This week, we welcome Corrina Thomsen.
Province-wide patterns, and between-layer associations, of mycorrhizal host type within British Columbia forests
Abstract: Plant-soil feedbacks within forests can facilitate or inhibit success among neighbour seedlings depending in part on the type of mycorrhizal association; ectomycorrhizal (ECM) associations tend to yield positive, facilitative effects whereas arbuscular mycorrhizal (AM) associations tend to elicit negative, antagonistic effects. Given these potential feedbacks, details about the fine-scale prevalence and distribution of MF hosts and their association types, particularly within each forest layer, could improve our understanding of recruitment dynamics and diversity patterns within forests. Using forest survey data from more than 25,000 plots distributed throughout British Columbia (BC), we first show how the proportion of different mycorrhizal types varies between the herbaceous layer and the canopy, and the encounter probability between types across BC. We then quantify the strength of the association between the proportion of AM and ECM-compatible host cover in the canopy with the same proportion in the sub-canopy and herbaceous layers. Our findings reveal significant negative associations between AM hosts and neutral associations between ECM hosts, but also underscore how encounter probabilities varies enormously among forest types.