Task 4

　　题目文章中介绍的词是autogenic succession, 意思大概是通过群落对环境的反作用使环境条件发生变化，由于这些变化了的条件的作用形成了新的群落而引起演替。听力中用了松树(pine tree)作为例子，最开始森林里非常的dry，阳光又充足， 松树长得就特别好，这时候松针(needle)就开始掉了，然后积攒在地上，然后土就变得非湿了。而且当松树长得特别好的时候，松树的shade会挡住阳光，这时候就非常适合oak tree生长了

　　托福口语模板及托福口语真题参考答案范文:

　　托福口语范文:

　　The autogenic succession means where the plant community causes the environment to change and this modification drives the succession. The professor talked about the pine trees in the forest. At the beginning, the forest was full of the sunlight and the soil was dry, so the pine trees were especially good. Then the needles started to fall and build up on the ground so that the soil became moisture; also, the pine trees' shade started to block the sunlight, the whole ground became shady. Contrary to the beginning, the whole environment started to be more suitable for oak trees.