|
|||||
|
|
Regional Assessment of N Saturation using Foliar and Root \varvec {\delta}^{\bf 15}{\bf N} |
|
| Authors: | L H Pardo P H Templer C L Goodale S Duke P M Groffman M B Adams P Boeckx J Boggs J Campbell B Colman J Compton B Emmett P Gundersen J Kjønaas G Lovett M Mack A Magill M Mbila M J Mitchell G McGee S McNulty K Nadelhoffer S Ollinger D Ross H Rueth L Rustad P Schaberg S Schiff P Schleppi J Spoelstra W Wessel |
| Institution: | 1. Northeastern Research Station, USDA Forest Service, P.O. Box 968, Burlington, VT, 05402, USA 2. Department of Biology, Boston University, Boston, MA, 02215, USA 3. Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA 4. Agricultural Research Service, College Station, TX, 77845, USA 5. Institute of Ecosystem Studies, Millbrook, NY, 12545, USA 6. USDA Forest Service, Parsons, WV, 26287-0404, USA 7. University of Ghent, B-9000, Gent, Belgium 8. USDA Forest Service, Raleigh, NC, 27606, USA 9. USDA Forest Service, Durham, NH, 03824-0640, USA 10. University of California, Santa Barbara, CA, 93106-9610, USA 11. US Environmental Protection Agency, Corvallis, OR, 97333-4902, USA 12. Centre for Ecology and Hydrology, Bangor, LL57 2UP, UK 13. Danish Centre for Forest, Landscape and Planning, H?rsholm, KVL, DK-2970, DK 14. Norwegian Forest Research Institute, N-1432, Aas, Norway 15. University of Florida, Gainesville, FL, 32611, USA 16. University of New Hampshire, Durham, NH, 03824, USA 17. Alabama A&M University, Normal, AL, 35762, USA 18. SUNY School of Environmental Science and Forestry, Syracuse, NY, 13210, USA 19. The University of Michigan, Ann Arbor, MI, 48109-1048, USA 20. University of Vermont, Burlington, VT, 05405, USA 21. Grand Valley State University, Allendale, MI, 49401, USA 22. University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada 23. Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903, Birmensdorf, Switzerland 24. University of Amsterdam, 1018 WV, Amsterdam, NL |
| Abstract: | N saturation induced by atmospheric N deposition can have serious consequences for forest health in many regions. In order to evaluate whether foliar  may be a robust, regional-scale measure of the onset of N saturation in forest ecosystems, we assembled a large dataset on atmospheric N deposition, foliar and root  and N concentration, soil C:N, mineralization and nitrification. The dataset included sites in northeastern North America, Colorado, Alaska, southern Chile and Europe. Local drivers of N cycling (net nitrification and mineralization, and forest floor and soil C:N) were more closely coupled with foliar  than the regional driver of N deposition. Foliar  increased non-linearly with nitrification:mineralization ratio and decreased with forest floor C:N. Foliar  was more strongly related to nitrification rates than was foliar N concentration, but concentration was more strongly correlated with N deposition. Root  was more tightly coupled to forest floor properties than was foliar  . We observed a pattern of decreasing foliar  values across the following species: American beech>yellow birch>sugar maple. Other factors that affected foliar  included species composition and climate. Relationships between foliar  and soil variables were stronger when analyzed on a species by species basis than when many species were lumped. European sites showed distinct patterns of lower foliar  , due to the importance of ammonium deposition in this region. Our results suggest that examining  values of foliage may improve understanding of how forests respond to the cascading effects of N deposition. |
| Keywords: | 15N Fine roots Forests N deposition Natural abundance |
| 本文献已被 SpringerLink 等数据库收录！ | |