鰲鼓海岸濕地浮游生物群聚之季節變化

Seasonal Variation in the Planktonic Community of Aoku Coastal Wetland

本研究是探討嘉義縣鰲鼓海岸濕地浮游生物群聚在不同環境及季節的分布特徵，於1995-1996年期間，在研究區設置14個固定測站，進行四季的浮游生物樣本採集及環境因子之測量。結果顯示，植物性浮游生物的組成於不同季節有明顯的變化，冬春兩季是其繁生的季節，在防風林內潮溝春季有大量的微藻；海岸潮間帶夏季有大量的洛氏角刺藻（Chaetoceros lorenzianum）；極大量的梭形菱形藻（Nitzschia closterium）出現在草澤之冬季。植物性浮游生物以矽藻類的梭形菱形藻、洛氏角刺藻及中型曲舟藻（Pleurosigma intermedium）出現樣點之頻度及數量較其他浮游生物高。動物性浮游生物的數量在季節間也有明顯的差異，春季是其繁生的季節，纖毛蟲類鐘形蟲（Epistylis coronata）之族群密度在春季的水塘及排水溝明顯高於其他測站。 This study was conducted at the Aoku coastal wetland, Chia-yi County, Taiwan to determine the seasonal and environmental effects on the planktonic communities. Plankton samples were collectedseasonally at 14 sampling stations, 1995-1996. Phytoplankton were primarily influenced by seasons;they were abundant in spring and winter. The diatoms Nitzschia closterium, Chaetoceros lorenzianum,and Pleurosigma intermedium were the most dominant species at all sampling stations. Zooplanktonwere also primarily influenced by seasons; they were abundant in spring with particular abundance ofEpistylis coronata in ponds and ditches. Copepod larvae were common and their species compositionsvaried among sampling stations and more obviously among seasons. Seasonal variations in temperatureand precipitation, resulting in severe salinity fluctuation among sampling stations, were found to be themost important environmental factors affecting the planktonic communities. The dissolved oxygencontents and pH were influenced by the abundance and the species composition of plankton.