Publication Date:
2011-12-17
Description:
Humans have more than doubled the amount of reactive nitrogen (Nr) added to the biosphere, yet most of what is known about its accumulation and ecological effects is derived from studies of heavily populated regions. Nitrogen (N) stable isotope ratios ((15)N:(14)N) in dated sediments from 25 remote Northern Hemisphere lakes show a coherent signal of an isotopically distinct source of N to ecosystems beginning in 1895 +/- 10 years (+/-1 standard deviation). Initial shifts in N isotope composition recorded in lake sediments coincide with anthropogenic CO(2) emissions but accelerate with widespread industrial Nr production during the past half century. Although current atmospheric Nr deposition rates in remote regions are relatively low, anthropogenic N has probably influenced watershed N budgets across the Northern Hemisphere for over a century.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Holtgrieve, Gordon W -- Schindler, Daniel E -- Hobbs, William O -- Leavitt, Peter R -- Ward, Eric J -- Bunting, Lynda -- Chen, Guangjie -- Finney, Bruce P -- Gregory-Eaves, Irene -- Holmgren, Sofia -- Lisac, Mark J -- Lisi, Peter J -- Nydick, Koren -- Rogers, Lauren A -- Saros, Jasmine E -- Selbie, Daniel T -- Shapley, Mark D -- Walsh, Patrick B -- Wolfe, Alexander P -- New York, N.Y. -- Science. 2011 Dec 16;334(6062):1545-8. doi: 10.1126/science.1212267.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA. gholt@uw.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22174250" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
,
Medicine
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Natural Sciences in General
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Physics
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