“…Since the beginning of the 1990s, significant studies on acid deposition have been conducted from the macroscale perspective of pollution pattern, comprehensive monitoring, and control strategy of atmospheric S deposition in certain karst catchments in this region (e.g., Zhao et al, 1994;Seip et al, 1995). Other studies recently reported the effects of atmospheric S deposition on the chemical composition of soil and river water (focused mainly on soil acidification, aluminum remobilization, and increasing SO 4 2− concentration in river water) (e.g., Larssen et al, 1998;Zhao et al, 2001;Han and Liu, 2004;Li et al, 2008). However, to our knowledge, previous studies have focused mainly on the biogeochemical processes of S in soils; studies on their environmental implications in karst areas of southwestern China remain limited.…”