Changes in trophic ecology of mobile predators in response to rainforest degradation
Changes in trophic ecology of mobile predators in response to rainforest degradation
复制标题
雨林退化导致移动捕食者营养生态的变化
DOI：
10.1111/1365-2664.14396
复制
发表时间：
2023
影响因子：
5.7
通讯作者：
Kemp V
中科院分区：
文献类型：
--
作者：
Kemp V
热带森林的加速损失和退化导致迫切需要了解剩余森林的保护价值。虽然大多数研究都集中在群落组成和分类丰富度的响应上，但更敏感的栖息地退化响应可能是通过多面手捕食者营养复杂性的变化来体现的。食物网理论预测，随着栖息地的退化，捕食者的营养地位和生态位宽度都会下降，从而影响生物相互作用和生态系统功能。利用稳定同位素方法，我们分析了婆罗洲沙巴热带森林中一种重要的顶级捕食者：食虫蝙蝠的营养位置和生态位呼吸。我们的目的是确定在不同空间尺度的森林退化实验梯度中它们的营养生态响应。在景观尺度上，营养生态位宽度大幅缩小（78%），森林覆盖减少（26%）。然而，在树冠较低的生态系统中，食物链更长，这代表了局部栖息地的简化。不同回声定位行会间营养生态位呼吸和营养位置的显著差异为蝙蝠群落内不同行会间生态位划分提供了进一步的证据。总体而言，与传统的群落描述符（如多样性指标）相比，营养途径在不同退化程度的栖息地之间的功能重要变化更可靠。合成与应用。这项研究表明，栖息地质量阈值——低于这个阈值，我们看到营养复杂性的实质性变化——比以前认为的要高。我们的分析表明，应优先保护覆盖率在90%以上的森林斑块，而不是更严重退化的生态系统。由于这些影响是在砍伐后大约30年才被检测到的，因此它们可能反映了对森林退化的相对长期的响应。
Accelerating loss and degradation of tropical forests has led to a pressing need to understand the conservation value of remaining forests. Whereas most studies focus on the responses in community composition and taxonomic richness, more sensitive responses to habitat degradation are likely to be apparent through changes in the trophic complexity of generalist predators. Food web theory predicts that both trophic position and niche breadth of predators decrease with habitat degradation, with consequences for biotic interactions and ecosystem functioning.Using a stable isotope approach, we analysed trophic positions and niche breaths of an important guild of top predators: insectivorous bats, in the tropical forests of Sabah, Borneo. We aimed to determine the responses in their trophic ecology across an experimental gradient of forest degradation at different spatial scales.At the landscape scale, trophic niche breadth contracted substantially (78%) in association with a narrow reduction (26%) in forest cover. However, food chains were longer in ecosystems with lower tree canopies, representative of localised habitat simplification. Marked differences in trophic niche breath of and trophic position between echolocation guilds provided further evidence for inter‐guild niche partitioning within bat assemblages. Overall, the functionally important shifts in trophic pathways discriminated among habitats of varying degrees of degradation more reliably than conventional community descriptors, such as diversity metrics.Synthesis and applications. This study reveals that habitat quality thresholds—below which we see substantial changes to trophic complexity—are higher than previously considered. Our analysis suggests that patches of forest with cover above 90% should be prioritised for conservation over more highly degraded ecosystems. As these effects were detected after approximately 30 years post‐logging, they likely reflect relatively long‐term responses to forest degradation.