TPO extra 1 Passage 3.doc

地址: 北京市海淀区海淀北二街 8号中关村 SOHO A区2层电话: 400-890-6000 传真: 010-82607462 网址: 邮编:100080 TPO35 Passage 3 阅读文章和题目为了方便大家学习,这是小编为大家从模考软件里整理出来的 TPO35 Passage 3 的阅读文章和题目,这是最新的 TPO 了,大家还在等什么? W hat munity ? ? The Black Hills forest, the prairie riparian forest, and other forests of the western United States can be separated by the distinctly binations of species prise. It is easy to distinguish between prairie riparian forest and Black Hills forest — one isa broad-leaved forest of ash and cottonwood trees, the other isa coniferous forest of ponderosa pine and white spruce trees. One has kingbirds; the other juncos (birds with white outer tail feathers). The fact that munities are indeed, recognizable clusters of species led some early ecologists, particularly those living in the beginning of the twentieth century, to claim munities are highly integrated, precisely balanced assemblages. This claim harkens back to even earlier arguments about the existence ofa balance of nature, where every species is there for a specific purpose, like a vital part plex machine. Such a belief would suggest that to remove any species, whether it be plant, bird, or insect, would somehow disrupt the balance, and the habitat would begin to deteriorate. Likewise, to add a species may be equally disruptive. ? One of these pioneer ecologists was Frederick Clements, who studied ecology extensively throughout the Midwes