Extreme storms and changes in particulate and dissolved organic carbon in runoff: Entering uncharted waters?

Authors

  • Gurbir Singh Dhillon,

    1. Plant and Soil Sciences Department, University of Delaware, Newark, Delaware, USA
    2. Soil Sciences Department, University of Saskatoon, Saskatchewan, Canada
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  • Shreeram Inamdar

    Corresponding author
    1. Plant and Soil Sciences Department, University of Delaware, Newark, Delaware, USA
    • Corresponding author: S. Inamdar, 152 Townsend Hall, 531 S. College Avenue, University of Delaware, Newark, DE 19716, USA. (Inamdar@udel.edu)

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Abstract

[1] We determined the runoff exports of particulate (POC) and dissolved organic carbon (DOC) from a 12 ha forested catchment which received more than 14 storm events in a 16-month period and three extreme events associated with hurricanes. While POC and DOC exports for the small events were comparable, POC exports for the hurricane-associated events were six to eight times the DOC values. Hurricane Irene alone contributed to 56% (21.2 kg C ha–1) and 19% (3.3 kg C ha–1) of the 2011 exports of POC and DOC, respectively. A precipitation threshold beyond which POC fluxes rapidly outpaced the DOC values was also identified. Our study suggests that large, high-intensity storm events that are predicted to increase under future climate-change scenarios will dramatically alter the runoff C regime by enhancing the POC inputs to aquatic ecosystems. Such shift in C forms could have important consequences for aquatic biota, atmospheric C cycling, and ecosystem and human health.

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