Intraspecific trait variation increases species diversity in a trait-based grassland model
Intraspecific trait variation increases species diversity in a trait-based grassland model
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DOI：
10.1111/oik.05567
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发表时间：
2019-03-01
期刊：
影响因子：
3.4
通讯作者：
Schlaegel, Ulrike E.
中科院分区：
文献类型：
--
作者：
Crawford, Michael;Jeltsch, Florian;Schlaegel, Ulrike E.
种内性状变异（ITV）被认为在群落组装中起着重要作用，但其影响的大小和方向还不清楚。虽然它可能是至关重要的，以更好地解释人口的持久性，物种的相互作用，因此生物多样性模式，操纵ITV在实验中是具有挑战性的。因此，我们将ITV纳入一个基于性状和个体的草地群落组装模型，通过增加植物功能性状的变异，从而推动生活史权衡。在模拟中改变ITV的量，我们研究其对成对共存的影响，然后在不同初始大小的社区的物种多样性。我们发现，ITV增加了最弱的物种入侵的能力，但这种影响并不扩展到社区水平，ITV的主要影响是增加竞争力平均物种的持久性和丰富性。初始社区的多样性也是至关重要的，在确定ITV的功效;以上的种间多样性的阈值，ITV不会进一步增加多样性。对于低于这一门槛的社区，ITV主要帮助增加那些原本多样性低的社区的多样性。这些研究结果表明，ITV积极保持多样性，帮助物种的边缘持久性，但主要是在栖息地相对较低的α和β多样性。
Intraspecific trait variation (ITV) is thought to play a significant role in community assembly, but the magnitude and direction of its influence are not well understood. Although it may be critical to better explain population persistence, species interactions, and therefore biodiversity patterns, manipulating ITV in experiments is challenging. We therefore incorporated ITV into a trait- and individual-based model of grassland community assembly by adding variation to the plants' functional traits, which then drive life-history tradeoffs. Varying the amount of ITV in the simulation, we examine its influence on pairwise-coexistence and then on the species diversity in communities of different initial sizes. We find that ITV increases the ability of the weakest species to invade most, but that this effect does not scale to the community level, where the primary effect of ITV is to increase the persistence and abundance of the competitively-average species. Diversity of the initial community is also of critical importance in determining ITV's efficacy; above a threshold of interspecific diversity, ITV does not increase diversity further. For communities below this threshold, ITV mainly helps to increase diversity in those communities that would otherwise be low-diversity. These findings suggest that ITV actively maintains diversity by helping the species on the margins of persistence, but mostly in habitats of relatively low alpha and beta diversity.