Co-evolution of seed size and seed predation
Co-evolution of seed size and seed predation
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DOI：
10.1023/a:1006551720526
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发表时间：
1998-11-01
影响因子：
1.9
通讯作者：
Geritz, SAH
中科院分区：
文献类型：
--
作者：
Geritz, SAH
在种子大小和种子捕食的共同进化模型中使用进化稳定策略（ESS）方法，我表明，如果捕食者对不同种子大小的攻击率存在权衡，那么个体植物内的种子大小变化是有利的。单一种子大小在进化上并不稳定，因为最适合一种特定种子大小的捕食者无法阻止具有不同种子大小的植物的入侵。该模型生成以下预测。 ESS 由一系列连续的种子大小组成。小种子比大种子更容易受到攻击。资源丰富的植物和幼体死亡率低（与频率无关）的植物比资源少且幼体死亡率高的植物具有更多的可变种子。在仅由种子捕食调节的波动群体中，种子大小的变化比在（部分）由幼苗竞争调节的稳定群体中的种子大小变化更大。捕食者搜索行为并不直接影响ESS种子大小范围，但可能通过影响种群稳定性或幼苗竞争作为种群调节机制的重要性而产生间接影响。此外，如果捕食在空间上不均匀，则与捕食更均匀的情况相比，种子大小的分布更倾向于小种子。讨论了该模型在几种协同进化植物和捕食者物种系统中的应用。
Using the evolutionarily stable strategy (ESS) approach in a model for the co-evolution of seed size and seed predation, I show that seed size variation within individual plants is favoured if there is a trade-off in the predator's attack rate for different seed sizes. A single seed size is not evolutionarily stable because a predator that is optimally adapted to one particular seed size cannot prevent invasion by plants with a different seed size. The model generates the following predictions. The ESS consists of a continuous range of seed sizes. Small seeds tend to be attacked more frequently than big seeds. Plants with many resources and plants with low (frequency-independent) juvenile mortality have more variable seeds than plants with few resources and a high juvenile mortality. Seed size variation is higher in fluctuating populations regulated by seed predation alone than in stable populations (partially) regulated by seedling competition. Predator searching behaviour does not directly affect the ESS seed size range, but may have an indirect effect by affecting population stability or the significance of seedling competition as a population regulating mechanism. Moreover, seed size distributions are found to be more skewed in favour of small seeds if predation is spatially non-uniform than if predation is more even. Application of the model to systems of several co-evolving plant and predator species is discussed.