Analysis of nitrogen saturation potential in Rocky Mountain tundra and forest: implications for aquatic systems

Biogeochemistry
By: , and 

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Abstract

We employed grass and forest versions of the CENTURY model under a range of N deposition values (0.02–1.60 g N m−2 y−1) to explore the possibility that high observed lake and stream N was due to terrestrial N saturation of alpine tundra and subalpine forest in Loch Vale Watershed, Rocky Mountain National Park, Colorado. Model results suggest that N is limiting to subalpine forest productivity, but that excess leachate from alpine tundra is sufficient to account for the current observed stream N. Tundra leachate, combined with N leached from exposed rock surfaces, produce high N loads in aquatic ecosystems above treeline in the Colorado Front Range. A combination of terrestrial leaching, large N inputs from snowmelt, high watershed gradients, rapid hydrologic flushing and lake turnover times, and possibly other nutrient limitations of aquatic organisms constrain high elevation lakes and streams from assimilating even small increases in atmospheric N. CENTURY model simulations further suggest that, while increased N deposition will worsen the situation, nitrogen saturation is an ongoing phenomenon.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Analysis of nitrogen saturation potential in Rocky Mountain tundra and forest: implications for aquatic systems
Series title Biogeochemistry
DOI 10.1007/BF00002571
Volume 27
Issue 1
Year Published 1994
Language English
Publisher Dr W. Junk Publishers
Publisher location Boston, MA
Description 22 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Biogeochemistry
First page 61
Last page 82