Diversity-stability relationships in multitrophic systems: an empirical exploration
Diversity-stability relationships in multitrophic systems: an empirical exploration
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DOI：
10.1046/j.1365-2656.2003.00744.x
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发表时间：
2003-09-01
影响因子：
4.8
通讯作者：
Amarasekare, P
中科院分区：
文献类型：
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作者：
Amarasekare, P
1.多样性与稳定性之间的关系是理解多营养相互作用动态的关键。关于多样性和稳定性之间的因果联系，有两个基本假设。第一，资源丰度的波动允许消费者共存，从而增加消费者营养水平的多样性(资源可变性假说)。第二，共存的消费物种之间的相互作用降低了消费者效率，抑制了人口波动，从而提高了消费者-资源稳定性(消费者效率假说)。这两个假设导致了三个比较预测：(1)与仅由资源开发优势的消费物种入侵的资源种群相比，共存消费物种的资源种群的波动应更大(资源可变性)或更小(消费效率)；(2)在波动较大的资源种群中，平均资源丰度应更大(资源可变性)或更小(消费者效率)；(3)移除在资源开发方面较差的消费物种应增加或不影响资源种群波动(资源可变性)，或总是增加资源种群的波动(消费者效率)。我用来自寄主-多寄生蜂群落的数据验证了这些预测：小丑害虫(Murgantia Histrionica)和两种专门攻击虫卵的专业寄生蜂(Trissolcus Murgantiae和Ooencyrtus johnsonii)。与只有三翅目寄生蜂的寄主种群相比，有共生寄生蜂的当地寄主种群的波动较小，平均丰度较大，三星天牛是最擅长利用寄主的物种。失去Ooencyrtus的当地种群与那些没有失去寄主种群的种群相比，表现出更多的寄主种群波动。这一结果与资源可变性假说的预期相矛盾，表明寄主种群的波动不太可能推动寄生蜂共存。它们符合消费者效率假说，即共存的寄生蜂物种之间的相互作用会抑制寄主种群的波动。我讨论了这些结果的含义以及可能的警告。
1. The relationship between diversity and stability is crucial in understanding the dynamics of multitrophic interactions. There are two basic hypotheses about the causal link between diversity and stability. The first is that fluctuations in resource abundance allow consumer coexistence, thus increasing diversity at the consumer trophic level (resource variability hypothesis). The second is that interactions between coexisting consumer species reduce consumer efficiency and dampen population fluctuations, thus increasing consumer-resource stability (consumer efficiency hypothesis).2. The two hypotheses lead to three comparative predictions: (i) fluctuations should be greater (resource variability) or smaller (consumer efficiency) in resource populations with coexisting consumer species, compared to those invaded only by the consumer species superior at resource exploitation; (ii) average resource abundance should be greater (resource variability) or smaller (consumer efficiency) in resource populations with greater fluctuations; and (iii) removal of the consumer species inferior at resource exploitation should increase or not affect resource population fluctuations (resource variability), or always increase them (consumer efficiency).3. I tested these predictions with data from a host-multiparasitoid community: the harlequin bug (Murgantia histrionica) and two specialist parasitoids (Trissolcus murgantiae and Ooencyrtus johnsonii) that attack the bug's eggs.4. Local host populations with coexisting parasitoids exhibited smaller fluctuations and greater average abundance compared to those with just Trissolcus, the species superior at host exploitation. Local populations that lost Ooencyrtus, the species inferior at host exploitation, exhibited an increase in host population fluctuations compared to those that did not.5. The results contradict the expectations of the resource variability hypothesis, suggesting that host population fluctuations are unlikely to be driving parasitoid coexistence. They are consistent with the consumer efficiency hypothesis, that interactions between coexisting parasitoid species dampens host population fluctuations. I discuss the implications of these results as well as possible caveats.