Historical changes in atmospheric nitrogen deposition to Cape Cod, Massachusetts, USA

摘要: Abstract We reconstructed the historical trends in atmospheric deposition of nitrogen to Cape Cod, Massachusetts, from 1910 1995 by compiling data literature sources, and adjusting for geographical methodological differences. The suggest that NO 3 -N wet this region increased a low 0.9 kg N ha −1  yr 1925 high approximately 4 kg N ha around 1980. trend has remained since early 1980s at 3.6 kg N ha . In contrast, NH 4 decreased more than mid 1920s about 1.5 kg N ha late-1940s until today. Emissions x Cod airshed rate 2.1 kg N ha per decade 1910, is an order magnitude higher deposition. Estimates emissions northeast United States Canada have slightly throughout century, but decrease N-NH + rates does not parallel estimates. total suggests overall increase through century 0.26 kg N ha decade. This may expose coastal forests addition that, if exceeded, could induce saturation loads adjoining estuaries.