Specialization, constraints, and conflicting interests in mutualistic networks
Specialization, constraints, and conflicting interests in mutualistic networks
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DOI：
10.1016/j.cub.2006.12.039
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发表时间：
2007-02-20
期刊：
影响因子：
9.2
通讯作者：
Bluethgen, Nils
中科院分区：
文献类型：
--
作者：
Bluethgen, Nico;Menzel, Florian;Bluethgen, Nils
生态相互作用网络的拓扑结构为共同进化、生物多样性和生态系统稳定性理论提供了重要信息[1-6]。然而，大多数先前的网络分析仅计算链接数量，而忽略了链接强度的变化。由于这种粗略的分辨率，结果会随着规模和采样强度的变化而变化，从而阻碍了不同级别网络模式的比较[7-9]。我们将最近开发的 [10] 基于信息论的定量和与尺度无关的分析应用于 51 个互惠植物-动物网络，以相互作用频率作为链接强度的度量。大多数网络都是高度结构化的，明显偏离随机关联。专业化程度与网络规模无关。授粉网比种子传播网更加专门化，专性共生的蚂蚁与植物的互利共生比花蜜介导的兼性共生更加专门化。在整个网络中，动物和植物的平均专业化是相关的，但受到所涉及的植物与动物物种的比例的限制。在授粉网络中，很少访问的植物平均比经常访问的植物更加专业化，而传粉者的专业化与其相互作用频率呈正相关。我们得出的结论是，生态社区的定量专业化反映了网络架构的进化权衡和限制。这种方法可以很容易地扩展到其他类型的生物相互作用。
The topology of ecological interaction webs holds important information for theories of coevolution, biodiversity, and ecosystem stability [1-6]. However, most previous network analyses solely counted the number of links and ignored variation in link strength. Because of this crude resolution, results vary with scale and sampling intensity, thus hampering a comparison of network patterns at different levels [7-9]. We applied a recently developed [10] quantitative and scale-independent analysis based on information theory to 51 mutualistic plant-animal networks, with interaction frequency as measure of link strength. Most networks were highly structured, deviating significantly from random associations. The degree of specialization was independent of network size. Pollination webs were significantly more specialized than seed-dispersal webs, and obligate symbiotic ant-plant mutualisms were more specialized than nectar-mediated facultative ones. Across networks, the average specialization of animal and plants was correlated, but is constrained by the ratio of plant to animal species involved. In pollination webs, rarely visited plants were on average more specialized than frequently attended ones, whereas specialization of pollinators was positively correlated with their interaction frequency. We conclude that quantitative specialization in ecological communities mirrors evolutionary trade-offs and constraints of web architecture. This approach can be easily expanded to other types of biological interactions.