Human-modified landscapes alter mammal resource and habitat use and trophic structure
Human-modified landscapes alter mammal resource and habitat use and trophic structure
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人类改造的景观改变了哺乳动物资源和栖息地的利用以及营养结构
DOI：
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发表时间：
2019
影响因子：
11.1
通讯作者：
K. Ferraz
中科院分区：
文献类型：
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作者：
M. Magioli;M. Moreira;R. C. B. Fonseca;M. Ribeiro;M. G. Rodrigues;K. Ferraz
意义 了解野生动物资源和栖息地的利用对于支持保护行动至关重要。稳定同位素分析 (SIA) 是获取此类信息的有用方法。 SIA的样本可以通过间接、非侵入性的方法获得，有利于受威胁物种的研究。我们使用 SIA 比较了热带雨林保护区和人类改造景观之间的资源和栖息地利用以及哺乳动物的营养结构。我们的研究表明，人类改造景观中的哺乳动物呈现出改变的营养结构，并使用来自农业基质的食物，同时它们依赖于保护区的森林资源。我们的研究结果强调需要对农业基质进行有利的管理以支持野生动物的生存。人们已经研究了栖息地退化对生物多样性的广泛负面影响，但对自然农业景观矩阵的复杂影响仍然知之甚少。在这里，我们使用稳定的碳和氮同位素来检测南美洲生物多样性热点地区哺乳动物资源和栖息地利用以及保护区和人类改造景观（HML）之间营养结构的变化。我们将哺乳动物分为营养型行会，并比较了两个系统的资源利用（以 C3 和 C4 衍生的碳而言）、同位素生态位和营养结构。在 HML 中，大约三分之一的人仅以农业基质中的物品为食 (C4)，而在保护区，约 68% 的人依赖森林残余资源 (C3)。草食动物、杂食动物和肉食动物是在 HML 中加入 C4 碳最多的群体。食果动物在系统之间保持相同的资源使用（C3 资源），而食虫动物则没有表现出显着差异。除食虫动物外，HML 中的所有行会都呈现出比保护区更大的同位素生态位。我们在保护区观察到复杂的营养结构，从食草动物到食虫动物和肉食动物，δ15N 值不断增加，这与 HML 中的不同。这种差异的部分原因是物种的丧失和更替，主要是由于使用富氮食品的弹性物种的行为可塑性。我们的结论是，景观不能被视为栖息地/非栖息地二分法，因为 HML 中的农业景观矩阵为哺乳动物提供了栖息地和获取食物的机会。因此，有利的农业矩阵管理和减缓森林向农业的转变对于该地区的保护非常重要。
Significance Knowledge of resource and habitat use by wildlife is essential to support conservation actions. Stable isotope analysis (SIA) is a useful method for the acquisition of this type of information. Samples for SIA can be obtained through indirect and noninvasive methods, which is favorable for studies of threatened species. We used SIA to compare the resource and habitat use and trophic structure of mammals between preserved areas and human-modified landscapes in a tropical rainforest. Our study shows that mammals in human-modified landscapes present an altered trophic structure and use food items from the agricultural matrix, while they depend on forest resources in preserved areas. Our findings stress the need for favorable management of the agricultural matrix to support wildlife survival. The broad negative consequences of habitat degradation on biodiversity have been studied, but the complex effects of natural–agricultural landscape matrices remain poorly understood. Here we used stable carbon and nitrogen isotopes to detect changes in mammal resource and habitat use and trophic structure between preserved areas and human-modified landscapes (HMLs) in a biodiversity hot spot in South America. We classified mammals into trophic guilds and compared resource use (in terms of C3- and C4-derived carbon), isotopic niches, and trophic structure across the 2 systems. In HMLs, approximately one-third of individuals fed exclusively on items from the agricultural matrix (C4), while in preserved areas, ∼68% depended on forest remnant resources (C3). Herbivores, omnivores, and carnivores were the guilds that most incorporated C4 carbon in HMLs. Frugivores maintained the same resource use between systems (C3 resources), while insectivores showed no significant difference. All guilds in HMLs except insectivores presented larger isotopic niches than those in preserved areas. We observed a complex trophic structure in preserved areas, with increasing δ15N values from herbivores to insectivores and carnivores, differing from that in HMLs. This difference is partially explained by species loss and turnover and mainly by the behavioral plasticity of resilient species that use nitrogen-enriched food items. We concluded that the landscape cannot be seen as a habitat/nonhabitat dichotomy because the agricultural landscape matrix in HMLs provides mammal habitat and opportunities for food acquisition. Thus, favorable management of the agricultural matrix and slowing the conversion of forests to agriculture are important for conservation in this region.