Nash Liam N, Recalde Fátima C, Chambers Timothy, Saito Victor S, Romero Gustavo Q, Kratina Pavel
Centre for Biodiversity and Sustainability, School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
Laboratory of Multitrophic Interactions and Biodiversity, Department of Animal Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo 13083-862, Brazil.
Proc Biol Sci. 2025 Jan;292(2038):20242423. doi: 10.1098/rspb.2024.2423. Epub 2025 Jan 8.
Riparian ecosystems harbour unique biodiversity because of their close interconnections with adjacent aquatic ecosystems. Yet, how aquatic ecosystems influence terrestrial biodiversity over different spatial scales is poorly understood, particularly in the tropics. We conducted field campaigns to collect 235 terrestrial invertebrate assemblages along 150 m transects from 47 streams in both Brazil and the UK, compiling one of the largest known datasets of riparian invertebrate community composition at multiple spatial scales. Invertebrate densities increased towards water in both regions. In Brazil, this was driven by an increase in spiders, with a corresponding decrease in non-predators, resulting in higher predator : prey ratios near water. In the UK, non-predator densities increased towards water, decreasing predator : prey ratios. While pairwise dissimilarity increased with distance from water in both regions, β-diversity was significantly higher in tropical assemblages, with more β-diversity explained by turnover. Spider community composition was significantly structured by distance from water in the Brazilian sites, suggesting tropical assemblages were influenced more by emerging aquatic prey, with a distinct spider community replacing other predators, with possible top-down control of terrestrial prey. High turnover-driven dissimilarity among tropical assemblages suggests that Brazilian riparian ecosystems are better managed at the landscape scale, with an emphasis on in-stream measures preventing disruption of aquatic resource subsidies.
河岸生态系统因其与相邻水生生态系统的紧密联系而拥有独特的生物多样性。然而，水生生态系统如何在不同空间尺度上影响陆地生物多样性却鲜为人知，尤其是在热带地区。我们开展了实地考察，沿着巴西和英国47条溪流的150米样带收集了235个陆地无脊椎动物群落，编制了已知最大的多空间尺度河岸无脊椎动物群落组成数据集之一。两个地区的无脊椎动物密度均朝着水体方向增加。在巴西，这是由蜘蛛数量增加驱动的，非捕食者数量相应减少，导致靠近水体处的捕食者与猎物比例更高。在英国，非捕食者密度朝着水体方向增加，捕食者与猎物比例降低。虽然两个地区的成对差异均随着与水体距离的增加而增大，但热带群落的β多样性显著更高，且更多的β多样性由周转率解释。在巴西的采样点，蜘蛛群落组成明显受与水体距离的影响，这表明热带群落更多地受到新兴水生猎物的影响，一个独特的蜘蛛群落取代了其他捕食者，可能对陆地猎物产生自上而下的控制。热带群落之间由周转率驱动的高差异表明，巴西河岸生态系统在景观尺度上需要更好地管理，重点是采取河流内措施防止水生资源补贴受到干扰。
