Data from: Exposing the structure of an Arctic food web

How food webs are structured has major implications for their stability and dynamics. While poorly studied to date, arctic food webs are commonly assumed to be simple in structure, with few links per species. If this is the case, then different parts of the web may be weakly connected to each other, with populations and species united by only a low number of links. We provide the first highly resolved description of trophic link structure for a large part of a high-arctic food web. For this purpose, we apply a combination of recent techniques to describing the links between three predator guilds (insectivorous birds, spiders, and lepidopteran parasitoids) and their two dominant prey orders (Diptera and Lepidoptera). The resultant web shows a dense link structure and no compartmentalization or modularity across the three predator guilds. Thus, both individual predators and predator guilds tap heavily into the prey community of each other, offering versatile scope for indirect interactions across different parts of the web. The current description of a first but single arctic web may serve as a benchmark toward which to gauge future webs resolved by similar techniques. Targeting an unusual breadth of predator guilds, and relying on techniques with a high resolution, it suggests that species in this web are closely connected. Thus, our findings call for similar explorations of link structure across multiple guilds in both arctic and other webs. From an applied perspective, our description of an arctic web suggests new avenues for understanding how arctic food webs are built and function and of how they respond to current climate change. It suggests that to comprehend the community-level consequences of rapid arctic warming, we should turn from analyses of populations, population pairs, and isolated predator–prey interactions to considering the full set of interacting species.

食物网（food web）的结构模式对其稳定性与动态特征具有重要影响。尽管迄今相关研究仍较为匮乏，但学界通常认为高北极（high-arctic）食物网结构较为简单，每个物种种间连接数偏少。若这一假设成立，则食物网的不同区域间可能仅存在微弱连接，种群与物种之间仅通过少量种间关联维系。
本研究首次对高北极区域内大片范围的食物网营养连接结构（trophic link structure）进行了高分辨率解析。为此，我们结合多种新兴技术，对三类捕食者功能群（predator guild）——食虫鸟类、蜘蛛以及鳞翅目寄生蜂（lepidopteran parasitoids）——与其两大优势猎物类群双翅目（Diptera）与鳞翅目（Lepidoptera）之间的种间连接进行了系统刻画。
所构建的食物网呈现出密集的连接结构，且在这三类捕食者功能群间未表现出分区化（compartmentalization）或模块化（modularity）特征。由此可见，无论是单个捕食者还是捕食者功能群，均广泛利用彼此的猎物群落，为食物网不同区域间的间接相互作用提供了多样的潜在路径。
尽管本研究仅完成了首个北极食物网的解析工作，但该结果可作为基准参照，用于衡量后续采用同类技术开展的食物网研究。本研究针对覆盖范围较广的捕食者功能群展开，并采用了高分辨率实验技术，结果表明该食物网中的物种间联系十分紧密。因此，本研究结果呼吁，未来需针对北极及其他区域的食物网，开展针对多类功能群的食物网连接结构类似研究。
从应用视角来看，本研究对北极食物网的解析，为理解北极食物网的构建模式、运行机制以及其对当前气候变化的响应提供了全新研究路径。这表明，若要理解北极快速变暖所带来的群落级生态效应，我们需跳出仅针对种群、种群对以及孤立捕食者-猎物相互作用的分析框架，转而考量所有相互作用的物种集合。