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Harvard Forest Symposium Abstract 2020

  • Title: Network analysis of soil organic matter and microbial molecular data provides new insights on changes from long-term experimental warming at Barre Woods
  • Primary Author: Jeffrey Blanchard (University of Massachusetts - Amherst )
  • Additional Authors: Jeffrey Blanchard (University of Massachusetts - Amherst ); William Rodríguez-Reillo (University of Massachusetts - Amherst )
  • Abstract:

    William Rodriguez-Reillo, Nathan Haywood, Hanna Choi, Lauren Alteio, Stephen Callister, Rosalie K Chu, Vanessa Bailey, Lisa Bramer, Jim Tang, Serita D Frey, Jerry Melillo, Marco Keiluweit, Jeffrey L Blanchard

    Complex interactions between members of the soil food web including plants, insects, fungi, bacteria and viruses determine soil carbon dynamics and other soil biogeochemical transformations. However, we are only starting to identify the molecular processes and changes involved to the soil carbon pools in response to long-term warming. In our long-term soil warming experiment in the Barre Woods tract at Harvard Forest, a 5o C elevation in soil temperature has increased respiration rates and resulted in a net loss of soil carbon and increase nitrogen mineralization. In order to link microbial metabolism with soil biogeochemistry, we measured microbial cellular metabolism and soil organic matter chemistry using next generation nucleotide sequencing, gas chromatography and high-resolution mass spectrometry (MS). The high resolving power and measurement accuracy of masses detected with MS enabled us to identify 16,814 carbon molecules, including 58.7% with assigned molecular formula and 15.2% with hits to the KEGG database. Changes associated to lignin, hydrocarbons, and lipids reveal significant differences with the warming treatment. Annotations of the peptide fragments indicate a range of proteins that show significant differences and PPC analysis show a significant difference in heated vs control metabolites. This integrative approach provides a framework to inform soil respiration models that can be incorporated into ecosystem and biogeochemical processes.

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