Saros,J.E., Clow,D.W., Blett,T. and Wolfe,A.P.(2011): Critical nitrogen deposition loads in high-elevation lakes of the western US inferred from paleolimnological records. Water Air Soil Pollut., 216, 193-202.

『古陸水学的記録から推定された米国西部の高地湖における臨界窒素沈着負荷量』


Abstract
 Critical loads of nitrogen (N) from atmospheric deposition were determined foe alpine lake ecosystems in the western US using fossil diatom assemblages in lake sediment cores. Changes in diatom species over the last century were indicative of N enrichment in two areas, the eastern Sierra Nevada, starting between 1960 and 1965, and the Greater Yellowstone Ecosystem, starting in 1980. In contrast, no changes in diatom community structure were apparent in lakes of Glacier National Park. To determine critical N loads that elicited these community changes, we modeled wet nitrogen deposition rates for the period in which diatom shifts first occurred in each area using deposition data spanning from 1980 to 2007. We determined a critical load of 1.4 kg N ha-1 year-1 wet N deposition to elicit key nutrient enrichment effects on diatom communities in both the eastern Sierra Nevada and the Greater Yellowstone Ecosystem.

Keywords: Critical load; Atmospheric nitrogen deposition; Alpine lake ecosystems; Diatoms』

1. Introduction
2. Methods
3. Results
4. Discussion
5. Conclusions
Acknowledgments
References


戻る