| Abstract: | Symbiotic N2-fixing tree species can accelerate ecosystem N dynamics through decomposition via direct pathways by producing readily decomposed leaf litter and increasing N supply to decomposers, as well as via indirect pathways by increasing tissue and detrital N in non-fixing vegetation. To evaluate the relative importance of these pathways, we compared three-year decomposition and N dynamics of N2-fixing red alder leaf litter (2.34 %N) to both low-N (0.68 %N) and high-N (1.21 %N) litter of non-fixing Douglas-fir, and decomposed each litter source in four forests dominated by either red alder or Douglas-fir. We also used experimental N fertilization of decomposition plots to assess elevated N availability as a potential mechanism of N2-fixer effects on litter mass loss and N dynamics. Direct effects of N2-fixing red alder on decomposition occurred primarily as faster N release from red alder than Douglas-fir litter, but direct increases in N supply to decomposers via fertilization did not stimulate decomposition of any litter. Fixed N indirectly influenced detrital dynamics by increasing Douglas-fir tissue and litter N concentrations, which accelerated litter N release without accelerating mass loss. By increasing soil N, tissue N, and the rate of N release from litter of non-fixers, we conclude that N2-fixing vegetation can indirectly foster plant-soil feedbacks that contribute to the persistence of elevated N availability in terrestrial ecosystems. |
| Genre: | Article |
| ProdID: | 70040478 |
| Citation Author: | Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E. |
| Citation Contributing Office: | Forest and Rangeland Ecosystem Science Center |
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| Citation End Page: | 1193 |
| Citation Issue: | 7 |
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| Citation Language: | English |
| Citation Larger Work Title: | Ecosystems |
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| Citation Number Of Pages: | 11 |
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| Citation Phsyical Description: | 12 p. |
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| Citation Publisher: | Springer |
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| Citation Search Results Text: | N2-fixing red alder indirectly accelerates ecosystem nitrogen cycling; 2012; Article; Journal; Ecosystems; Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E. |
| Citation Start Page: | 1182 |
| Citation Volume: | 15 |
| Citation Year: | 2012 |
| Type: | citation/reference |
| Text: | N2-fixing red alder indirectly accelerates ecosystem nitrogen cycling; 2012; Article; Journal; Ecosystems; Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1007/s10021-012-9579-2 |
| Date Other: | Thu, 25 Oct 2012 14:25 -0500 |
| Publisher: | Springer |
