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.食物网的结构模式对其稳定性与动态特征具有重要影响。尽管北极食物网迄今尚未得到充分研究，但学界通常认为其结构较为简单，每个物种种间连接数较少。若这一假设成立，则食物网的不同区域间连接程度可能较弱，种群与物种之间仅依靠少量连接维系关联。本研究首次对高纬度北极地区食物网的大部分区域开展了营养连接结构的高分辨率解析与描述。为此，本研究结合多项前沿技术，对三类捕食者功能群——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）和鳞翅目（Lepidoptera）之间的营养连接进行了刻画。所构建的食物网呈现出密集的连接结构，且在三类捕食者功能群之间未出现分区化或模块化特征。因此，无论是单个捕食者还是捕食者功能群，均大量利用彼此的猎物群落，为食物网不同区域间的间接互作提供了广泛的可能。尽管本研究仅针对单个北极食物网开展了首次解析，但其描述结果可作为基准，用于评估后续采用同类技术解析的北极食物网研究。本研究覆盖了异常广泛的捕食者功能群，并采用了高分辨率的研究技术，结果表明该食物网中的物种间关联十分紧密。因此，本研究结果呼吁，针对北极及其他区域的食物网，均应开展覆盖多类功能群的营养连接结构探索。从应用研究角度来看，本研究对北极食物网的解析为理解北极食物网的构建机制、运行模式以及其对当前气候变化的响应提供了新的研究方向。这表明，若要理解北极快速变暖所带来的群落层面影响，我们需从原本针对种群、种群对以及孤立捕食者-猎物互作的分析，转向考量所有互作物种的整体网络关系。