Data from: Resource specialists lead local insect community turnover associated with temperature – analysis of an 18-year full-seasonal record of moths and beetles

Insect responses to recent climate change are well documented, but the role of resource specialization in determining species vulnerability remains poorly understood. Uncovering local ecological effects of temperature change with high-quality, standardized data provides an important first opportunity for predictions about responses of resource specialists, and long-term time series are essential in revealing these responses. Here, we investigate temperature-related changes in local insect communities, using a sampling site with more than a quarter-million records from two decades (1992–2009) of full-season, quantitative light trapping of 1543 species of moths and beetles. We investigated annual as well as long-term changes in fauna composition, abundance and phenology in a climate-related context using species temperature affinities and local temperature data. Finally, we explored these local changes in the context of dietary specialization. Across both moths and beetles, temperature affinity of specialists increased through net gain of hot-dwelling species and net loss of cold-dwelling species. The climate-related composition of generalists remained constant over time. We observed an increase in species richness of both groups. Furthermore, we observed divergent phenological responses between cold- and hot-dwelling species, advancing and delaying their relative abundance, respectively. Phenological advances were particularly pronounced in cold-adapted specialists. Our results suggest an important role of resource specialization in explaining the compositional and phenological responses of insect communities to local temperature increases. We propose that resource specialists in particular are affected by local temperature increase, leading to the distinct temperature-mediated turnover seen for this group. We suggest that the observed increase in species number could have been facilitated by dissimilar utilization of an expanded growing season by cold- and hot-adapted species, as indicated by their oppositely directed phenological responses. An especially pronounced advancement of cold-adapted specialists suggests that such phenological advances might help minimize further temperature-induced loss of resource specialists. Although limited to a single study site, our results suggest several local changes in the insect fauna in concordance with expected change of larger-scale temperature increases.昆虫对近期气候变化的响应已有大量文献记载，但资源特化（resource specialization）在决定物种脆弱性方面的作用仍不甚明晰。借助高质量、标准化数据揭示温度变化的局域生态效应，为预测资源特化物种的响应提供了重要的首次契机，而长期时间序列则是揭示这些响应的核心要素。本研究依托一处拥有20余年（1992—2009年）全季定量灯光诱捕数据的采样点——该数据集包含超过25万条记录，涵盖1543种蛾类与甲虫——探究了局域昆虫群落的温度相关变化。我们借助物种温度亲和性（species temperature affinities）与局域温度数据，从气候关联视角分析了动物群组成、多度及物候的年度与长期变化。最后，我们结合食性特化（dietary specialization）背景探讨了这些局域变化。在蛾类与甲虫类群中，特化物种的温度亲和性均随热栖物种的净迁入与冷栖物种的净丧失而提升。广适物种的气候相关组成随时间未发生显著变化。我们观察到两类群的物种丰富度均有所提升。此外，冷栖与热栖物种呈现出分化的物候响应：前者相对多度的峰值提前，后者则延迟。冷适应特化物种的物候提前尤为显著。研究结果表明，资源特化在解释昆虫群落在局域温度升高下的组成与物候响应中发挥着重要作用。我们提出，资源特化物种尤其易受局域温度升高的影响，这正是该类群出现显著温度介导的类群更替的原因。我们认为，观测到的物种数量增加，可能得益于冷适应与热适应物种对延长的生长季的差异化利用——这一点可从二者相反的物候响应得到印证。冷适应特化物种尤为显著的物候提前现象，提示这类物候前移或许有助于缓解温度升高进一步导致的资源特化物种丧失。尽管本研究仅局限于单个采样点，但其结果表明，局域昆虫动物群的若干变化与更大尺度温度升高的预期响应相一致。