Network structure and robustness of marine food webs
Network structure and robustness of marine food webs
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DOI：
10.3354/meps273291
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发表时间：
2004-01-01
影响因子：
2.5
通讯作者：
Martinez, ND
中科院分区：
文献类型：
--
作者：
Dunne, JA;Williams, RJ;Martinez, ND
先前的研究表明，食物网理论尚未解释海洋与其他类型生态系统食物网特性的重大差异。我们通过分析美国东北部大陆架、加勒比珊瑚礁和南非附近的本格拉的食物网网络结构来研究这个问题。这些海洋网的连接度（每个物种的链接数 (2)）、链接密度（每个物种的链接数）、平均链长以及中间类、杂食类和同类相食类群的分数有些高，但仍在其他网中观察到的范围内。我们通过使用经经验证实的“生态位模型”进一步比较了海洋网，该模型解释了观察到的多样性（分类群数量）和复杂性（连接性）的变化。我们的结果证实了之前报道的河口、淡水和陆地数据集的结果，这表明来自具有不同多样性和复杂性的不同类型生态系统的食物网具有共同的基本结构和排序特征。对物种丧失造成的潜在二次灭绝的分析表明，海洋食物网的结构稳健性也与其他食物网的趋势一致。正如预期的那样，鉴于海洋食物网的相关性相对较高，海洋食物网对于大多数相关类群和随机类群的损失似乎相当稳健。尽管如此，海洋类群之间的平均路径长度较短（1.6 个链接）表明，过度捕捞等扰动的影响可以在整个海洋生态系统中传播得比以前想象的更广泛。
Previous studies suggest that food-web theory has yet to account for major differences in food-web properties of marine versus other types of ecosystems. We examined this issue by analyzing the network structure of food webs for the Northeast US Shelf, a Caribbean reef, and Benguela, off South Africa. The values of connectance (links per species(2)), link density (links per species), mean chain length, and fractions of intermediate, omnivorous, and cannibalistic taxa of these marine webs are somewhat high but still within the ranges observed in other webs. We further compared the marine webs by using the empirically corroborated 'niche model' that accounts for observed variation in diversity (taxon number) and complexity (connectance). Our results substantiate previously reported results for estuarine, fresh-water, and terrestrial datasets, which suggests that food webs from different types of ecosystems with variable diversity and complexity share fundamental structural and ordering characteristics. Analyses of potential secondary extinctions resulting from species loss show that the structural robustness of marine food webs is also consistent with trends from other food webs. As expected, given their relatively high connectance, marine food webs appear fairly robust to loss of most connected taxa as well as random taxa. Still, the short average path length between marine taxa (1.6 links) suggests that effects from perturbations, such as over-fishing, can be transmitted more widely throughout marine ecosystems than previously appreciated.