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Harvard Forest Research Project 2022

  • Title: Exploring mechanisms of plant-microbiome functional interactions in S. purpurea
  • Principal investigator: Benjamin Baiser (
  • Institution: University of Florida
  • Primary contact: Sydne Record (
  • Team members: Benjamin Baiser
  • Abstract:

    Microbiomes are not static, but change in composition and function through time and space. These changes have significant consequences for host fitness and the functioning of entire ecosystems. Uncovering rules that govern microbiome functional variation across time and space is essential for understanding microbiome-host and microbiome-ecosystem relationships. One of the fundamental processes operating within ecosystems is succession: temporal change in species composition where early colonizers give way to mid and late successional species. Successional change in composition has implications for community functioning which subsequently for the health of organisms and of our planet's ecosystems, these have not been well-documented with regard to microbes, and have not been incorporated into ecological theory. Further, our lack of understanding about microbiome functional change through time has significance for engineering synthetic microbiomes for applications in agriculture and human health.

    Recently, microbiologists have begun to integrate novel trait-based approaches with long standing ecological theory on community assembly to better understand the assembly and function of microbial assemblages. One such approach, adapted from classic theory on plant communities, explores the role of resource availability and stress in driving the life history strategies of microbial communities. This framework conceptualizes the functional space in which microbial assemblages exist as a triangle where each corner is represented by a life history strategy as defined by functional traits. These life history strategies include the high yield strategy (Y), resource acquisition category (A), and the stress tolerator strategy (S). Based on life history trade-offs, each strategy is successful under varying conditions of resource availability and stress. Drivers of community composition and function across a vast range of microbiomes (and microbial systems) can be characterized in terms of their effect on either stress and/or resource availability. Thus, the Y-A-S framework facilitates a search for general rules for how microbial assemblages and their functions respond to various conditions across space and time.

    Although the Y-A-S framework holds strong potential for uncovering general rules of microbiomes, it has yet to be extended over successional time, and linked to actual community functioning and the influence on host health. In our proposal, we will employ and extend this novel framework by applying it to microbiomes over successional time scales and further tying it directly to microbiome hosts in the model system, the pitcher plant Sarracenia purpurea.