不同空間尺度的棲息地河段地文因子與魚類豐度之關係探討

Abstract

本研究探討不同空間尺度的棲息地地文因子與魚類豐度之關係，嘗試應用地理 資訊系統分析地文因子與魚類分佈的關聯性。研究區域為台灣南部楠梓仙溪流域， 蒐集相關地文圖層資料及魚類資料，再以環域分析取得不同空間尺度下的四個地文 因子與魚類豐度作回歸分析。環域半徑分別為 100、300、500、1000 和 1500 公尺； 地文因子為河段長、平均坡度、平均高程和蜿蜒度。複回歸分析結果顯示台灣石 (Acrossocheilus paradoxus)的平均密度和環域半徑 300 公尺內的地文因子有高度關 連，台灣馬口魚(Candidia barbata)、高身鯝魚(Onychostoma alticorpus)以及鯝魚 (Onychostoma barbatula)與地文因子沒有統計上的關連。在乾溼季分析結果發現台灣 石 的平均密度在溼季和 91 年 300 以及 92 年 1000 公尺內的地文因子有顯著性；另 外，鯝魚在溼季 91 與 92 年的環域半徑 1000 和 1500 公尺、乾季 91 和 93 年的環域 半徑 1000 以及 1500 公尺平均密度與地文因子也有高度關連。This study attempted to examine the relationships between landscape features and fish abundance in a mountain stream of Taiwan with GIS analysis and multiple regressions. The study tried to prove availability to make prediction of fish distribution with GIS analysis on landscape features. The study area is along the middle part of Cishan Stream catchment, Kaoshiung City, Taiwan. Documented data of fish abundance and landscape features were used for the analysis. Five buffer radii, 100, 300, 500, 1000, and 1500 meters, were applied for buffer analysis to get landscape features of different spatial scales, including stream length, stream sinuosity, average altitude, and average slope. The regression results showed that density of Acrossocheilus paradoxus was highly related to 300 meters landscape features, but densities of Candidia barbata and Onychostoma alticorpus were not significant related to landscape feathers of any scale. The dry-wet seasonal results revealed that wet season density of Acrossocheilus paradoxus was related to landscape features within 300 meters in 2002 and within 1000 meters in 2003. In the other hand, density of Onychostoma barbatula also was related with landscape features within 1000 and 1500 meters in wet season of 2002 and 2003, and in dry season of 2002 and 2004.