Ernest S K, Brown J H
Department of Biology, University of New Mexico, Albuquerque, NM 87131 USA.
Science. 2001 Apr 6;292(5514):101-4. doi: 10.1126/science.292.5514.101.
Because individual species can play key roles, the loss of species through extinction or their gain through colonization can cause major changes in ecosystems. For almost 20 years after kangaroo rats were experimentally removed from a Chihuahuan desert ecosystem in the United States, other rodent species were unable to compensate and use the available resources. This changed abruptly in 1995, when an alien species of pocket mouse colonized the ecosystem, used most of the available resources, and compensated almost completely for the missing kangaroo rats. These results demonstrate the importance of individual species and of colonization and extinction events in the structure and dynamics of ecosystems.
由于单个物种可能发挥关键作用，物种因灭绝而丧失或因定殖而增加，都可能导致生态系统发生重大变化。在美国奇瓦瓦沙漠生态系统中，实验性移除更格卢鼠近20年后，其他啮齿动物物种无法补偿并利用可用资源。1995年情况突然改变，当时一种外来囊鼠物种定殖到该生态系统，利用了大部分可用资源，几乎完全补偿了缺失的更格卢鼠。这些结果证明了单个物种以及定殖和灭绝事件在生态系统结构和动态中的重要性。
