Exposing the structure of an Arctic food web
Exposing the structure of an Arctic food web
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揭示北极食物网的结构
作者：
Helena Wirta;E. Vesterinen;P. Hambäck;E. Weingartner;C. Rasmussen;Jeroen Reneerkens;N. Schmidt;O. Gilg;T. Roslin
食物网的结构对其稳定性和动态具有重大影响。虽然迄今为止研究很少，但人们普遍认为北极食物网结构简单，每个物种之间的联系很少。如果是这种情况，那么网络的不同部分可能彼此之间的联系很弱，人口和物种仅通过少量的链接联系在一起。我们首次对大部分高纬度食物网的营养链结构进行了高度解析的描述。为此，我们结合使用最新技术来描述三个捕食者行会（食虫鸟类、蜘蛛和鳞翅目寄生蜂）与其两个主要猎物目（双翅目和鳞翅目）之间的联系。由此产生的网络显示出密集的链接结构，并且三个捕食者行会之间没有划分或模块化。因此，个体捕食者和捕食者行会都大力利用彼此的猎物社区，为跨网络不同部分的间接互动提供了多种范围。当前对第一个但单个北极网的描述可以作为衡量通过类似技术解决的未来网的基准。针对范围广泛的捕食者行会，并依靠高分辨率技术，它表明该网络中的物种是紧密相连的。因此，我们的研究结果要求对北极和其他网络中多个行会的链接结构进行类似的探索。从应用的角度来看，我们对北极食物网的描述为理解北极食物网的构建和运作方式以及它们如何应对当前的气候变化提供了新的途径。它表明，为了理解北极快速变暖对群落层面的影响，我们应该从对种群、种群对和孤立的捕食者与猎物相互作用的分析转向考虑全套相互作用的物种。
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.