Early onset of secondary extinctions in ecological communities following the loss of top predators
Early onset of secondary extinctions in ecological communities following the loss of top predators
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DOI：
10.1111/j.1461-0248.2006.00893.x
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发表时间：
2006-04-01
期刊：
影响因子：
8.8
通讯作者：
Ebenman, B
中科院分区：
文献类型：
--
作者：
Borrvall, C;Ebenman, B
顶级捕食者对人类对生态系统造成的干扰的巨大脆弱性日益引起人们的关注。由于顶级捕食者经常对其猎物种群产生强大影响，因此它们的灭绝可能会对生态系统的结构和功能产生深远的影响。例如，据观察，局部捕食者的消失会引发一系列的二次灭绝。然而，这种二次灭绝所涉及的时间滞后仍未被探索。在这里，我们表明，与其他营养级物种的丧失相比，顶级捕食者的丧失导致模型群落中二次灭绝的发生明显更早。此外，在大多数情况下，二次灭绝的时间随着物种丰富度的增加而增加。如果局部二次灭绝发生得较早，那么它们就不太可能通过来自附近当地社区的物种移民来平衡。讨论了这些结果对群落持久性和保护优先事项的影响。
The large vulnerability of top predators to human-induced disturbances on ecosystems is a matter of growing concern. Because top predators often exert strong influence on their prey populations their extinction can have far-reaching consequences for the structure and functioning of ecosystems. It has, for example, been observed that the local loss of a predator can trigger a cascade of secondary extinctions. However, the time lags involved in such secondary extinctions remain unexplored. Here we show that the loss of a top predator leads to a significantly earlier onset of secondary extinctions in model communities than does the loss of a species from other trophic levels. Moreover, in most cases time to secondary extinction increases with increasing species richness. If local secondary extinctions occur early they are less likely to be balanced by immigration of species from local communities nearby. The implications of these results for community persistence and conservation priorities are discussed.