I am a microbial ecologist, interested in spatial and temporal ecology of microbial communities as well as microbe-microbe interactions. From early 2022, I am a postdoc in the lab of Isabelle Laforest-Lapointe (Sherbrooke University, Canada). I am eager to understand the distribution and temporal dynamics of diverse microbial communities (i.e., fungi and bacteria) across neighborhoods with different socio-economic status in several cities of Quebec. Furthermore, from a more theoretical point of view, I explore how modern ecological theory that has been widely applied to macroorganisms can be used to predict the dynamics of microorganisms.
The interplay of biotic and abiotic factors shapes tree root endophyte communities and seedling growth
M. FATICOV*, J. CHAMARD*, F. G. BLANCHET, P-L. CHAGNON AND I. LAFOREST-LAPOINTE
Département de biologie, Université de Sherbrooke, Sherbrooke (J1K 2R1), QC, Canada (*equal contributions)
Root endophytic microbes can alleviate plant abiotic stresses, thus potentially supporting adaptation to a changing climate during plant range shifts. While climate change is extending plant fundamental niches northward, the distribution and colonization of mutualists (e.g., arbuscular mycorrhizal fungi) and pathogens may constrain plant growth and regeneration. Yet, the degree to which biotic and abiotic factors impact plant performance and associated microbial communities at the edge of their distribution remains unclear. Here, we used root microscopy analysis, coupled with short marker sequencing, to study bacterial, fungal, and mycorrhizal root endophytic communities from sugar maple seedlings distributed across two temperate-to-boreal elevational gradients in southern Québec, Canada. Our findings demonstrate that soil pH, soil Ca, and distance to sugar maple trees are key drivers of root endophyte microbial communities, overshadowing the influence of elevation. Interestingly, changes in root fungal community composition mediated an indirect effect of soil pH on seedling growth, a pattern consistent at both sites. Overall, our findings highlight a complex role of biotic and abiotic factors in shaping tree-microbe interactions, which are in turn impacting seedling growth. These findings have important implications for tree range expansion in response to shifting climatic conditions.