An empirical test of stable species coexistence in an amphipod species complex
An empirical test of stable species coexistence in an amphipod species complex
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DOI：
10.1007/s00442-015-3262-1
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发表时间：
2015-07-01
期刊：
影响因子：
2.7
通讯作者：
Relyea, Rick A.
中科院分区：
文献类型：
--
作者：
Cothran, Rickey D.;Noyes, Patrick;Relyea, Rick A.
表型相似的物种在局部尺度上共存的能力是自相矛盾的，因为彼此非常相似的物种应该强烈竞争资源，从而受到竞争排斥。虽然理论已经确定了物种稳定共存的关键要求，但很少进行共存的经验测试。我们探索了物种稳定共存的一个关键要求：一个物种可以在一个群落最初稀有的时候入侵。我们还评估了初级生产力(通过磷的可用性操纵)是否通过增加可用资源量来影响入侵成功。通过两次中游实验和一组表型相似的角足类动物的组合，我们没有发现这三个种之间入侵成功的证据。此外，物种排除的模式在物种之间是不同的，这表明一个物种是一个特别差的竞争者。最后，这些模式是一致的，无论是用低水平的磷或高水平的磷来施肥。我们的结果表明，以前使用这些Hyalella物种的研究中发现的资源竞争和捕食者避免能力的物种差异可能不足以允许共存。此外，我们的研究证明了使用各种经验方法来检验物种共存理论的重要性。
The ability of phenotypically similar species to coexist at local scales is paradoxical given that species that closely resemble each other should compete strongly for resources and thus be subject to competitive exclusion. Although theory has identified the key requirements for species to stably coexist, empirical tests of coexistence have rarely been conducted. We explored a key requirement for species to stably coexist: a species can invade a community when it is initially rare. We also assessed whether primary productivity (manipulated using phosphorus availability) affected invasion success by increasing the amount of resources available. Using two mesocosm experiments and an assemblage of phenotypically similar amphipod species in the genus Hyalella, we found no evidence for invasion success among the three Hyalella species. Further, patterns of species exclusions differed among the species, which suggests that one species is an especially poor competitor. Finally, these patterns were consistent regardless of whether mesocosms were fertilized with low or high levels of phosphorus. Our results, suggest that species differences in resource competition and predator avoidance ability found in previous studies using these Hyalella species may not be sufficient to allow for coexistence. Moreover, our study demonstrates the importance of using a variety of empirical approaches to test species coexistence theory.