Ecological specialization and susceptibility to disturbance: Conjectures and refutations
Ecological specialization and susceptibility to disturbance: Conjectures and refutations
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DOI：
10.1086/339991
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发表时间：
2002-06-01
影响因子：
2.9
通讯作者：
Simberloff, D
中科院分区：
文献类型：
--
作者：
Vazquez, DP;Simberloff, D
物种生态位宽度与物种对干扰的反应有关。干扰通常被认为会对专家产生负面影响，而通才被认为会从干扰中受益;我们称之为“专业化干扰”假说。我们还提出了一个相关的假说（“专业化-不对称-干扰”假说），在这个假说下，专业化和不对称的相互作用可以解释物种对干扰的反应。我们使用来自被牛吃草的植物传粉系统的数据来测试这些假设（即，阿根廷南部的一种生物干扰。我们量化了物种相互作用的专门化，相互作用伙伴的专门化，以及物种对干扰的反应。我们没有发现专业化程度和物种对干扰的反应之间的关系。我们还发现，植物传粉者的相互作用往往是不对称的，在这个系统中，有一个给定的物种的专业化程度和专业化程度的相互作用的合作伙伴之间没有关系。然而，相互作用的不对称性并不能解释物种对干扰反应的变异性。因此，这两种假设都被我们的数据所拒绝。可能的原因包括未能评估关键资源，干扰的实质性直接影响，专业化的不准确措施，难以检测高度非线性关系，以及非实验方法的局限性。或者，事实上，专业化和对干扰的反应之间可能没有关系。
Niche breadth of species has been hypothesized to be associated with species' responses to disturbance. Disturbance is usually believed to affect specialists negatively, while generalists are believed to benefit from disturbance; we call this the "specialization-disturbance" hypothesis. We also propose an associated hypothesis (the "specialization-asymmetry-disturbance" hypothesis) under which both specialization and asymmetry of interactions would explain species' responses to disturbance. We test these hypotheses using data from a plant-pollinator system that has been grazed by cattle (i.e., a biological disturbance) in southern Argentina. We quantified specialization in species interactions, specialization of interaction partners, and species' responses to disturbance. We found no relationship between degree of specialization and a species' response to disturbance. We also found that plant-pollinator interactions tend to be asymmetric in this system; there was no relationship between the degree of specialization of a given species and the degree of specialization of its interaction partners. However, asymmetry of interactions did not explain the variability in species' responses to disturbance. Thus, both hypotheses are rejected by our data. Possible reasons include failure to assess crucial resources, substantial direct effects of disturbance, inaccurate measures of specialization, difficulty detecting highly nonlinear relationships, and limitations of a nonexperimental approach. Or, in fact, there may be no relationship between specialization and response to disturbance.