When does periodic variation in resource growth allow robust coexistence of competing consumer species?
When does periodic variation in resource growth allow robust coexistence of competing consumer species?
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DOI：
10.1890/02-0684
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发表时间：
2004-02-01
期刊：
影响因子：
4.8
通讯作者：
Abrams, PA
中科院分区：
文献类型：
--
作者：
Abrams, PA
这篇文章问在什么条件下，以及在何种程度上，在一个单一的共享有限资源的增长率的周期性变化，促进共存的两个竞争的消费者，不同的线性与非线性响应的资源。分析探讨了四个因素对允许共存的消费者特征范围的影响：（1）资源增长是生物还是非生物;（2）消费者减少资源数量的效率;（3）消费者对资源密度变化的人口反应的速度;（4）资源增长周期性的周期和幅度。当（1）资源增长是生物性的，（2）消费者效率相对较低时，两个反应线性差异很大的竞争者最有可能共存。对第三和第四种因素共存的影响可能更为复杂，特别是当资源是生物资源时。然而，在大多数情况下，共存发生在一个更广泛的条件下，线性消费者有一个更快的数值响应比非线性消费者，当环境波动的时间远远长于消费者群体的最小倍增时间。如果资源是生物的，消费者-资源循环可以由非线性消费者产生，环境循环可能会干扰或加强这些，收缩或扩大允许共存的条件。然而，内生周期和资源增长的周期性变化的相互作用一般具有高度的非加性共存的影响。这些发现有助于解释为什么以前很少有实验研究表明，由于消费者反应的相对非线性共存。
This article asks under what conditions and to what extent periodic variation in the growth rate of a single shared limiting resource facilitates the coexistence of two competing consumers that differ in having linear vs. nonlinear responses to that resource. The analysis explores the effects of four factors on the range of consumer characteristics that allow coexistence: (1) whether resource growth is biotic or abiotic; (2) the efficiency of the consumers in reducing the resource population; (3) the rapidity of the demographic response of the consumers to changes in resource density; and (4) the period and amplitude of the periodicity in resource growth. Coexistence of two competitors differing greatly in the linearity of their responses is most likely when (1) resource growth is biotic and (2) the consumers are relatively inefficient. The effects on coexistence of the third and fourth factors can be more complicated, particularly when the resource is biotic. However, in most cases coexistence occurs over a wider range of conditions when the linear consumer has a more rapid numerical response than the nonlinear consumer and when the period of environmental fluctuation is much longer than the minimum doubling time of the consumer populations. If the resource is biotic, consumer-resource cycles can be produced by the nonlinear consumer, and environmental cycles may either interfere with or reinforce these, contracting or expanding the conditions allowing coexistence. However, the interaction of endogenous cycles and periodic variation in resource growth generally has highly nonadditive effects on coexistence. These findings help explain why few previous experimental studies have demonstrated coexistence due to the relative nonlinearity of consumer responses.