Above- and below-ground impacts of introduced predators in seabird-dominated island ecosystems
Above- and below-ground impacts of introduced predators in seabird-dominated island ecosystems
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DOI：
10.1111/j.1461-0248.2006.00983.x
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发表时间：
2006-12-01
期刊：
影响因子：
8.8
通讯作者：
Williamson, Wendy M.
中科院分区：
文献类型：
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作者：
Fukami, Tadashi;Wardle, David A.;Williamson, Wendy M.
捕食者经常在陆地生态系统中发挥多营养级联效应。然而，这种捕食如何间接影响地上和地下生物群之间的相互作用却知之甚少，尽管这些相互作用具有重要的功能。对新西兰近海岛屿没有老鼠和老鼠入侵的比较表明，引入的老鼠捕食海鸟，扰乱了海鸟从海到陆地的养分运输，从而降低了森林土壤肥力，而肥力下降反过来又对地下生物及其驱动的生态系统过程产生了广泛的级联效应。我们的数据进一步表明，对地下食物网的一些影响可归因于地上植物养分和生物量的变化，这本身与入侵岛屿上土壤干扰和肥力的减少有关。这些结果表明，通过破坏整个生态系统的营养补贴，捕食者可以通过多种途径间接地诱导地上和地下生物群的强烈转变，并在这样做的过程中，充当主要的生态系统驱动因素。
Predators often exert multi-trophic cascading effects in terrestrial ecosystems. However, how such predation may indirectly impact interactions between above- and below-ground biota is poorly understood, despite the functional importance of these interactions. Comparison of rat-free and rat-invaded offshore islands in New Zealand revealed that predation of seabirds by introduced rats reduced forest soil fertility by disrupting sea-to-land nutrient transport by seabirds, and that fertility reduction in turn led to wide-ranging cascading effects on belowground organisms and the ecosystem processes they drive. Our data further suggest that some effects on the belowground food web were attributable to changes in aboveground plant nutrients and biomass, which were themselves related to reduced soil disturbance and fertility on invaded islands. These results demonstrate that, by disrupting across-ecosystem nutrient subsidies, predators can indirectly induce strong shifts in both above- and below-ground biota via multiple pathways, and in doing so, act as major ecosystem drivers.