You are here

Harvard Forest >

Harvard Forest Symposium Abstract 2014

  • Title: Effects of 11 Years of Soil Warming on Carbon Storage and Nitrogen Cycling in a Deciduous Forest Ecosystem: the Barre Woods Study
  • Primary Author: William Werner (Marine Biological Laboratory)
  • Abstract:

    The Barre Woods experiment was designed to explore the effects of soil warming on carbon and nitrogen interactions at the ecosystem level, with a particular focus on how an enhanced nitrogen cycle in response to warming affects carbon storage in vegetation.

    Over the first 10 years of the study, warming stimulated the decomposition of soil organic matter and the loss of soil carbon as carbon dioxide to the atmosphere. While soil warming has resulted in a cumulative net loss of carbon relative to a control area over the ten-year study, increased plant carbon storage has compensated for about 60% soil carbon losses over the course of the experiment to date. Warming has also increased nitrogen availability to plants by stimulating nitrogen mineralization rates, accounting for the increased plant carbon accumulation. (Melillo et al. 2011. PNAS 108(23): 9508-9512). Since the start of the experiment, we have observed a 45% average annual increase in net nitrogen mineralized and a 25% increase in nitrification rates (Butler et al. 2012. Oecologia 168:819-828. ).

    In the 11th year of the study, we continued to observe soil carbon losses in response to warming. However, for the first time we observed no increase in carbon storage in the trees in response to soil warming. We are now exploring the mechanisms responsible for this new response.

  • Research Category: Forest-Atmosphere Exchange, Large Experiments and Permanent Plot Studies, Soil Carbon and Nitrogen Dynamics