With increasing temperature and changing precipitation regimens due to climate change, temperate forest trees will have to adapt to new climatic conditions or shift ranges to track historic climates. Root associated microbes may aid tree survival in temperate forests. Specifically, different mycorrhizal fungal symbioses associated with forest trees may impact tree seedling success when facing a changing climate. We tested whether microbial communities sourced from warmer and drier climates influence tree seedling tolerance of drought. Specifically, we examined arbuscular mycorrhizae (AM) and ectomycorrhizae (EM) in mediating seedling growth of tree species with either northern or southern range edges. We used a greenhouse experiment to simulate current and predicted temperatures and precipitation on tree seedlings inoculated with microbial communities sourced from 12 locations along a temperature and precipitation gradient.
Results/Conclusions
Our results show that EM tree species undergoing a simulated drought treatment inoculated with microbes from drier locations had increased seedling survival compared to EM tree species inoculated with microbial communities sourced from wetter locations. We characterized the microbial populations using 16S and ITS metabarcoding to investigate how AM and EM species associate with different microbial taxa under different climate conditions. These results reveal the differences EM and AM associating trees may have in their response to climate change. Greater functional diversity of EM associated trees may lead to EM trees having an advantage when faced with a changing climate.