SYMP 12-3 - Forecasting the forest mycobiome

Thursday, August 15, 2019: 9:00 AM
Ballroom D, Kentucky International Convention Center
Colin Averill, Environmental Systems Sciences, ETH Zürich, Zürich, Switzerland, Jennifer M. Bhatnagar, Department of Biology, Boston University, Boston, MA, Michael C. Dietze, Earth and Environment, Boston University, Boston, MA, Ann M. Raiho, Department of Biological Sciences, University of Notre Dame, Notre Dame, IN and Zoey R. Werbin, Biology, Boston University, Boston, MA
Background/Question/Methods

New approaches to measuring the identity and distribution of soil microorganisms have revolutionized how we understand forests. Global soil microbiome surveys have laid the groundwork for understanding whether or not microbiome composition merely follows plant community patterns, or has its own unique biogeography. The ability to link tree species identity to distinct root-associated microbial (i.e. fungal) communities places a high level constraint on the composition of the forest soil microbiome. However, in a world experiencing rapid multi-factor global change, we must not only understand where microbes are, but how we expect these communities to change in time. In this presentation, we show an unprecedented ability to forecast the future of forest fungal microbiomes (mycobiomes) by combining forest inventory data, paleo-ecological records, and repeated measures of soil microbial communities across the National Ecological Observatory Network (NEON). We address the role of environmental filtering and priority effects in determining the distribution and future of forest soil fungi.

Results/Conclusions

Both historic forest composition and environmental drivers are important for predicting contemporary forest mycorrhizal distributions. Furthermore, historic composition interacts with environmental change, revealing signatures of priority effects and community resistance to a changing environment. For instance, looking in deep time, comparing pre-settlement and contemporary forests in the Midwestern United States, the relative abundance of arbuscular vs. ectomycorrhizal forests has changed dramatically. N deposition is linked to a temporal shift from ectomycorrhizal to arbuscular mycorrhizal forests, however, the shift is less likely if a forest historically contained more ectomycorrhizal trees. Analogous results are found when analyzing contemporary growth and recruitment data of forests within this region. Diving deeper, we test for signatures of fungal community resistance within ecto- and arbuscular mycorrhizal forests using molecular data collected by the National Ecological Observatory Network. Taken together, these findings suggest that forecasting the forest microbiome requires not only understanding environmental filtering and environmental change, but also community interactions that may determine priority effects and fungal community resistance to global change forcing.