Anacardium seedlings in Costa Rica
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Plant-microbe interactions are important but cryptic components of how communities and ecosystems function and respond to change. Fundamental information such as the natural history and biogeography of many microbial genotypes are unknown, and the complexity of microbial communities often results in the distillation of their functions into inelegantly simplified emergent processes. We do know that parasitic and mutualistic plant-microbe associations can change the competitive interactions among plant species, potentially influencing plant biodiversity by exerting strong control over the establishment of seedlings in a community. These plant-microbe interactions may be especially important in tropical forests, which are critical reservoirs of biodiversity increasingly threatened by changing climate and land conversion. We have found that fungi can moderate the outcomes of interspecific competition among tropical forest seedlings in direct and indirect ways. Our current work with Scott Mangan (Washington U), Stefan Schnitzerand Ching-Hong Yang (U-Wisconsin-Milwaukee) spans tropical precipitation gradients to test the relative importance of pathogens and other drivers of plant biodiversity in tropical forests over regional scales and in the context of the decreasing precipitation projected in Central America over the next decades.
NSF DEB: Collaborative Research: Pathogen-mediated negative feedbacks determine tropical tree species abundance. |
The Critical Zone (CZ) is the semi-permeable membrane on the Earth's surface that extends from bedrock to the tops of trees. Microbes drive Earth's biogeochemical cycles and play a critical role in ecosystem services including nutrient cycling, carbon stabilization, carbon flow and weathering. Despite the important role microbes play throughout the CZ profile, relatively little is known about understanding the structure of below ground communities and their functional capabilities. Ongoing projects focus on spatial variability in soil archaeal, bacterial and fungal communities across scales. Understanding linkages between microbial communities and observed biogeochemistry is assessed by coupling molecular and functional assays (i.e. rRNA surveys, metagenomic analysis and enzyme activity potential) with biogeochemical analysis to build a better predictive understanding between community structure and soil processes in a dynamic forested catchment.
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