模擬氣候變遷對櫻花鉤吻鮭域外放流棲地水溫與潛在族群數之衝擊

外文標題: 
Modeling the Impacts of Climate Change on Water Temperature and Potential Population of Formosan Landlocked Salmon’s Reintroduction Habitat
校院系所: 
臺灣大學 生物環境系統工程學研究所
指導教授: 
童慶斌
出版年份: 
2004年
主題類別: 
摘要: 

本研究透過物理性的水溫模式及櫻花鈎吻鮭族群模式的建立來評估氣候變遷對櫻花鈎吻鮭域外放流棲地水溫與及潛在族群數之影響。將櫻花鉤吻鮭放流至目前沒有生存的溪流,將是未來幾年保育工作的重點之一。大甲溪上游的支流將是域外放流工作的首選地點,因為根據歷史紀錄,櫻花鉤吻鮭曾經在這些溪流生存過。因此本文的研究區即選定在大甲溪上游區域。水溫是一項重要的生態指標,尤其是用來評估冷水性鮭魚棲地環境的好壞;而魚群數量更是直接反應了魚群對於環境條件的適應程度。根據水溫模擬的結果,在氣候變遷之衝擊下,在此區域中水溫上升百分比最高的溪流為耳無溪的11.2%,水溫上升百分比最低溪流則為司界蘭溪的 7.8%。同時模擬結果亦顯示在冬季水溫上升的百分比約比夏季高出5%~10%,這個現象有可能會影響到櫻花鉤吻鮭11月的孵卵季節。另一方面,根據潛在族群數的模擬結果,在氣候變遷之衝擊下,耳無溪與畢祿溪潛在族群數量之下降百分比較高約15%,而司界蘭溪與有勝溪下降百分比較低約10%。因此根據模擬的結果,如果在評估域外放流適合度的時候,水溫以及潛在族群數的變化是唯二考量的因子,那麼司界蘭溪將是在此一區域中最適合進行域外放流的棲地。

外文摘要: 

A stream temperature model and a fish population model are built to assess the impacts of climate change on water temperature and potential population of Formosan Landlocked Salmon’s reintroduction habitat. Reintroducing Formosan Landlocked Salmon into the other creeks which they do not exist currently will be the main conservation strategy in the next few years. The upstream of the TaChia River is one of the suitable habitats because Formosan Landlocked Salmon once lived there, and thus is selected as the study area in this thesis. According to the simulation of water temperature, under different climate change scenarios, the highest and lowest increase percentage of water temperature in this area are 11.2% in the ErWu Creek, and 7.8% in the Sikairan Creek, respectively. Meanwhile, the percentage change in winter is about 5% to 10% higher than in summer. This result implies climate change may damage the incubation of Formosan Landlocked Salmon in November. On the other hand, under the impact of climate change, the higher decrease percentage of potential population may happen in the ErWu Creek and BiLu Creek (about 15%). The decrease in Sikairan Creek and YuShang Creek are lower (about 10%). The result shows that if water temperature and potential population change in the future are only two factors that have been considered when reintroducing Formosan Landlocked Salmon into the other creeks, the Sikairan Creek and is the most appropriate habitat in this area.