Because the banks have been eroded and are poor in nutriments, NTNU biology professor Wang Ying says, the variety and quantity of life in the ravines are limited and the food chain is simple.
師大生物系副教授王穎的解釋是，溪澗空間狹窄，加上兩岸受水流侵蝕，土質貧瘠，可提供的養分少，生物的種類、數量自然也不多，形成的食物鍊很簡單。