摘要: Two research sites were established at 300- and 1800-m elevations in the southern Appalachian Mountains for the study of effects of atmospheric deposition on forest element cycles. Meteorological and chemical data are collected co... 展开 Two research sites were established at 300- and 1800-m elevations in the southern Appalachian Mountains for the study of effects of atmospheric deposition on forest element cycles. Meteorological and chemical data are collected continuously and on an event basis to compare the rate of wet and dry deposition to indigenous conifer forests. Climatic data confirm the expected differences in atmospheric exposure conditions between sites: precipitation, wind speed, and cloud or fog immersion time increase with elevation by factors of 2 to 50. Chemical data collected during the winter indicate comparable concentrations of most constituents in air and rain, while cloud water contains higher concentrations of acidity and acid anions than does fog water. All of these factors combine to create much higher deposition loading to the mountain site. Differences in dry deposition are reflected in significantly higher net throughfall fluxes in the high-elevation spruce stand. 收起