Food web topology and parasites in the pelagic zone of a subarctic lake
Food web topology and parasites in the pelagic zone of a subarctic lake
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DOI：
10.1111/j.1365-2656.2008.01518.x
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发表时间：
2009-05-01
影响因子：
4.8
通讯作者：
Kuris, Armand M.
中科院分区：
文献类型：
--
作者：
Amundsen, Per-Arne;Lafferty, Kevin D.;Kuris, Armand M.
寄生虫以其复杂的生命周期渗透到营养网中，但很少有研究将寄生虫纳入食物网分析。在这里，我们提供了一个高分辨率的食物网从远洋区的亚北极湖泊，并探讨如何将寄生虫改变的拓扑结构的web.Parasites使用主机在所有的营养级和增加的食物链长度和营养级的总数。将它们纳入网络分析，使链接数量增加了一倍以上，并导致重要食物网特征（如链接密度和连接度）的增加。超过一半的寄生虫类群是营养传播的，在多个营养级上利用宿主，从而增加了营养网中杂食性的程度。寄生虫-宿主连接的数量与宿主种的连接密度呈正相关，而对于非营养性传播的寄生虫则没有这种关系。我们的研究结果表明，自由生活的物种的联系密度影响他们暴露于营养传播的寄生虫，这可能是更有可能采用高度连接的物种作为主机在复杂的生命周期的演变过程中，这项研究支持了一个突出的作用，寄生虫在生态网络，并表明，他们的纳入可能会大大改变考虑食物网的结构和功能。
Parasites permeate trophic webs with their often complex life cycles, but few studies have included parasitism in food web analyses. Here we provide a highly resolved food web from the pelagic zone of a subarctic lake and explore how the incorporation of parasites alters the topology of the web.Parasites used hosts at all trophic levels and increased both food-chain lengths and the total number of trophic levels. Their inclusion in the network analyses more than doubled the number of links and resulted in an increase in important food-web characteristics such as linkage density and connectance.More than half of the parasite taxa were trophically transmitted, exploiting hosts at multiple trophic levels and thus increasing the degree of omnivory in the trophic web.For trophically transmitted parasites, the number of parasite-host links exhibited a positive correlation with the linkage density of the host species, whereas no such relationship was seen for nontrophically transmitted parasites. Our findings suggest that the linkage density of free-living species affects their exposure to trophically transmitted parasites, which may be more likely to adopt highly connected species as hosts during the evolution of complex life cycles.The study supports a prominent role for parasites in ecological networks and demonstrates that their incorporation may substantially alter considerations of food-web structure and functioning.