Controls on nitrogen flux in alpine/subalpine watersheds
Abstract. High-altitude watersheds in the Front Range of Colorado show symptoms of advanced stages of nitrogen excess, despite having less nitrogen in atmospheric deposition than other regions where watersheds retain nitrogen. In two alpine/subalpine subbasins of the Loch Vale watershed, atmospheric...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.531.9243 2023-05-15T18:40:37+02:00 Controls on nitrogen flux in alpine/subalpine watersheds Donald H. Campbell Jill S. Baron Kathy A. Tonnessen Paul D. Brooks Paul F. Schuster S The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.531.9243 http://co.water.usgs.gov/lochvale/pdfs/Campbell_2000.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.531.9243 http://co.water.usgs.gov/lochvale/pdfs/Campbell_2000.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://co.water.usgs.gov/lochvale/pdfs/Campbell_2000.pdf text ftciteseerx 2016-01-08T10:39:04Z Abstract. High-altitude watersheds in the Front Range of Colorado show symptoms of advanced stages of nitrogen excess, despite having less nitrogen in atmospheric deposition than other regions where watersheds retain nitrogen. In two alpine/subalpine subbasins of the Loch Vale watershed, atmospheric deposition of NO•- plus NH•- was 1 1 3.2-5.5 kg N ha-, and watershed export was 1.8-3.9 kg N ha- for water years 1992-1997. Annual N export increased in years with greater input of N, but most of the additional N was retained in the watershed, indicating that parts of the ecosystem are nitrogen-limited. Dissolved inorganic nitrogen (DIN) concentrations were greatest in subsurface water of talus landscapes, where mineralization and nitrification augment high rates of atmospheric deposition of N. Tundra landscapes had moderately high DIN concentrations, whereas forest and wetland landscapes had low concentrations, indicating little export of nitrogen from these landscapes. Between the two subbasins the catchment of Icy Brook had greater retention of nitrogen than that of Andrews Creek because of landscape and hydrologic characteristics that favor greater N assimilation in both the terrestrial and aquatic ecosystems. These results suggest hat export of N from alpine/subalpine watersheds is caused by a combination of direct flushing of N from atmospheric deposition and release of N from ecosystem biogeochemical processes (N cycling). Sensitivity of alpine ecosystems in the western United States to atmospheric deposition of N is a function of landscape heterogeneity, hydrologic flow paths, and climatic extremes that limit primary productivity and microbial activity, which, in turn, control retention and release of nitrogen. Conceptual and mechanistic models of N excess that have been developed for forested ecosystems need to be modified in order to predict the response of alpine ecosystems to future changes in climate and atmospheric deposition of N. 1. Text Tundra Unknown Andrews Creek ENVELOPE(-126.653,-126.653,53.783,53.783) |
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English |
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Abstract. High-altitude watersheds in the Front Range of Colorado show symptoms of advanced stages of nitrogen excess, despite having less nitrogen in atmospheric deposition than other regions where watersheds retain nitrogen. In two alpine/subalpine subbasins of the Loch Vale watershed, atmospheric deposition of NO•- plus NH•- was 1 1 3.2-5.5 kg N ha-, and watershed export was 1.8-3.9 kg N ha- for water years 1992-1997. Annual N export increased in years with greater input of N, but most of the additional N was retained in the watershed, indicating that parts of the ecosystem are nitrogen-limited. Dissolved inorganic nitrogen (DIN) concentrations were greatest in subsurface water of talus landscapes, where mineralization and nitrification augment high rates of atmospheric deposition of N. Tundra landscapes had moderately high DIN concentrations, whereas forest and wetland landscapes had low concentrations, indicating little export of nitrogen from these landscapes. Between the two subbasins the catchment of Icy Brook had greater retention of nitrogen than that of Andrews Creek because of landscape and hydrologic characteristics that favor greater N assimilation in both the terrestrial and aquatic ecosystems. These results suggest hat export of N from alpine/subalpine watersheds is caused by a combination of direct flushing of N from atmospheric deposition and release of N from ecosystem biogeochemical processes (N cycling). Sensitivity of alpine ecosystems in the western United States to atmospheric deposition of N is a function of landscape heterogeneity, hydrologic flow paths, and climatic extremes that limit primary productivity and microbial activity, which, in turn, control retention and release of nitrogen. Conceptual and mechanistic models of N excess that have been developed for forested ecosystems need to be modified in order to predict the response of alpine ecosystems to future changes in climate and atmospheric deposition of N. 1. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Donald H. Campbell Jill S. Baron Kathy A. Tonnessen Paul D. Brooks Paul F. Schuster S |
spellingShingle |
Donald H. Campbell Jill S. Baron Kathy A. Tonnessen Paul D. Brooks Paul F. Schuster S Controls on nitrogen flux in alpine/subalpine watersheds |
author_facet |
Donald H. Campbell Jill S. Baron Kathy A. Tonnessen Paul D. Brooks Paul F. Schuster S |
author_sort |
Donald H. Campbell |
title |
Controls on nitrogen flux in alpine/subalpine watersheds |
title_short |
Controls on nitrogen flux in alpine/subalpine watersheds |
title_full |
Controls on nitrogen flux in alpine/subalpine watersheds |
title_fullStr |
Controls on nitrogen flux in alpine/subalpine watersheds |
title_full_unstemmed |
Controls on nitrogen flux in alpine/subalpine watersheds |
title_sort |
controls on nitrogen flux in alpine/subalpine watersheds |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.531.9243 http://co.water.usgs.gov/lochvale/pdfs/Campbell_2000.pdf |
long_lat |
ENVELOPE(-126.653,-126.653,53.783,53.783) |
geographic |
Andrews Creek |
geographic_facet |
Andrews Creek |
genre |
Tundra |
genre_facet |
Tundra |
op_source |
http://co.water.usgs.gov/lochvale/pdfs/Campbell_2000.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.531.9243 http://co.water.usgs.gov/lochvale/pdfs/Campbell_2000.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766230019905945600 |