naa a22 4500 510752659 CHVBK 20180411083110.0 cr unu---uuuuu 180411e20130201xx s 000 0 eng 10.1007/s11270-012-1355-6 doi (NATIONALLICENCE)springer-10.1007/s11270-012-1355-6 Susceptibility of Forests in the Northeastern USA to Nitrogen and Sulfur Deposition: Critical Load Exceedance and Forest Health [Elektronische Daten] [N. Duarte, L. Pardo, M. Robin-Abbott] The objectives of this study were to assess susceptibility to acidification and nitrogen (N) saturation caused by atmospheric deposition to northeastern US forests, evaluate the benefits and shortcomings of making critical load assessments using regional data, and assess the relationship between expected risk (exceedance) and forest health. We calculated the critical loads of nutrient N and of sulfur (S) + N using the steady-state mass balance method at >4,000 regional and national vegetation and soil monitoring network plots in the northeastern USA. Regional calculations of critical loads necessitate use of soil maps which provide a range for each soil characteristic resulting in a broad range of critical load of S + N and exceedance values. For the scenario most representative of regional conditions, over 80% of the critical loads fell into the range of 850-2050eq ha−1 yr−1; at 45% of the plots, deposition exceeded the critical load. In contrast, the critical load for nutrient N, 200-300eq ha−1 yr−1, was lower. Site measurements, especially to estimate soil weathering, would increase the certainty of the critical load. We observed significant negative correlations between critical load exceedance and growth (17 species) and crown density (4 species); we observed significant positive correlations of exceedance with declining vigor (four species), with crown dieback (six species) and crown transparency (seven species). Among the species which demonstrate the most significant detrimental responses to atmospheric deposition are balsam fir, red spruce, quaking aspen, and paper birch. These results indicate that significant detrimental responses to atmospheric deposition are being observed across the northeastern USA. Springer Science+Business Media Dordrecht (outside the USA), 2013 Acidification nationallicence Base cation depletion nationallicence Forest health nationallicence N saturation nationallicence Simple mass balance model nationallicence Duarte N. University of Vermont Aiken Center, 81 Carrigan Drive, 05405, Burlington, VT, USA aut Pardo L. University of Vermont Aiken Center, 81 Carrigan Drive, 05405, Burlington, VT, USA aut Robin-Abbott M. University of Vermont Aiken Center, 81 Carrigan Drive, 05405, Burlington, VT, USA aut Water, Air, & Soil Pollution Springer Netherlands 224/2(2013-02-01), 1-21 0049-6979 224:2<1 2013 224 11270 https://doi.org/10.1007/s11270-012-1355-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11270-012-1355-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Duarte N. University of Vermont Aiken Center, 81 Carrigan Drive, 05405, Burlington, VT, USA aut NATIONALLICENCE 700 1- Pardo L. University of Vermont Aiken Center, 81 Carrigan Drive, 05405, Burlington, VT, USA aut NATIONALLICENCE 700 1- Robin-Abbott M. University of Vermont Aiken Center, 81 Carrigan Drive, 05405, Burlington, VT, USA aut NATIONALLICENCE 773 0- Water, Air, & Soil Pollution Springer Netherlands 224/2(2013-02-01), 1-21 0049-6979 224:2<1 2013 224 11270 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer