Hallam Jane, Harris Nyeema C
Applied Wildlife Ecology Lab, Yale School of the Environment, Yale University, New Haven, Connecticut, USA.
J Anim Ecol. 2025 Aug;94(8):1587-1602. doi: 10.1111/1365-2656.70082. Epub 2025 Jun 17.
Urban ecosystems are expanding rapidly, significantly altering natural landscapes and impacting biodiversity. Here we explore seasonal variation in mammal diversity using environmental DNA (eDNA) from soil samples collected during winter and summer across 21 urban parks in Detroit, Michigan. We estimated gamma (regional), alpha (local) and beta (compositional change) diversity to determine if seasonal shifts, reflecting winter scarcity and summer abundance in mammal community composition and human activity, could be detected using eDNA. We expected that larger parks would exhibit greater diversity and higher seasonal turnover, consistent with the species-area relationship (SAR) and hypothesised that increased summer resource availability would lead to decreased network density as species disperse more broadly. We found that urban parks show subtle, park-specific changes in community composition influenced by both ecological and anthropogenic factors, with species including striped skunk, brown rat and groundhog responsible for the observed seasonal variation. Consistent with the SAR, larger parks supported higher species richness and diversity. Ecological network analysis, focusing on metrics such as clustering coefficient and network density, revealed a decrease in the overall connectivity and cohesiveness of species interactions from winter to summer, supporting our hypothesis of broader species dispersal during resource-rich periods. Notably, human DNA was prevalent in all parks, alongside detections of pig and cow eDNA, potentially reflecting human disturbance and anthropogenic food inputs. Our findings underscore the efficacy of eDNA analysis in capturing urban mammal community dynamics, the impact of human activities on biodiversity and its potential as a valuable tool for urban ecological research. Ultimately, enhancing monitoring capacity aids in conservation and urban planning efforts that will promote human-wildlife coexistence and preserve the socio-ecological benefits stemming from biodiversity across cityscapes.
城市生态系统正在迅速扩张，极大地改变了自然景观并影响生物多样性。在此，我们利用密歇根州底特律市21个城市公园冬季和夏季采集的土壤样本中的环境DNA（eDNA），探索哺乳动物多样性的季节变化。我们估计了伽马（区域）、阿尔法（局部）和贝塔（组成变化）多样性，以确定是否能利用eDNA检测到反映哺乳动物群落组成和人类活动中冬季稀缺和夏季丰富的季节变化。我们预计较大的公园会表现出更高的多样性和更高的季节周转率，这与物种 - 面积关系（SAR）一致，并假设夏季资源可用性增加会导致网络密度降低，因为物种分布更广泛。我们发现城市公园在群落组成上呈现出受生态和人为因素影响的细微、特定于公园的变化，条纹臭鼬、褐家鼠和土拨鼠等物种导致了观察到的季节变化。与物种 - 面积关系一致，较大的公园支持更高的物种丰富度和多样性。聚焦于聚类系数和网络密度等指标的生态网络分析表明，从冬季到夏季物种相互作用的整体连通性和凝聚力下降，支持了我们关于在资源丰富时期物种分布更广泛的假设。值得注意的是，人类DNA在所有公园中都很普遍，同时还检测到猪和牛的eDNA，这可能反映了人类干扰和人为食物输入。我们的研究结果强调了eDNA分析在捕捉城市哺乳动物群落动态、人类活动对生物多样性的影响以及其作为城市生态研究有价值工具的潜力方面的有效性。最终，加强监测能力有助于保护和城市规划工作，促进人类与野生动物共存，并保护城市景观中生物多样性带来的社会生态效益。
