Buckley Lauren B, Jetz Walter
Santa Fe Institute, Santa Fe, NM 87501, USA.
Ecol Lett. 2007 Jun;10(6):481-9. doi: 10.1111/j.1461-0248.2007.01042.x.
The relative effects of resource availability and partitioning on animal population density are unresolved yet central to ecology and conservation. Species-depauperate islands offer an intriguing test case. Across 643 lizard populations from around the world, local abundances are one order of magnitude higher on islands than on mainlands, even when controlled for resource availability. On mainlands, predator and competitor richness only weakly correlate with lizard densities. On islands, sharp reductions in predator and competitor richness are the dominant drivers of lizard abundance. Our results demonstrate the dramatic effect insularity has on the interplay between biotic and abiotic control of animal abundances and the heightened sensitivity of island communities to species' losses and gains.
资源可用性和分配对动物种群密度的相对影响尚未得到解决，但却是生态学和保护学的核心问题。物种匮乏的岛屿提供了一个有趣的测试案例。在来自世界各地的643个蜥蜴种群中，即使在控制了资源可用性的情况下，岛屿上的局部丰度也比大陆上高一个数量级。在大陆上，捕食者和竞争者的丰富度与蜥蜴密度的相关性较弱。在岛屿上，捕食者和竞争者丰富度的急剧下降是蜥蜴丰度的主要驱动因素。我们的结果表明，岛屿性对动物丰度的生物和非生物控制之间的相互作用具有巨大影响，以及岛屿群落对物种增减的高度敏感性。
