Effects of typhoon disturbances on seasonal and interannual patterns of litterfall on coniferous and broadleaf plantations in Xitou, central Taiwan

摘要

Many environmental and climatic disturbances can significantly change the magnitude and pattern of litterfall. This study investigated the effects of typhoon disturbances on the seasonal and interannual patterns of litterfall on coniferous and broadleaf plantation stands in Xitou, central Taiwan. Throughout the study period from 2012 to 2018, typhoon disturbances were recorded in 4 of these 7 years, whereas only minor or even no typhoon disturbances occurred in the other 3 years. Our results demonstrated that the pattern of monthly litterfall varied substantially between the coniferous and broadleaf stands. The coniferous stands exhibited a substantial litterfall pulse due to typhoon disturbances. By contrast, typhoon disturbances exerted a minor impact on the broadleaf stands. The litterfall seasonality of the coniferous stands was higher than that of the broadleaf stands, especially in the years with typhoon disturbances. Furthermore, the yearly variation caused by typhoon disturbances was distinct at the coniferous stands; the annual litterfall mass at the coniferous stands in the years with typhoon disturbances was more than twice as high as that in the years without typhoon disturbances, namely 6,000 kg ha(-1) yr(-1) versus 2,500 kg ha(-1) yr(-1). By contrast, the annual litterfall mass at the broadleaf stands did not differ significantly among the study years. Because of high interannual variation, long-term sampling is essential for accurate estimation of annual litterfall at coniferous stands. For broadleaf plantations, interannual litterfall variation seems less critical, and spatial variability should be considered because of higher variability in terms of site conditions.