Understanding how biodiversity is globally distributed remains a fundamental goal in ecology. Though latitudinal and climatic diversity gradients have been well established in many groups of organisms, they remain poorly documented and understood with regard to microbial symbionts, such as mycorrhizal fungi. Therefore, which factors best predict the diversity of mycorrhizal fungi along spatial gradients? In the face of rapid environmental change, it becomes important to understand aspects influencing the current diversity and distribution of mycorrhizal symbionts so we can best predict how these parameters may change in the future. Root and soil samples from various deciduous hardwoods were collected throughout the eastern United States and sequenced for mycorrhizal diversity through a multi-year citizen science project. The tree species of root samples was first identified with DNA barcodes, and then root-associated fungal communities were characterized via metabarcoding of the fungal ITS gene.
Results/Conclusions
We have generated Illumina sequence data for >300 root samples from >40 distinct locations and >10 tree species in order to investigate how the composition and diversity of mycorrhizal and non-mycorrhizal root associated fungi vary across spatial, climatic, and soil type gradients within each host tree species. In particular, we assess whether fungal community composition is strongly structured by climate, and thus sensitive to changing conditions, or determined by non-climatic, stable factors such as soil type. This information is particularly useful in considering how conservation management and restoration tools might be best applied.