{"id":{"repo_id":"sherbrooke","oai_identifier":"oai:usherbrooke.scholaris.ca:11143/23919"},"canonical_url":"https://search.dev.ndltd.org/etd/sherbrooke/oai:usherbrooke.scholaris.ca:11143/23919","repository":{"repo_id":"sherbrooke","name":"Université de Sherbrooke","base_url":"https://usherbrooke.scholaris.ca/server/oai/request"},"display":{"title":"The relationship between dominant forest mycorrhizal type and the belowground mycobiome of the sugar maple and eastern hemlock","abstract":"Climate change is imposing significant pressures on forest ecosystems, with many tree species projected to migrate towards the poles in response to changing temperature and precipitation regimes. Those who do not migrate will have to contend with these altered regimes, as well as changing surrounding forest communities. However, in both instances, biotic (e.g., mycorrhizal regimes and fungal communities) and abiotic conditions (e.g., soil chemistry) may act as important filters that potentially impede these migration and adaptation scenarios. Given that dominant forest mycorrhizal types are known to have strong impacts on forests’ belowground biogeochemistry and non-mycorrhizal microbial communities, their roles in this process should be more explicitly considered. The objectives of this project were therefore to determine the impact of dominant forest mycorrhizal types on soil and root (1) fungal diversity and community composition, (2) taxonomic and functional groupings, as well as (3) arbuscular mycorrhizal colonization along four gradients of forest mycorrhizal types. To do this, 435 seedlings of the sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) were identified, measured and harvested across four sites, Mont-Écho, Mégantic National Park, Lac-des-Plages, and the Station de biology des Laurentides. I characterized the root and soil fungal communities of maple and hemlock via amplicon sequencing, as well as root fungal colonization via microscopy. In addition, I characterized the edaphic parameters and the surrounding understory plant communities of seedlings. The results showed that forest mycorrhizal type had important associations with root fungal colonization by both arbuscular mycorrhizal and dark septate endophyte fungi, but I could not detect a significant impact on fungal diversity and community composition. However, I found evidence of dual-mycorrhization in the otherwise ectomycorrhizal eastern hemlock, which had only been previously reported in greenhouse studies. Conversely, dominant mycorrhizal type was found to strongly associate with the relative abundances of saprotrophic and ectomycorrhizal functional groups but showed no discernible association with fungal pathogens. Soil pH and calcium were significantly associated with dominant mycorrhizal types, while other soil variables showed no association. Taken together, these results suggest that dominant mycorrhizal types can have strong associations with certain fungal functional groups, important aspects of soil chemistry, and root colonization in both the eastern hemlock and sugar maple, which will be important factors to consider in the management of these species as they migrate into new forest regimes or see the composition of their resident forests change around them.","abstract_html":"Climate change is imposing significant pressures on forest ecosystems, with many tree species projected to migrate towards the poles in response to changing temperature and precipitation regimes. Those who do not migrate will have to contend with these altered regimes, as well as changing surrounding forest communities. However, in both instances, biotic (e.g., mycorrhizal regimes and fungal communities) and abiotic conditions (e.g., soil chemistry) may act as important filters that potentially impede these migration and adaptation scenarios. Given that dominant forest mycorrhizal types are known to have strong impacts on forests’ belowground biogeochemistry and non-mycorrhizal microbial communities, their roles in this process should be more explicitly considered. The objectives of this project were therefore to determine the impact of dominant forest mycorrhizal types on soil and root (1) fungal diversity and community composition, (2) taxonomic and functional groupings, as well as (3) arbuscular mycorrhizal colonization along four gradients of forest mycorrhizal types. To do this, 435 seedlings of the sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) were identified, measured and harvested across four sites, Mont-Écho, Mégantic National Park, Lac-des-Plages, and the Station de biology des Laurentides. I characterized the root and soil fungal communities of maple and hemlock via amplicon sequencing, as well as root fungal colonization via microscopy. In addition, I characterized the edaphic parameters and the surrounding understory plant communities of seedlings. The results showed that forest mycorrhizal type had important associations with root fungal colonization by both arbuscular mycorrhizal and dark septate endophyte fungi, but I could not detect a significant impact on fungal diversity and community composition. However, I found evidence of dual-mycorrhization in the otherwise ectomycorrhizal eastern hemlock, which had only been previously reported in greenhouse studies. Conversely, dominant mycorrhizal type was found to strongly associate with the relative abundances of saprotrophic and ectomycorrhizal functional groups but showed no discernible association with fungal pathogens. Soil pH and calcium were significantly associated with dominant mycorrhizal types, while other soil variables showed no association. Taken together, these results suggest that dominant mycorrhizal types can have strong associations with certain fungal functional groups, important aspects of soil chemistry, and root colonization in both the eastern hemlock and sugar maple, which will be important factors to consider in the management of these species as they migrate into new forest regimes or see the composition of their resident forests change around them.","abstract_has_math":false,"creators":["Beauregard, Jacob"],"institution":"Université de Sherbrooke","degree_name":"M. Sc.","degree_level":"Maîtrise","degree_discipline":"Biologie","degree_department":null,"school":null,"contributors":[],"advisors":["Laforest-Lapointe, Isabelle","Chagnon, Pierre-Luc"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026","date_published":"2026","updated_at":"2026-07-27T21:07:37Z","subjects":["Sugar maple","Eastern hemlock","Mycorrhizae","Mycorrhizal gradients","Dark septate endophytes","Climate change","Fungal communities","Tree-fungal interactions","Érable à sucre","Pruche de l'Est","Mycorhizes","Gradients mycorhiziens","Endophytes septés foncés","Changements climatiques","Communautés fongiques","Interactions arbre-champignon"],"languages":["en"],"rights":[],"rights_urls":["http://creativecommons.org/licenses/by/4.0/"],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.71892/11143/1375"],"render_values":[{"text":"https://doi.org/10.71892/11143/1375","href":"https://doi.org/10.71892/11143/1375","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/11143/23919","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Laforest-Lapointe, Isabelle","Chagnon, Pierre-Luc"]},{"key":"dc:creator","label":"Author","values":["Beauregard, Jacob"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-01-23T15:43:44Z"]},{"key":"dc:date.issued","label":"Date","values":["2026"]},{"key":"dc:publisher","label":"Institution","values":["Université de Sherbrooke"]},{"key":"dc:type","label":"Dc Type","values":["Mémoire de maîtrise"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biologie"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Maîtrise"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M. 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Those who do not migrate will have to contend with these altered regimes, as well as changing surrounding forest communities. However, in both instances, biotic (e.g., mycorrhizal regimes and fungal communities) and abiotic conditions (e.g., soil chemistry) may act as important filters that potentially impede these migration and adaptation scenarios. Given that dominant forest mycorrhizal types are known to have strong impacts on forests’ belowground biogeochemistry and non-mycorrhizal microbial communities, their roles in this process should be more explicitly considered. The objectives of this project were therefore to determine the impact of dominant forest mycorrhizal types on soil and root (1) fungal diversity and community composition, (2) taxonomic and functional groupings, as well as (3) arbuscular mycorrhizal colonization along four gradients of forest mycorrhizal types. To do this, 435 seedlings of the sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) were identified, measured and harvested across four sites, Mont-Écho, Mégantic National Park, Lac-des-Plages, and the Station de biology des Laurentides. I characterized the root and soil fungal communities of maple and hemlock via amplicon sequencing, as well as root fungal colonization via microscopy. In addition, I characterized the edaphic parameters and the surrounding understory plant communities of seedlings. The results showed that forest mycorrhizal type had important associations with root fungal colonization by both arbuscular mycorrhizal and dark septate endophyte fungi, but I could not detect a significant impact on fungal diversity and community composition. However, I found evidence of dual-mycorrhization in the otherwise ectomycorrhizal eastern hemlock, which had only been previously reported in greenhouse studies. Conversely, dominant mycorrhizal type was found to strongly associate with the relative abundances of saprotrophic and ectomycorrhizal functional groups but showed no discernible association with fungal pathogens. Soil pH and calcium were significantly associated with dominant mycorrhizal types, while other soil variables showed no association. Taken together, these results suggest that dominant mycorrhizal types can have strong associations with certain fungal functional groups, important aspects of soil chemistry, and root colonization in both the eastern hemlock and sugar maple, which will be important factors to consider in the management of these species as they migrate into new forest regimes or see the composition of their resident forests change around them.","Les changements climatiques exercent d'importantes pressions sur les écosystèmes forestiers, alors qu’il est prévu que de nombreuses espèces d'arbres migrent vers les pôles en réponse aux changements de régime de température et de précipitations. Celles qui ne migrent pas devront faire face à ces régimes modifiés, ainsi qu'au changement des communautés forestières environnantes. Cependant, dans les deux cas, les conditions biotiques (par exemple, régimes mycorhiziens et communautés fongiques) et abiotiques (par exemple, la chimie des sols) peuvent agir comme des filtres importants qui pourraient entraver ces scénarios de migration et d'adaptation. Étant donné que les types mycorhiziens dominants des forêts sont connus pour avoir de forts impacts sur la biogéochimie souterraine et les communautés microbiennes non mycorhiziennes de la forêt, leur rôle dans ce processus devrait être plus explicitement considéré. Les objectifs de ce projet étaient donc de déterminer l’association entre des types de mycorhizes forestiers dominants et le sol et les racines sur (1) la diversité fongique et la composition des communautés, (2) les regroupements taxonomiques et fonctionnels, ainsi que (3) la colonisation mycorhizienne (uniquement les racines) le long de quatre gradients de types mycorhiziens forestiers. Pour ce faire, 435 semis d'érable à sucre (Acer saccharum) et de pruche de l'Est (Tsuga canadensis) ont été identifiés, mesurés et récoltés sur quatre sites : Mont-Écho (Sutton), le parc national du Mont-Mégantic, Lac-des-Plages, et la Station de biologie des Laurentides. J'ai caractérisé les communautés fongiques racinaires et du sol de l'érable et de la pruche par séquençage par amplicon, ainsi que la colonisation fongique racinaire par microscopie. De plus, j'ai caractérisé les paramètres édaphiques et les communautés végétales environnantes du sousbois des semis. Les résultats ont montré que le type mycorhizien forestier avait des impacts importants sur la colonisation fongique des racines par les champignons mycorhiziens arbusculaires et les endophytes septés sombres, mais je n'ai pas pu détecter d'impact significatif sur la diversité fongique et la composition des communautés. Cependant, j'ai trouvé des preuves de double mycorhization chez la pruche de l’Est autrement ectomycorhizienne, qui n'avait été rapportée auparavant que dans des études en serre. Inversement, le type mycorhizien dominant a été observé comme ayant un impact fort sur les groupes fonctionnels saprotrophes et ectomycorhiziens, mais n'a montré aucun impact discernable sur les pathogènes fongiques. Le pH du sol et le calcium étaient significativement associés aux types mycorhiziens dominants, tandis que d'autres variables du sol n’y répondaient pas. Ensemble, ces résultats suggèrent que les types mycorhiziens dominants peuvent avoir de forts impacts sur certains groupes fonctionnels fongiques, des aspects importants de la chimie des sols et la colonisation racinaire tant chez la pruche de l'Est que chez l'érable à sucre, des facteurs importants à considérer dans la gestion de ces espèces alors qu'elles migrent vers de nouveaux régimes forestiers ou voient la composition de leurs forêts résidentes changer autour d'elles."]},{"key":"dc:title","label":"Title","values":["The relationship between dominant forest mycorrhizal type and the belowground mycobiome of the sugar maple and eastern hemlock"]}]}],"canonical_facts":{"dc:contributor.advisor":["Laforest-Lapointe, Isabelle","Chagnon, Pierre-Luc"],"dc:creator":["Beauregard, Jacob"],"dc:date.accessioned":["2026-01-23T15:43:44Z"],"dc:date.issued":["2026"],"dc:description.abstract":["Climate change is imposing significant pressures on forest ecosystems, with many tree species projected to migrate towards the poles in response to changing temperature and precipitation regimes. Those who do not migrate will have to contend with these altered regimes, as well as changing surrounding forest communities. However, in both instances, biotic (e.g., mycorrhizal regimes and fungal communities) and abiotic conditions (e.g., soil chemistry) may act as important filters that potentially impede these migration and adaptation scenarios. Given that dominant forest mycorrhizal types are known to have strong impacts on forests’ belowground biogeochemistry and non-mycorrhizal microbial communities, their roles in this process should be more explicitly considered. The objectives of this project were therefore to determine the impact of dominant forest mycorrhizal types on soil and root (1) fungal diversity and community composition, (2) taxonomic and functional groupings, as well as (3) arbuscular mycorrhizal colonization along four gradients of forest mycorrhizal types. To do this, 435 seedlings of the sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) were identified, measured and harvested across four sites, Mont-Écho, Mégantic National Park, Lac-des-Plages, and the Station de biology des Laurentides. I characterized the root and soil fungal communities of maple and hemlock via amplicon sequencing, as well as root fungal colonization via microscopy. In addition, I characterized the edaphic parameters and the surrounding understory plant communities of seedlings. The results showed that forest mycorrhizal type had important associations with root fungal colonization by both arbuscular mycorrhizal and dark septate endophyte fungi, but I could not detect a significant impact on fungal diversity and community composition. However, I found evidence of dual-mycorrhization in the otherwise ectomycorrhizal eastern hemlock, which had only been previously reported in greenhouse studies. Conversely, dominant mycorrhizal type was found to strongly associate with the relative abundances of saprotrophic and ectomycorrhizal functional groups but showed no discernible association with fungal pathogens. Soil pH and calcium were significantly associated with dominant mycorrhizal types, while other soil variables showed no association. Taken together, these results suggest that dominant mycorrhizal types can have strong associations with certain fungal functional groups, important aspects of soil chemistry, and root colonization in both the eastern hemlock and sugar maple, which will be important factors to consider in the management of these species as they migrate into new forest regimes or see the composition of their resident forests change around them.","Les changements climatiques exercent d'importantes pressions sur les écosystèmes forestiers, alors qu’il est prévu que de nombreuses espèces d'arbres migrent vers les pôles en réponse aux changements de régime de température et de précipitations. Celles qui ne migrent pas devront faire face à ces régimes modifiés, ainsi qu'au changement des communautés forestières environnantes. Cependant, dans les deux cas, les conditions biotiques (par exemple, régimes mycorhiziens et communautés fongiques) et abiotiques (par exemple, la chimie des sols) peuvent agir comme des filtres importants qui pourraient entraver ces scénarios de migration et d'adaptation. Étant donné que les types mycorhiziens dominants des forêts sont connus pour avoir de forts impacts sur la biogéochimie souterraine et les communautés microbiennes non mycorhiziennes de la forêt, leur rôle dans ce processus devrait être plus explicitement considéré. Les objectifs de ce projet étaient donc de déterminer l’association entre des types de mycorhizes forestiers dominants et le sol et les racines sur (1) la diversité fongique et la composition des communautés, (2) les regroupements taxonomiques et fonctionnels, ainsi que (3) la colonisation mycorhizienne (uniquement les racines) le long de quatre gradients de types mycorhiziens forestiers. Pour ce faire, 435 semis d'érable à sucre (Acer saccharum) et de pruche de l'Est (Tsuga canadensis) ont été identifiés, mesurés et récoltés sur quatre sites : Mont-Écho (Sutton), le parc national du Mont-Mégantic, Lac-des-Plages, et la Station de biologie des Laurentides. J'ai caractérisé les communautés fongiques racinaires et du sol de l'érable et de la pruche par séquençage par amplicon, ainsi que la colonisation fongique racinaire par microscopie. De plus, j'ai caractérisé les paramètres édaphiques et les communautés végétales environnantes du sousbois des semis. Les résultats ont montré que le type mycorhizien forestier avait des impacts importants sur la colonisation fongique des racines par les champignons mycorhiziens arbusculaires et les endophytes septés sombres, mais je n'ai pas pu détecter d'impact significatif sur la diversité fongique et la composition des communautés. Cependant, j'ai trouvé des preuves de double mycorhization chez la pruche de l’Est autrement ectomycorhizienne, qui n'avait été rapportée auparavant que dans des études en serre. Inversement, le type mycorhizien dominant a été observé comme ayant un impact fort sur les groupes fonctionnels saprotrophes et ectomycorhiziens, mais n'a montré aucun impact discernable sur les pathogènes fongiques. Le pH du sol et le calcium étaient significativement associés aux types mycorhiziens dominants, tandis que d'autres variables du sol n’y répondaient pas. Ensemble, ces résultats suggèrent que les types mycorhiziens dominants peuvent avoir de forts impacts sur certains groupes fonctionnels fongiques, des aspects importants de la chimie des sols et la colonisation racinaire tant chez la pruche de l'Est que chez l'érable à sucre, des facteurs importants à considérer dans la gestion de ces espèces alors qu'elles migrent vers de nouveaux régimes forestiers ou voient la composition de leurs forêts résidentes changer autour d'elles."],"dc:identifier.doi":["https://doi.org/10.71892/11143/1375"],"dc:identifier.uri":["https://hdl.handle.net/11143/23919"],"dc:language.iso":["en"],"dc:publisher":["Université de Sherbrooke"],"dc:rights.uri":["http://creativecommons.org/licenses/by/4.0/"],"dc:subject":["Sugar maple","Eastern hemlock","Mycorrhizae","Mycorrhizal gradients","Dark septate endophytes","Climate change","Fungal communities","Tree-fungal interactions","Érable à sucre","Pruche de l'Est","Mycorhizes","Gradients mycorhiziens","Endophytes septés foncés","Changements climatiques","Communautés fongiques","Interactions arbre-champignon"],"dc:title":["The relationship between dominant forest mycorrhizal type and the belowground mycobiome of the sugar maple and eastern hemlock"],"dc:type":["Mémoire de maîtrise"],"thesis:degree_discipline":["Biologie"],"thesis:degree_level":["Maîtrise"],"thesis:degree_name":["M. Sc."],"thesis:institution_name":["Université de Sherbrooke"]},"updated_at":"2026-07-27T21:07:37Z"}