Species diversity of grasses promotes genotypic diversity of clover populations in simulated communities
Species diversity of grasses promotes genotypic diversity of clover populations in simulated communities
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DOI：
10.1111/j.1600-0706.2011.19107.x
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发表时间：
2011-10-01
期刊：
影响因子：
3.4
通讯作者：
Vellend, Mark
中科院分区：
文献类型：
--
作者：
Adams, Rachel I.;Vellend, Mark
最近的群落遗传学研究表明，种内遗传变异对相互作用物种的多样性有很强的影响，但在很大程度上忽略了物种多样性对遗传多样性的影响，这也可能在这两个生物多样性水平之间产生正相关。在这里，我们调查的作用，竞争对手的物种多样性可以发挥在塑造一个焦点物种的基因型多样性，使用修改后的版本的草三叶草动态的现有模型。我们模拟社区中，三叶草基因型不同的相对竞争能力时，邻近不同的草种生长。在许多参数组合下，具有更大物种丰富度的草群落在三叶草种群中保留了更大的基因型丰富度。增加草物种丰富度有效地增加了生物环境异质性方面的三叶草生长，从而促进了基因型多样性的维护。这一结果取决于满足三个条件：（1）当与不同的草种生长时，基因型在其适合度方面的足够强的权衡，（2）竞争和促进的部分解耦，草和三叶草能够共享微位点而不是严格地彼此排斥，以及（3）三叶草生长和克隆扩散的足够高的速率，这使得三叶草基因型能够“跟踪”草种的变化镶嵌。我们的研究结果表明，物种多样性可以作为一个重要的基因型多样性的推动者，他们提供了可检验的预测有关的条件，促进这一结果的性质。
Recent studies in community genetics have demonstrated strong effects of intraspecific genetic variation on the diversity of interacting species but largely ignored the potential for effects of species diversity on genetic diversity, which could also create a positive correlation between these two levels of biodiversity. Here we investigated the role that species diversity of competitors could play in shaping the genotypic diversity of a focal species, using a modified version of an existing model of grass-clover dynamics. We simulated communities in which clover genotypes varied in their relative competitive ability when growing adjacent to different grass species. Under many parameter combinations, communities with greater species richness of grasses retained greater genotypic richness within the clover population. Increasing grass species richness effectively increased biotic environmental heterogeneity with respect to clover growth, thereby promoting the maintenance of genotypic diversity. This result depended on three conditions being met: (1) a sufficiently strong tradeoff among genotypes in their fitness when growing with different grass species, (2) partial de-coupling of competition and facilitation, with grass and clover capable of sharing microsites rather than strictly excluding one another, and (3) sufficiently high rates of clover growth and clonal spread, which allowed clover genotypes to 'track' the shifting mosaic of grass species. Our results demonstrate that species diversity can act as an important promoter of genotypic diversity, and they provide testable predictions concerning the conditions that promote this outcome in nature.