水庫集水區棲地評估及復育策略之研究

Abstract

水庫集水區之攔砂壩的建置，嚴重破壞水域生態環境，阻隔河川的生態廊道，並將其區隔成數個獨立棲地空間。加上風災沖刷干擾，許多河段棲地變為無生物跡象之空棲地環境，故應對其棲地環境投入生態復育之工作，藉由移地復育手法營造河川生態資源。復育作業的施行，需對河段棲地好壞有所了解，因此棲地環境應先進行評估與分析，而評價較高之棲地較有生態復育的潛能，應優先列選為執行移地復育作業的地點。 本研究採用市民版定性棲地評估指標(CQHEI)，以石門水庫集水區為示範區域，對其範圍內之溪流進行棲地環境評估，並將成果分級標示，用以判定溪流棲地環境的優劣程度。其次將評估紀錄之數據作標準偏差之分析，以理解棲地環境的變動程度和評估指標的相關性。由分析結果顯示，石門水庫整體河川棲地多屬Medium與Excellent等級，其中又以分屬於Extra等級的高遶溪、匹亞溪以及下文光溪棲地條件最佳，最適合施作移地復育。而由變動性分析得知當棲地評估等級愈好，其環境的變動性就愈低，結果顯示奎輝ST1至ST3、宇內ST2、卡拉ST3以及泰崗六個河段測點棲地較穩定，可選做為生態復育的候選地點。 經研究得知適用於移地復育之潛勢棲地應包含棲地評價等級優良、生物豐度低以及棲地環境變動性低三項因素。滿足此三要素的棲地空間才有執行生態復育的意義與價值。

The construction of the Sabo-Dams on the Catchment Area Reservoir cause the serious damage to the ecological environment of waters, ecological corridor is blocked, and resulting many independent habitat space. Coupled with many river habitats’ are no biological survival signs from erosion of typhoon, so the habitats’ of ecological restoration work needs to be the way of Ex situ Conservation. Quality of river habitat must to be comprehended before the implementation of the restoration operations starts. Therefore, the habitats’ assessment and analysis than the restoration work first be carried out, and habitats’ evaluation of higher priority should be given to the column selected as the location of the implementation of Ex Situ Conservation. This study used Citizens Qualitative Habitat Evaluation Index to assessment the river habitats’ in Shihmen Reservoir, and classification labeling the results of the assessment to determine the level of the pros and cons of the stream habitats’, and then assessment record data for the standard deviation of the analysis will be used to understand the changes in habitats’ extent and evaluation indicators. The analysis showed that the overall Shimen Reservoir river habitats’ are mostly Medium and Excellent Level, among them, Gaorao river, Piya river and Xiawenguang river habitats’ conditions are Extra Level, which are the most suitable applied Ex Situ Conservation. By the analysis of variability that the better when the habitats’ assessment level, the lower volatility of its environment, and the results shows there are six river points habitats’ are relatively stable：Kuihui ST1 to ST3, Yunei the ST2, Carla ST3 and Taigang, which are selectable as the candidate locations for ecological restoration. The research that applies to Ex Situ Conservation potential habitats’ should contain a good level the habitats’ evaluation, low biological abundance and habitat variability in low. The habitats’ space of ecological restoration which includes more than these three points are meaningful and valuable.