Van Allen Benjamin G, Rasmussen Nick L, Dibble Christopher J, Clay Patrick A, Rudolf Volker H W
BioSciences, Rice University, Houston, TX, USA.
Marine Biology Research Division, University of California San Diego, San Diego, CA, USA.
Ecol Lett. 2017 Aug;20(8):1004-1013. doi: 10.1111/ele.12798. Epub 2017 Jun 30.
Natural ecosystems are shaped along two fundamental axes, space and time, but how biodiversity is partitioned along both axes is not well understood. Here, we show that the relationship between temporal and spatial biodiversity patterns can vary predictably according to habitat characteristics. By quantifying seasonal and annual changes in larval dragonfly communities across a natural predation gradient we demonstrate that variation in the identity of top predator species is associated with systematic differences in spatio-temporal β-diversity patterns, leading to consistent differences in relative partitioning of biodiversity between time and space across habitats. As the size of top predators increased (from invertebrates to fish) habitats showed lower species turnover across sites and years, but relatively larger seasonal turnover within a site, which ultimately shifted the relative partitioning of biodiversity across time and space. These results extend community assembly theory by identifying common mechanisms that link spatial and temporal patterns of β-diversity.
自然生态系统是沿着空间和时间这两个基本轴形成的，但生物多样性如何在这两个轴上进行分配却尚未得到很好的理解。在这里，我们表明，根据栖息地特征，时间和空间生物多样性模式之间的关系可以有可预测的变化。通过量化自然捕食梯度上蜻蜓幼虫群落的季节性和年度变化，我们证明顶级捕食者物种身份的变化与时空β多样性模式的系统差异相关，导致不同栖息地在时间和空间上生物多样性相对分配的一致差异。随着顶级捕食者规模的增加（从无脊椎动物到鱼类），栖息地在不同地点和年份的物种更替率降低，但在一个地点内的季节性更替相对较大，这最终改变了生物多样性在时间和空间上的相对分配。这些结果通过识别连接β多样性的空间和时间模式的共同机制，扩展了群落组装理论。
