Centre for Research on Ecological Impacts of Coastal Cities, Marine Ecology Laboratories A11, School of Biological Sciences, University of Sydney, NSW 2006, Australia.
Ecology. 2010 Jul;91(7):1908-15. doi: 10.1890/09-1083.1.
Despite a long history of work on relationships between area and number of species, the details of mechanisms causing patterns have eluded ecologists. The general principle that the number of species increases with the area sampled is often attributed to a sampling artifact due to larger areas containing greater numbers of individuals. We manipulated the patch size and surface area of experimental mimics of macro-algae to test several models that can explain the relationship between abundance and species richness of assemblages colonizing different habitats. Our results show that patch size and structural complexity have independent effects on assemblages of macroinvertebrates. Regardless of their structural complexity, larger habitats were colonized by more species. Patch size did not have a significant effect on numbers of individuals, so the increased number of species in larger habitats was not simply a result of random placement associated with sampling increased number of individuals. Similarly, random placement alone could not explain differences in numbers of species among habitats with different structural complexity, contrary to suggestions that the relationship between number of species and surface area might also be a sampling artifact due to more complex habitats having larger areas and therefore sampling more individuals. Future progress would benefit from manipulating properties of habitat in conjunction with experimental manipulations of area.
尽管人们长期以来一直在研究区域和物种数量之间的关系，但导致这些模式的机制细节仍让生态学家感到困惑。通常情况下，随着采样面积的增加，物种数量会增加，这一普遍规律归因于采样过程中的一个人为因素，因为较大的区域包含更多的个体。我们操纵了实验模拟大型藻类的斑块大小和表面积，以测试几种可以解释不同栖息地生物群集丰度和物种丰富度之间关系的模型。我们的研究结果表明，斑块大小和结构复杂性对大型无脊椎动物生物群集具有独立的影响。无论结构复杂性如何，较大的栖息地都有更多的物种栖息。斑块大小对个体数量没有显著影响，因此，较大栖息地中物种数量的增加并不是简单地由于与采样增加个体数量相关的随机放置所致。同样，与结构复杂性不同的栖息地之间物种数量的差异也不能仅用随机放置来解释，这与由于更复杂的栖息地面积更大，因此采样更多个体，因此物种数量与表面积之间的关系也可能是采样人为因素的观点相反。未来的研究进展将受益于对栖息地属性的操纵与对区域的实验操纵相结合。
