Habitat destruction and degradation are the leading causes of species declines and extinctions in the world. Human altered landscapes often leave fragments of previously continuous habitat, which may be of significant conservation value. We assessed the effects of habitat fragmentation on the taxonomic diversity, community composition, and nestedness of avian communities before and after fragment isolation at the Biological Dynamics of Forest Fragments Project research site in the Amazon rainforest. Species loss in 10ha and 100ha fragments was significantly different from random taxonomic loss. In addition, after fragment isolation, but not prior to fragmentation, the species in the 10ha fragments were a nested subset of the species in the 100ha fragments. Finally, within the fragments two distinct communities formed, those on the edge of the fragments and those at the interior of the fragments, indicating that edge species did not penetrate the interior portion of the fragments. The controlled isolation of fragments from continuous forest resulted in rapid changes in the taxonomic diversity and species composition where fragment size served as a driver of species assemblages across the landscape. We suggest that future research continue to assess community level adjustments to habitat fragmentation and investigate the drivers behind the non-random loss of taxonomic groups and the nested structure of species composition of smaller fragments into larger ones after habitat fragmentation.

生境的破坏和退化是世界物种减少和灭绝的主要原因。人为改变的景观通常会留下以前连续的栖息地碎片，这可能具有重大的保护价值。我们在亚马逊雨林的“森林碎片的生物动力学”项目研究地点评估碎片分离前后，栖息地破碎对鸟类群落分类多样性，群落组成和巢度的影响。10ha和100ha片段中的物种损失与随机分类学损失显着不同。此外，在片段分离后但不在片段化之前，10ha片段中的物种是100ha片段中物种的嵌套子集。最后，在碎片中形成了两个不同的社区，碎片边缘的碎片和碎片内部的碎片，表明边缘物质没有穿透碎片的内部。碎片从连续森林中的受控隔离导致分类学多样性和物种组成的快速变化，其中碎片大小是整个景观中物种集合的驱动力。我们建议，未来的研究应继续评估社区水平对生境破碎化的调整，并调查生物分类群非随机丧失以及生境破碎化后较小碎片变成较大碎片的物种组成的嵌套结构背后的驱动因素。碎片从连续森林中的受控隔离导致分类学多样性和物种组成的快速变化，其中碎片大小是整个景观中物种集合的驱动力。我们建议，未来的研究应继续评估社区水平对生境破碎化的调整，并调查生物分类群非随机丧失以及生境破碎化后较小碎片变成较大碎片的物种组成的嵌套结构背后的驱动因素。碎片从连续森林中的受控隔离导致分类学多样性和物种组成的快速变化，其中碎片大小是整个景观中物种集合的驱动力。我们建议，未来的研究应继续评估社区水平对生境破碎化的调整，并调查生物分类群非随机丧失以及生境破碎化后较小碎片变成较大碎片的物种组成的嵌套结构背后的驱动因素。