TOP-DOWN HERBIVORY AND BOTTOM-UP EL NIÑO EFFECTS ON GALÁPAGOS ROCKY-SHORE COMMUNITIES
TOP-DOWN HERBIVORY AND BOTTOM-UP EL NIÑO EFFECTS ON GALÁPAGOS ROCKY-SHORE COMMUNITIES
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自上而下的食草动物和自下而上的厄尔尼诺现象对加拉帕戈斯岩岸社区的影响
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
R. Bustamante
中科院分区：
文献类型：
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作者：
L. Vinueza;G. Branch;M. L. Branch;R. Bustamante
我们评估了海洋鬣蜥，萨利轻足蟹，鱼类对岩石海岸固着生物在两个地点在圣克鲁斯岛，加拉帕戈斯群岛，厄瓜多尔，3-5年期间和1997-1998年厄尔尼诺现象后，使用排除笼分离的影响。暴露于自然放牧的地块主要由结壳藻类或红藻草皮和关节珊瑚。藻类以下列方式对厄尔尼诺现象作出反应。在早期阶段，甲壳Gymnogongrus和/或红藻草皮占主导地位。在厄尔尼诺现象的中心，食草动物对藻类覆盖的影响有限，但对藻类的大小产生了重大影响。大多数藻类（特别是可食用的形式）是稀缺或下降，虽然温暖的水短命物种（特别是Giffordia mitchelliae）蓬勃发展，增加了多样性和过度生长的结壳。鬣蜥死亡率高，螃蟹密度低。当正常条件恢复时，暖水短命植物减少，螃蟹密度上升，食草动物有显着的，但网站s…
We evaluated the effects of marine iguanas, sally lightfoot crabs, and fish on rocky-shore sessile organisms at two sites at Santa Cruz Island, Galapagos Islands, Ecuador, for 3–5 years during and after the 1997–1998 El Nino, using exclusion cages to separate the effects. Plots exposed to natural grazing were dominated either by encrusting algae or by red algal turf and articulated corallines. Algae fluctuated in response to El Nino in the following way. During an early phase, crustose Gymnogongrus and/or red algal turf were dominant. In the heart of El Nino, grazers had limited effects on algal cover but influenced algal sizes substantially. Most algae (particularly edible forms) were scarce or declined, although warm-water ephemeral species (notably Giffordia mitchelliae) flourished, increasing diversity and overgrowing crusts. Iguana mortalities were high, and crab densities low. When normal conditions returned, warm-water ephemerals declined, crab densities rose, and grazers had significant but site-s...