Nitrogen deposition and plant species interact to influence soil carbon stabilization |
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| Authors: | Feike A Dijkstra Sarah E Hobbie Johannes M H Knops Peter B Reich |
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| Institution: | Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN 55108, USA; School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA; Department of Forest Resources, University of Minnesota, St Paul, MN 55108, USA |
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| Abstract: | Anthropogenic nitrogen (N) deposition effects on soil organic carbon (C) decomposition remain controversial, while the role of plant species composition in mediating effects of N deposition on soil organic C decomposition and long‐term soil C sequestration is virtually unknown. Here we provide evidence from a 5‐year grassland field experiment in Minnesota that under elevated atmospheric CO2 concentration (560 ppm), plant species determine whether N deposition inhibits the decomposition of soil organic matter via inter‐specific variation in root lignin concentration. Plant species producing lignin‐rich litter increased stabilization of soil C older than 5 years, but only in combination with elevated N inputs (4 g m?2 year?1). Our results suggest that N deposition will increase soil C sequestration in those ecosystems where vegetation composition and/or elevated atmospheric CO2 cause high litter lignin inputs to soils. |
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| Keywords: | Carbon isotopes elevated CO2 grassland species humification lignin nitrogen isotopes root litter soil carbon sequestration soil organic matter decomposition |
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