Poster #2

Changes in Soil Microbial Diversity and Community Composition Across a Pine Invasion Gradient
B REIMER , K ZHANG, K CHEN, R VILGALYS, J HOEKSEMA, J PLETT, I ANDERSON, J POWELL, A ROJAS, H LIAO
University of Florida, 201 Criser Hall PO Box 114000 Gainesville, FL 32611

Soil microbes are crucial in the establishment of forest ecosystem services. However, non-native tree introductions can disrupt microbial-mediated ecosystem functions. While invasions between hemispheres of ectomycorrhizal fungi-pine associations have been studied, bacteria communities in these soils have been neglected despite their role in nutrient cycling. We collected soils from USA native Pinus radiata forests, and from four forest types in Australia representing a conceptual gradient of pine plantation towards invasion. We profiled these bacterial communities using 16S DNA amplicon sequencing. Our results indicate a significant reduction in soil bacterial alpha diversity (Shannon Index) associated with P. radiata, in the transition from U.S native pine forests to Australian plantations and invasion front. Several bacteria families (Yersiniaceae and Enterobacteriaceae) exhibited sharp increases in abundance when transitioning from the native pine and plantation interior into the plantation edge, invasion front, and eucalyptus forests. Notably, most families changed more gradually between the latter three forest types. This suggests that forest type and management practices played important roles in the composition of bacteria communities. To inform the prediction of risks and benefits concerning soil health associated with plantations that coincide with invasion events, our ongoing study will continue to evaluate the correlation between the altered soil community and soil biogeochemistry.