Kaspari Michael, Weiser Michael D, Siler Cameron D, Marshall Katie E, Smith Sierra N, Stroh Katherine M, de Beurs Kirsten M
Geographical Ecology Group, Department of Biology University of Oklahoma Norman Oklahoma USA.
Conservation Ecology Center Smithsonian's National Zoo and Conservation Biology Institute Front Royal Virginia USA.
Ecol Evol. 2024 Mar 13;14(3):e10856. doi: 10.1002/ece3.10856. eCollection 2024 Mar.
Nonnative species are a key agent of global change. However, nonnative invertebrates remain understudied at the community scales where they are most likely to drive local extirpations. We use the North American NEON pitfall trapping network to document the number of nonnative species from 51 invertebrate communities, testing four classes of drivers. We sequenced samples using the eDNA from the sample's storage ethanol. We used AICc informed regression to evaluate how native species richness, productivity, habitat, temperature, and human population density and vehicular traffic account for continent-wide variation in the number of nonnative species in a local community. The percentage of nonnatives varied 3-fold among habitat types and over 10-fold (0%-14%) overall. We found evidence for two types of constraints on nonnative diversity. Consistent with Capacity rules (i.e., how the number of niches and individuals reflect the number of species an ecosystem can support) nonnatives increased with existing native species richness and ecosystem productivity. Consistent with Establishment Rules (i.e., how the dispersal rate of nonnative propagules and the number of open sites limits nonnative species richness) nonnatives increased with automobile traffic-a measure of human-generated propagule pressure-and were twice as common in pastures than native grasslands. After accounting for drivers associated with a community's ability to support native species (native species richness and productivity), nonnatives are more common in communities that are regularly seasonally disturbed (pastures and, potentially deciduous forests) and those experiencing more vehicular traffic. These baseline values across the US North America will allow NEON's monitoring mission to document how anthropogenic change-from disturbance to propagule transport, from temperature to trends in local extinction-further shape biotic homogenization.
外来物种是全球变化的关键因素。然而,外来无脊椎动物在最有可能导致当地物种灭绝的群落尺度上仍未得到充分研究。我们利用北美NEON陷阱诱捕网络记录了51个无脊椎动物群落中外来物种的数量,测试了四类驱动因素。我们使用样本储存乙醇中的环境DNA对样本进行测序。我们使用基于AICc的回归分析来评估本地物种丰富度、生产力、栖息地、温度、人口密度和车辆交通如何解释当地群落中外来物种数量在大陆范围内的变化。外来物种的比例在不同栖息地类型之间相差3倍,总体上超过10倍(从0%到14%)。我们发现了对外来物种多样性的两种限制类型的证据。与容量规则一致(即生态位和个体数量如何反映生态系统能够支持的物种数量),外来物种随着现有本地物种丰富度和生态系统生产力的增加而增加。与定殖规则一致(即外来繁殖体的扩散速率和开放位点的数量如何限制外来物种丰富度),外来物种随着汽车交通量(一种人为产生的繁殖体压力衡量指标)的增加而增加,并且在牧场中的数量是原生草原的两倍。在考虑了与群落支持本地物种能力相关的驱动因素(本地物种丰富度和生产力)之后,外来物种在经常受到季节性干扰的群落(牧场以及可能的落叶林)和车辆交通较多的群落中更为常见。北美美国各地的这些基线值将使NEON的监测任务能够记录人为变化——从干扰到繁殖体运输,从温度到局部灭绝趋势——如何进一步塑造生物同质化。