Effects of Typhoon Disturbances on Soil Microbial Activities in an Uplifted Coral Reef Tropical Forest, Southern Taiwan

颱風擾動對於臺灣南部高位珊瑚礁熱帶森林土壤微生物活性的影響

蔡呈奇(Chen-Chi Tsai) ； 廖俊豪(Jiung-Hao Liao) ； 王相華(Hsiang-Hua Wang) ； 許正一(Zeng-Yei Hseu)

《台灣林業科學》 22卷3期 (2007/09) Pp. 265-279

https://doi.org/10.7075/TJFS.200709.0265

摘要

Two sites of an uplifted coral reef forest in southern Taiwan were chosen, and soil microbial activities were analyzed by considering typhoon disturbances during 2004 and 2005. The aims of this study in the Kengting Uplifted Coral Reef Nature Reserve (KUCRNR) were to illustrate the effects of typhoon disturbances upon the spatial and temporal variations in soil microbial biomass and respiration. The vegetation of the ridge site on the exposed coral reef was dominated by Aglaia formosana and Pouteria obovata, and that of the valley site at the bottom between reefs was dominated by Pisonia umbellifera. Regarding microbial activities, the seasonal monitoring of soil microbial biomass carbon (MBC) and nitrogen (MBN) and basal respiration (CO2-C evolution) was conducted for surface soils at the 2 sites including the onsets of typhoon events. Six typhoons occurred in the study area in the 2 yr. The soil microbial activities significantly varied at the 2 sites. The effects of the disturbance events upon the soil system by the typhoons were highly variable in terms of temporal changes in MBC, MBN, and basal respiration for both sites. The MBC values in summer, autumn, and winter with typhoons were significantly (p ＜ 0.05) lower than those in spring without typhoons in both two sites during 2004, but these differences caused by typhoons were not found in 2005. These contradictory results in seasonal differences of MBC by typhoon disturbances were also found in MBN and basal respiration. Furthermore, the values of the above soil microbial activities at the ridge site are generally lower than those at the valley site, because of larger nutrient losses through runoff at the ridge site than at the valley site. The major driving force of runoff is the heavy rainfall during typhoon events associated with steep slopes of the ground surface. Nevertheless, the typhoon events disturbed these soil microbial activities which did not show discernible seasonal trends.

關鍵字

碳 ； 枯落物 ； 氮 ； 颱風擾動 ； 高位珊瑚礁森林

並列摘要

Two sites of an uplifted coral reef forest in southern Taiwan were chosen, and soil microbial activities were analyzed by considering typhoon disturbances during 2004 and 2005. The aims of this study in the Kengting Uplifted Coral Reef Nature Reserve (KUCRNR) were to illustrate the effects of typhoon disturbances upon the spatial and temporal variations in soil microbial biomass and respiration. The vegetation of the ridge site on the exposed coral reef was dominated by Aglaia formosana and Pouteria obovata, and that of the valley site at the bottom between reefs was dominated by Pisonia umbellifera. Regarding microbial activities, the seasonal monitoring of soil microbial biomass carbon (MBC) and nitrogen (MBN) and basal respiration (CO2-C evolution) was conducted for surface soils at the 2 sites including the onsets of typhoon events. Six typhoons occurred in the study area in the 2 yr. The soil microbial activities significantly varied at the 2 sites. The effects of the disturbance events upon the soil system by the typhoons were highly variable in terms of temporal changes in MBC, MBN, and basal respiration for both sites. The MBC values in summer, autumn, and winter with typhoons were significantly (p ＜ 0.05) lower than those in spring without typhoons in both two sites during 2004, but these differences caused by typhoons were not found in 2005. These contradictory results in seasonal differences of MBC by typhoon disturbances were also found in MBN and basal respiration. Furthermore, the values of the above soil microbial activities at the ridge site are generally lower than those at the valley site, because of larger nutrient losses through runoff at the ridge site than at the valley site. The major driving force of runoff is the heavy rainfall during typhoon events associated with steep slopes of the ground surface. Nevertheless, the typhoon events disturbed these soil microbial activities which did not show discernible seasonal trends.

並列關鍵字

carbon ； litterfall ； nitrogen ； typhoon disturbance ； uplifted coral reef forest