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Harvard Forest Research Project 2022

  • Title: Pine encroachment effects on urban soil microbiomes
  • Principal investigator: Jennifer Bhatnagar (
  • Institution: Boston University
  • Primary contact: Jennifer Bhatnagar (
  • Team members: Lindsey Adams; Lucy Hutyra; Victoria Moscato; Nahuel Policelli; Rina Sotiropoulou; Jennifer Talbot; Pamela Templer; Corinne Vietorisz
  • Abstract:

    Understanding how soil microbial communities are related to soil and plant biogeochemical function in ecosystems can be accomplished by studying systems where soil community community composition shifts and other environmental factors remain the same. Pine tree invasions are good model systems because the community of root-associated fungi (ectomycorrhizal fungi, EMF) changes, as does soil biogeochemistry, within the same region. In the Southern Hemisphere, as pine trees that are introduced to a new landscape by humans begin to invade the surrounding native habitats, we know that they associate with different EMF communities (more Suilloid) than in the native pine range. We also know that invaded soils have unique C, N, and P amounts compared to native pine forests, plantation or surrounding native habitats. These two concomitant shifts: EMF community and soil C, N, P, suggest a relationship between EMF community composition and soil properties. However, in this system, other things change along the invasion “gradient”: plant community composition, saprotrophic communities, and potentially soil type. Many of the other environmental factors that influence EMF communities (described below) have not been measured in the field. In EMF hardwoods (oaks) stands in New England, EMF communities shift as soil biogeochemistry shifts, within the same region. EMF communities change from the forest edge (low EMF biomass, high EMF diversity) to interior (high EMF biomass, low EMF diversity). We also know that white pine is encroaching into these native hardwood forests. However, we don’t know that the effect is on EMF communities and soil biogeochemistry. The aim of this study is to compare edge effects on native oak, early successional pine, and mature pine stands from urban to rural Massachusetts, to identify how shifts in EMF communities are correlated with shifts in plant and soil biogeochemistry.