Tropical amphibian populations experience higher disease risk in natural habitats
Tropical amphibian populations experience higher disease risk in natural habitats
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DOI：
10.1073/pnas.1014497108
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发表时间：
2011-06-14
影响因子：
11.1
通讯作者：
Zamudio, Kelly R.
中科院分区：
文献类型：
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作者：
Becker, C. Guilherme;Zamudio, Kelly R.
栖息地丧失和疾病是全球两栖动物减少的主要驱动因素，但它们之间的相互作用在很大程度上仍未被探索。在这里，我们表明，自相矛盾的是，栖息地的丧失是负相关的发生，患病率和感染强度的壶菌菌Batrachochytrium dendrobavirus（Bd）在热带地区的两栖动物种群。在一个大的空间尺度上，增加栖息地的丧失预测在整个哥斯达黎加和澳大利亚东部的两栖动物种群的疾病风险较低，即使在共同考虑潜在的生物和非生物相关的影响。较低的主机物种丰富度和次优的小气候为Bd在干扰的栖息地是潜在的机制，这种模式。此外，我们发现，人为砍伐森林的做法偏向低地和自然植被留在人迹罕至的高地解释增加Bd发生在高海拔地区。在一个较小的空间尺度上，保持恒定的海拔，纬度和大气候，我们还发现了栖息地的丧失，并在巴西大西洋森林的两个景观中的青蛙种群的Bd患病率和感染强度之间的负相关关系。我们的研究结果表明，在原始环境中，两栖动物将不成比例地受到新出现的疾病的影响，而且，矛盾的是，受干扰的栖息地可能会成为疾病的避难所，但只有极少数物种能够容忍森林砍伐。因此，热带两栖动物区系受到自然生境的破坏以及原始森林疾病增加的威胁。为了遏制进一步的灭绝，并制定有效的缓解和恢复计划，我们必须关注栖息地丧失和疾病之间的相互作用，这是全球两栖动物减少的两个主要因素。
Habitat loss and disease are main drivers of global amphibian declines, yet the interaction between them remains largely unexplored. Here we show that paradoxically, habitat loss is negatively associated with occurrence, prevalence, and infection intensity of the chytrid fungus Batrachochytrium dendrobatidis (Bd) in amphibian populations in the tropics. At a large spatial scale, increased habitat loss predicted lower disease risk in amphibian populations across Costa Rica and eastern Australia, even after jointly considering the effect of potential biotic and abiotic correlates. Lower host-species richness and suboptimal microclimates for Bd in disturbed habitats are potential mechanisms underlying this pattern. Furthermore, we found that anthropogenic deforestation practices biased to lowlands and natural vegetation remaining in inaccessible highlands explain increased Bd occurrence at higher elevations. At a smaller spatial scale, holding constant elevation, latitude, and macroclimate, we also found a negative relationship between habitat loss, and both Bd prevalence and infection intensity in frog populations in two landscapes of the Brazilian Atlantic Forest. Our results indicate that amphibians will be disproportionately affected by emerging diseases in pristine environments, and that, paradoxically, disturbed habitats may act as shelters from disease, but only for the very few species that can tolerate deforestation. Thus, tropical amphibian faunas are threatened both by destruction of natural habitats as well as increased disease in pristine forests. To curb further extinctions and develop effective mitigation and restoration programs we must look to interactions between habitat loss and disease, the two main factors at the root of global amphibian declines.