1] Center for Conservation Biology, Stanford University, Stanford, California 94305, USA [2] Department of Biology, Stanford University, Stanford, California 94305, USA.
1] Center for Conservation Biology, Stanford University, Stanford, California 94305, USA [2] Department of Biology, Stanford University, Stanford, California 94305, USA [3] Department of Environmental Science, Policy & Management, University of California, Berkeley, California 94720, USA [4] The Nature Conservancy, Berkeley, California 94705, USA.
Nature. 2014 May 8;509(7499):213-7. doi: 10.1038/nature13139. Epub 2014 Apr 16.
The equilibrium theory of island biogeography is the basis for estimating extinction rates and a pillar of conservation science. The default strategy for conserving biodiversity is the designation of nature reserves, treated as islands in an inhospitable sea of human activity. Despite the profound influence of islands on conservation theory and practice, their mainland analogues, forest fragments in human-dominated landscapes, consistently defy expected biodiversity patterns based on island biogeography theory. Countryside biogeography is an alternative framework, which recognizes that the fate of the world's wildlife will be decided largely by the hospitality of agricultural or countryside ecosystems. Here we directly test these biogeographic theories by comparing a Neotropical countryside ecosystem with a nearby island ecosystem, and show that each supports similar bat biodiversity in fundamentally different ways. The island ecosystem conforms to island biogeographic predictions of bat species loss, in which the water matrix is not habitat. In contrast, the countryside ecosystem has high species richness and evenness across forest reserves and smaller forest fragments. Relative to forest reserves and fragments, deforested countryside habitat supports a less species-rich, yet equally even, bat assemblage. Moreover, the bat assemblage associated with deforested habitat is compositionally novel because of predictable changes in abundances by many species using human-made habitat. Finally, we perform a global meta-analysis of bat biogeographic studies, spanning more than 700 species. It generalizes our findings, showing that separate biogeographic theories for countryside and island ecosystems are necessary. A theory of countryside biogeography is essential to conservation strategy in the agricultural ecosystems that comprise roughly half of the global land surface and are likely to increase even further.
岛屿生物地理学平衡理论是估计灭绝率的基础，也是保护科学的支柱。保护生物多样性的默认策略是指定自然保护区，将其视为人类活动的不毛之海中的岛屿。尽管岛屿对保护理论和实践产生了深远的影响，但在以人类为主导的景观中，与岛屿对应的大陆类似物——森林片段，一直违背了基于岛屿生物地理学理论的预期生物多样性模式。乡村生物地理学是一种替代框架，它认识到世界野生动物的命运将在很大程度上取决于农业或乡村生态系统的好客程度。在这里，我们通过比较一个新热带乡村生态系统和附近的一个岛屿生态系统，直接检验了这些生物地理学理论，并表明每个系统都以截然不同的方式支持类似的蝙蝠生物多样性。岛屿生态系统符合岛屿生物地理学对蝙蝠物种丧失的预测，其中水基质不是栖息地。相比之下，乡村生态系统在森林保护区和较小的森林片段中具有较高的物种丰富度和均匀度。与森林保护区和片段相比，森林砍伐后的乡村栖息地支持的蝙蝠群落物种较少，但均匀度相同。此外，由于许多使用人造栖息地的物种的丰度发生了可预测的变化，与森林砍伐栖息地相关的蝙蝠群落在组成上是新颖的。最后，我们对跨越 700 多种物种的蝙蝠生物地理学研究进行了全球荟萃分析。它概括了我们的发现，表明需要为乡村和岛屿生态系统制定单独的生物地理学理论。乡村生物地理学理论对于构成全球陆地表面约一半、且可能进一步增加的农业生态系统的保护策略至关重要。
