Climate change in the Arctic is progressing rapidly, and much of the focus, thus far, has been on permafrost thaw and the rapid mineralization of soil organic carbon (C) by soil microorganisms. However, climate change is also increasing the abundance of woody deciduous shrubs in the Arctic, altering the vegetative biochemical landscape, which could profoundly impact the entire regional food web inclusive of terrestrial and digestive microbial communities. The quantity and quality of the carbon in these plants is a response to climatic factors, resulting in higher amounts of condensed tannins (CT) and other phenolic molecules. Condensed tannins have been reported to inhibit microbial carbon degradation by impacting microbes directly, inactivating microbial carbon degrading enzymes, or binding to nitrogen (N) and limiting available nutrients. Thus, the increase in vegetative CT in Arctic ecosystems has implications for C transformations at all trophic levels: from herbivores dependent on these plants for survival to the soil microbes responsible for degrading leaf litter. Here, we examine the response of microbial communities from arctic ruminants and soil to increased CT isolated from native Alaskan plants.
Proposer: Kelly Wrighton, The Ohio State University