کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4425027 | 1619206 | 2012 | 11 صفحه PDF | دانلود رایگان |
Spatially explicit estimates of critical loads of nitrogen (N) deposition (CLNdep) for nutrient enrichment in aquatic ecosystems were developed for the Rocky Mountains, USA, using a geostatistical approach. The lowest CLNdep estimates (<1.5 ± 1 kg N ha−1 yr−1) occurred in high-elevation basins with steep slopes, sparse vegetation, and abundance of exposed bedrock and talus. These areas often correspond with areas of high N deposition (>3 kg N ha−1 yr−1), resulting in CLNdep exceedances ≥1.5 ± 1 kg N ha−1 yr−1. CLNdep and CLNdep exceedances exhibit substantial spatial variability related to basin characteristics and are highly sensitive to the NO3− threshold at which ecological effects are thought to occur. Based on an NO3− threshold of 0.5 μmol L−1, N deposition exceeds CLNdep in 21 ± 8% of the study area; thus, broad areas of the Rocky Mountains may be impacted by excess N deposition, with greatest impacts at high elevations.
► Critical loads maps for nutrient enrichment effects of nitrogen deposition.
► Critical load estimates show spatial variability related to basin characteristics.
► Critical loads are sensitive to the nitrate threshold value for ecological effects.
► Broad areas of the Rocky Mountains may be impacted by excess nitrogen deposition.
Journal: Environmental Pollution - Volume 166, July 2012, Pages 125–135