海狸被大量捕杀、过度捕杀,到19世纪它们几乎灭绝了,这意味着湿地和静水变得更少了。
Like birds and mammals that eat the fish and insects, and you get trees and plants that begin to grow near the standing water that can grow near the running water.就像鸟类和哺乳动物吃鱼和昆虫,你可以看到树木和植物开始在静水附近生长,而不能生长在流动的水附近。
Flowing waters like rivers and streams are called lotic ecosystems; standing water like lakes and ponds are lentic.像河流和小溪那样的流水称为激流生态系统;像湖泊和池塘的死水称为静水生态系统。