Atmospheric deposition and forest canopy processes in a subtropical rainforest in southeast Asia-Taiwan

Numerous studies over the last 20 years have illudicated the influences of atmospheric deposition on the health of temperate forest ecosystems. But, many tropical and subtropical forests also experience high levels of atmospheric deposition. Forests in (sub)tropical regions represent critical biomes in terms of biodiversity and watershed protection among others. Therefore, there is a need for studies of air pollution-forest interactions in the (sub)tropical region.This study provides evidence that (sub)tropical forests show high rates of acid deposition and canopy cation leaching, similar to what were observed in temperate forests. Hence, there is no reason to believe that (sub)tropical forests are free from the threat of air pollution. This study also shows different patterns than those seen in temperate forests, e.g. low contribution of dry deposition and the importance of typhoons. Strong indirect evidence is provided suggesting that acid deposition in northeastern Taiwan is not solely from local on island sources. A regional approach involving tracing pollutants emitted by China will be necessary to control pollution arriving in northeastern Taiwan.This study examined air pollution-forest canopy interactions in a subtropical rain forest in northeastern Taiwan. The results indicate that (1) although spatial variability of throughfall characteristics was high for individual storms, it was greatly reduced on a seasonal and annual basis (2) like many polluted temperate forests, the subtropical rain forest studied is experiencing high levels of acid deposition (168 and 121 meq/m...