托福TPO作为托福的模考工具，它的题目对于我们备考托福很有参考价值，为了帮助大家备考，下面小编给大家整理了托福TPO3阅读真题原文Part3，望喜欢！
托福TPO3阅读真题原文Part3
The Long-Term Stability of Ecosystems
Plant communities assemble themselves flexibly, and their particular structure depends on the specific history of the area. Ecologists use the term "succession" to refer to the changes that happen in plant communities and ecosystems over time. The first community in a succession is called a pioneer community, while the long-lived community at the end of succession is called a climax community. Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes-in plant numbers and the mix of species-are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.
请关闭浏览器的畅读模式或者取消屏蔽JavaScript的正常运行，避免出现内容显示不全或者段落错乱。
原网页地址：https://www.potelypower.com/xuexi/456524.html