. En 2019, il fonde sa propre maison d’édition qui fera paraître à l’automne 2022 un premier guide vulgarisé en français sur les Bryophytes. Des projets sont en cours avec d’autres auteurs et la maison d’édition prend de l’expansion en ayant à coeur la vulgarisation des connaissances sur la nature.
www.naturat.ca

• Arunika Gunawardena (Arunika.Gunawardena@Dal.Ca), Dalhousie University

The lack of interest in plant biology is a continuing issue at the undergraduate level. A report from the Canadian Council of University Biology Chairs (CCUBC) curriculum task force (2019) based on a nationwide survey of biology programs, found that while 'Genetics and/or Molecular Biology' is one of the top required biology courses, ‘Plant Biology' ranked as the lowest. Even though this news is discouraging for academics who teach plant biology, it provides a timely opportunity to identify solutions to attract more students to the discipline. 

I conducted a short anonymous voluntary survey with two other faculty members among 194 undergraduate students enrolled in second or third-year plant biology courses at two universities. The survey's main findings show that 75 % of the students had taken these because they were ‘required’ as opposed to taking the courses purely out of interest, 75 % wished they had learned more basic plant biology in high school, and less than 25 % of the students were interested in pursuing a career in plant biology-related field. However, 80 % of students viewed plant biology as an interesting/exciting discipline compared to other life science disciplines. I believe that introducing plant biology at the high school level in a relevant practical way could ultimately attract more students to plant biology at the undergraduate level. 

Why do students express less interest in plants than in animals? How can we:  actively increase students' interest in plants, attract more students to plant biology, and retain students in plant biology after they graduate? In my talk, I will share some of my experiences in teaching plant biology over the last 25 years and some ideas to stimulate interest in plant biology, starting with younger kids.

• Pierre Cartier (pierre.cartier@uqat.ca), CEGEP A-T
• Toky Jeriniaina Rabearison (TokyJeriniaina.Rabearison@uqat.ca), IRF-UQAT

Le paysage abitibien se caractérise par une grande plaine glaciolacustre, composée d’argile ou de sable, au travers de laquelle émerge quelques collines couvertes de till. Ces dépôts de surface influencent à la fois le développement de la végétation et la manière dont le territoire est géré (foresterie et agriculture). Au cours de de cet atelier, les participants pourront découvrir une partie de la variété des associations sol-végétation en Abitibi et comment ces associations ont influencé le développement et l’occupation du territoire. Cet atelier aura lieu peu importe les conditions météorologiques, alors apportez un imperméable et des bottes de pluie, ainsi que des vêtements appropriés pour une journée froide et pluvieuse ou chaude et ensoleillée !

The Abitibi landscape is characterized by a large glaciolacustrine plain, composed of clay and sand, through which emerge till-covered hills. These superficial deposits influence the development of plant assemblages, as well as land management (forestry and agriculture). Through this workshop, participants will discover a variety of plant-soil associations in Abitibi and how these associations have influenced land use and development through the years. This workshop will take place regardless of the weather, so bring a rain jacket, rain boots, and clothing appropriate for either a cold rainy or a hot sunny day! 

• Laura Super (leslaura@gmail.com), University of British Columbia

How do we get the most people interested in plants and also expand our teaching and research? For this workshop we will discuss action-based research and learning using STEM and the arts (STEAM = science, technology, engineering and mathematics and the arts) to promote citizen/community science. The facilitator, Laura Super, has facilitated and participated in CBA/ABC workshops in 2021 at the last CBA/ABC joint meeting on Zoom with co-chair of the CBA/ABC Teaching Section Patrick von Aderkas. Laura has engaged undergraduates and K-12 students in botany and the phytobiome (plants, associated organisms, and environments), including with STEAM and citizen/community science approaches. STEAM provides an inclusive approach to reach more than just the traditional STEM audience; many people respond well to learning complex science concepts using the arts. Furthermore, training in drawing can help with scientific observational skills useful for learning, data collection and scientific research. Some people might also learn well through other avenues such as dance or musical storytelling, or poetry to give more examples. In the workshop we will discuss how to organize citizen/community science projects with STEAM, strategies keep them running and how to reach your goals. At the end of this workshop, participants will have skills to be able to develop and coordinate citizen/community science with STEAM projects to increase understanding and passion around botany and plant sciences.

• PARC NATIONAL D'OPÉMICAN - OPÉMICAN NATIONAL PARK, TÉMISCAMINGUE (),

Mettez votre expertise à contribution lors de ce bioblitz au Parc national Opémican au Témiscamingue. Cette toute nouvelle aire protégée pourra bénéficier du passage de botanistes dans la région par cette activité où nous tenterons de documenter la présence du plus d’espèces possibles, principalement végétales mais pas exclusivement ! Bienvenu à toute autre expertise! Ce parc, d’une beauté à couper le souffle, vous charmera. Et quoi de mieux pour se récompenser du travail accompli qu'un repas gastronomique que nous allons avoir.

Put your expertise to good use during this bioblitz at Parc national Opémican in Témiscamingue. This brand new protected area will benefit from the passage of botanists in the region through this activity where we will try to document the presence of as many species as possible, mainly plants but not exclusively! We welcome any other expertise! This breathtakingly beautiful park will charm you. And what better way to reward yourself for the work accomplished than a gourmet meal we will have.

• L'OURS ET SON MIEL - A BEAR AND HIS HONEY, AMOS (),

Venez découvrir la faune qui peuple les forêts boréales de l’Abitibi-Témiscamingue en visitant le Refuge Pageau. Cet établissement accueille les animaux sauvages dans le besoin dans une optique de réhabilitation en vue de les remettre en liberté. Lorsque la libération est impossible, le refuge offre un abri à long terme à ces animaux. La visite guidée est donc une occasion inouïe pour en apprendre davantage sur les animaux de la région,pour les observer de près et pour encourager leur rétablissement. En après-midi, la miellerie la Grande Ourse nous ouvre ses portes pour découvrir le fabuleux monde de l’apiculture grâce à un Safari apicole. Certifiée biologique, c’est avec passion que cette petite entreprise de la région tire profit des plantes maraîchères et des fleurs sauvages de la région pour produire du délicieux miel. Une dégustation d'hydromel et de gin de miel aux épices boréales sera au rendez-vous.

Discover the fauna from Abitibi-Témiscamingue’s boreal forest by visiting the Refuge Pageau. This establishment welcomes injured or in need wild animals with an aim of rehabilitation in order to release them back in the wild. When release is not possible, the shelter provides long-term shelter for these animals. The guided tour is therefore an incredible opportunity to learn more about the animals of the region, to observe them closely and to encourage their recovery.

In the afternoon, La Grande Ourse honey house opens its doors to discover the fabulous world of beekeeping thanks to a beekeeping Safari. Certified organic, it is with passion that this small business in the region takes advantage of market garden plants and wild flowers of the region to produce delicious honey. We will taste mead and honey-based gin with boreal spices.

• WILD BASKET (),

Joignez-vous au Wild Basket, une société anicinabek qui s'efforce de reconnecter les gens aux aliments traditionnels, lors d'une promenade dans leurs aires de recherche de nourriture traditionnelles, suivie d'un déjeuner léger. Il s'agit d'une excellente occasion d'en apprendre davantage sur nos plantes canadiennes familières sous un angle différent!

Join the Wild Basket, an Anishinabek corporation working to reconnect people to traditional foods, in a walk through their traditional foraging grounds, followed by a light lunch. This is an excellent opportunity learn about our familiar Canadian plants through a different lens!

• PLANTES À LEUR LIMITE - PLANTS AT THEIR LIMIT, ROUYN-NORANDA (),

Découvrez plusieurs espèces de plantes à la limite nordique de leur distribution sur les collines Kékéko. Ces collines, situées à 15 minutes de la ville de Rouyn-Noranda, sont une importante attraction pour les amateurs de plein air. Une quinzaine de sentiers sont accessibles à l’année et traversent des écosystèmes variés. Ils proposent une variété de niveau de difficultés et de longueur de randonnée. Les nombreux sentiers permettront d’explorer différents écosystèmes et de découvrir de nombreuses espèces à la limite nord de leur aire de distribution. Les plus braves pourront peut-être même se baigner dans l’un des deux lacs dans la montagne !

Discover many species at their northern limit of distribution in the Kékékos Hills. These hills, about 15 minutes outside of Rouyn-Noranda, are an important attraction for outdoor enthusiasts. About 15 trails are accessible year-round. They offer a variety of difficulty levels and hiking length. The many trails will allow you to explore different ecosystems and discover many species at the northern edge of their range. The bravest may even swim in one of the two mountain lakes.

• Rajesh Rajaselvam (Rajesh.Rajaselvam@Dal.Ca), Biology, Dalhousie University, Halifax, Nova Scotia

Being part of nature gives new dimensions to our perception of nature. Experiential learning enhances that perception by giving real-world experiences to formulate ideal conservation strategies. Since the clock of extinction is ticking fast, the message on conservation to educate the younger generation should be faster. Admiration comes through experiencing something good, thus visits to gardens and wilderness are inspirational for practical education in botany, landscaping, and plant and nature conservation. Not only do school outreach activities and undergraduate field courses in experiential learning boost conservation efforts, but also they pave way for the exchange of ideas on real conservation. The exploration of Sri Lankan national parks via multiple educational field trips made students understand the global concerns and promote awareness to make biodiversity conservation in the tropics a reality. My review concludes that garden and field visits, hands-on field activities, and resource personnel's commitments are the key to motivation for plant and biodiversity conservation in young generations.