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Harvard Forest Symposium Abstract 2018

  • Title: Exploiting the influence of diversity loss for carbon use efficiency in soils
  • Primary Author: Luiz Domeignoz Horta (University of Massachusetts - Amherst )
  • Additional Authors: Kristen DeAngelis (University of Massachusetts - Amherst ); Serita Frey (University of New Hampshire - Main Campus); Jerry Melillo (Marine Biological Laboratory); Grace Pold (University of Massachusetts Amherst)
  • Abstract:

    Soils retain the largest organic carbon pool in the terrestrial biosphere and represent an important source of carbon dioxide (CO2) to the atmosphere. Microbial carbon use efficiency – or the fraction of C taken up by a cell that is converted to biomass – is a central determinant of how much of this carbon is able to be retained in soil. CUE has been proposed to vary with both biotic and abiotic conditions; therefore, understanding how this pivotal variable in the C cycle will respond to the dually changing climate and biodiversity is of upmost importance. The present study addresses how diversity loss combined with rising temperatures will impact CUE and the consequences for soil CO2 fluxes. Here we extracted communities exposed to chronic warming and not exposed to warming (Harvard Forest – Prospect Hill site), manipulated the diversity of these communities and will evaluate how they perform CUE under different abiotic conditions (two temperatures 15℃ and 25℃ and two moisture levels 30% and 60% of water holding capacity). We hypothesize that: 1) chronic warming selects for a microbial community with higher CUE under warmer temperatures compared to soils not exposed to warming (Frey et al., 2013); 2) different communities will have distinct CUE and respond differently to temperature/moisture treatments; and 3) more diverse communities have higher CUE due to synergistic effects between species. This ongoing work links biodiversity and ecosystem functioning in the context of soil organic matter retention. It also promises to bring new knowledge on how two major global concerns, which are global warming and biodiversity loss, will interact and possibly feedback each other.

  • Research Category: Soil Carbon and Nitrogen Dynamics