魚類棲地多樣性與空間層級系統之關係探討及其於溪流復育之應用

Relationship between Fish Habitat Diversity and Hierarchical Spatial Framework and Its Application in River Restoration

本研究於高屏溪流域藉由單位棲息地之電魚法進行魚類棲地喜好度之生態調查。結果顯示台灣間爬岩鰍、高身鯝魚等不同魚種偏好不同特性之棲地（湍瀨、深流與深潭），即使同一魚種於生命週期不同階段所需求之棲地亦不同，如高身鯝魚幼魚偏好之底質粒徑較成魚廣泛，成魚主要生活於大漂石與小漂石棲地，成、幼魚對水深及流速之偏好也有所不同。將採樣之微棲地尺度（單位棲息地）擴大爲區段尺度（segment scale）與溪流尺度（stream scale）時，亦可發現台灣間爬岩鰍與高身鯝魚的成魚與幼魚之棲地，分別位於兩種不同物理環境型態的區段溪流，如台灣間爬岩鰍成魚在底質粒徑較大的區段溪流中有較大的魚類密度，而幼魚卻是與成魚相反。故進行魚類棲地復育設計時，不僅需要考量區段尺度的溪流棲地多樣性，溪流尺度的河川縱向棲地多樣性與棲地連結亦是必須的。

We used electrofishing to investigate microhabitat preferences of fishes in the Kao-Ping River. The results showed that the preferences differed at the reach scale among fish species (e.g. Hemimyzon formosanum and Onychostoma alticorpus) as well as between the adult and juvenile fish. Juveniles of O. alticorpus had a wider range of substrate preferences, while the adults only preferred the substrates composed of small and big boulders. They also differed in water velocity and depth preferences. In the segment scale and stream scale, the adults and juveniles of H. formosanum and O. alticorpus occurred in different areas of the stream with different physical environments. The density of the adults of H. formosanum was higher in areas with large sediment sizes but the juveniles in areas of the small sizes. For stream habitat restoration, habitat diversity at the segment scale and different habitat preferences of adult and juvenile fish should be incorporated in the design.