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Harvard Forest Symposium Abstract 2017

  • Title: Tree species and diversity effects on soil respiration across spatial scales
  • Primary Author: Fiona Jevon (Dartmouth College)
  • Additional Authors: Matthew Ayres (Dartmouth College); Jaclyn Matthes (Wellesley College)
  • Abstract:

    In Northeast temperate forests, individual trees alter the soil beneath them through phenological effects on microclimate, differences in root exudation and mycorrhizae, and litter inputs. In experimental grasslands, higher plant diversity increases both aboveground productivity and total soil respiration due to niche partitioning belowground. It remains unclear whether links between diversity and belowground carbon cycling exist in tree species mixtures in unmanaged forests. This study asks whether tree species identity influences soil respiration through microclimate, mycorrhizal association, or litter characteristics; and what the relationship is between soil respiration and tree species identity and diversity at multiple spatial scales.
    We found that soil respiration in plots surrounded with three trees of the same species differ from each other and these differences seem to be due to a combination of pathways. We also found that tree identity and diversity operate differently depending on the spatial scale. Plots defined as triangles of three trees of different species exhibit soil respiration rates that are intermediate to the rates found in triangles of three trees of the component single species. However, soil respiration is positively related to the species richness of trees at a larger spatial scale (10x10m). These results highlight the importance of considering vegetation patterns at several spatial scales when addressing mechanisms by which tree species diversity influences ecosystem processes.

  • Research Category: Soil Carbon and Nitrogen Dynamics; Biodiversity Studies