Marneweck Courtney J, Katzner Todd E, Jachowski David S
Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC, USA.
U.S. Geological Survey, Forest & Rangeland Ecosystem Science Center, Boise, ID, USA.
Glob Chang Biol. 2021 Jul;27(14):3383-3394. doi: 10.1111/gcb.15653. Epub 2021 May 10.
Scavenging is an important function within ecosystems where scavengers remove organic matter, reduce disease, stabilize food webs, and generally make ecosystems more resilient to environmental changes. Global change (i.e., changing climate and increasing human impact) is currently influencing scavenger communities. Thus, understanding what promotes species richness in scavenger communities can help prioritize management actions. Using a long-term dataset from camera traps deployed with animal carcasses as bait along a 1881 km latitudinal gradient in the Appalachian Mountains of eastern USA, we investigated the relative impact of climate and humans on the species richness and diversity of vertebrate scavengers. Our most supported models for both mammalian and avian scavengers included climatic, but not human, variables. The richness of mammalian and avian scavengers detected was highest during relatively warm (5-10°C) and dry (100-150 mm precipitation) winters, when food was likely limited and both reliance on and detection of carrion was high. The diversity of mammalian and avian scavengers detected was highest under drier conditions. We then used these results to project the future species richness of scavengers that would be detected within our sampling area and under the climate scenario of 2070 (emissions level RCP8.5). Our predictions suggest up to 80% and 67% reductions, respectively, in the richness of avian and mammalian scavengers that would be detected at baited sites. Climate-induced shifts in behavior (i.e., reduction in scavenging, even if present) at this scale could have cascading implications for ecosystem function, resilience, and human health. Further, our study highlights the importance of conducting studies of scavenger community dynamics within ecosystems across wide spatial gradients within temperate environments. More broadly, these findings build upon our understanding of the impacts of climate-induced adjustments in behavior that can likely have negative impacts on systems at a large scale.
食腐作用是生态系统中的一项重要功能，食腐动物可清除有机物质、减少疾病、稳定食物网，并总体上使生态系统对环境变化更具恢复力。全球变化（即气候变化和人类影响加剧）目前正在影响食腐动物群落。因此，了解促进食腐动物群落物种丰富度的因素有助于确定管理行动的优先次序。利用在美国东部阿巴拉契亚山脉沿1881公里纬度梯度设置的以动物尸体为诱饵的相机陷阱的长期数据集，我们研究了气候和人类对脊椎动物食腐动物物种丰富度和多样性的相对影响。我们对哺乳动物和鸟类食腐动物最支持的模型都包括气候变量，但不包括人类变量。在相对温暖（5 - 10°C）和干燥（降水量100 - 150毫米）的冬季，当食物可能有限且对腐肉的依赖和发现率都很高时，检测到的哺乳动物和鸟类食腐动物的丰富度最高。在更干燥的条件下，检测到的哺乳动物和鸟类食腐动物的多样性最高。然后，我们利用这些结果预测了在我们的采样区域内以及2070年气候情景（排放水平RCP8.5）下将检测到的未来食腐动物物种丰富度。我们的预测表明，在诱饵地点检测到的鸟类和哺乳动物食腐动物的丰富度将分别减少高达80%和67%。在这个尺度上，气候引起的行为变化（即食腐行为减少，即使存在）可能对生态系统功能（恢复力）和人类健康产生连锁影响。此外，我们的研究强调了在温带环境中跨广泛空间梯度对生态系统内食腐动物群落动态进行研究的重要性。更广泛地说，这些发现基于我们对气候引起的行为调整影响的理解，这种调整可能在大规模上对系统产生负面影响。
