• Biogeochemistry of Arctic Hillslopes
    • Tamara Harms (Assistant Professor, Institute of Arctic Biology)
    • April 06, 2018

Abstract

Hydrologic flowpaths may propagate biogeochemical signals among connected ecosystems or attenuate signals due to reactions or retention occurring during transport. In the Arctic, increased nitrogen (N) availability occurs when terrestrial tundra is warmed, and a similar release of phosphorus (P) may also occur, but the fates of these newly released nutrients remain unclear. Nutrients may be passively transported downslope in flowing water, or retained when flowpaths intercept N-limited ecosystems. We examined transport and retention of N and P within water tracks, abundant features that drain hillslopes of upland tundra, and connect soils to receiving aquatic ecosystems. Using tracer experiments, we quantified strong capacity to retain P, in contrast with a pattern of N export. Thus, water tracks contribute to propagating the terrestrial signal of warming across landscapes by transporting N. The consequences of this pattern may include increasing delivery of N to coasts as climate becomes warmer and wetter.


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Meeting ID: 451-204-998


 

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