Oceanographic and climatic variation drive top-down/bottom-up coupling in the Galapagos intertidal meta-ecosystem
Oceanographic and climatic variation drive top-down/bottom-up coupling in the Galapagos intertidal meta-ecosystem
复制标题
海洋和气候变化驱动加拉帕戈斯潮间带元生态系统自上而下/自下而上的耦合
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
D. Palacios
中科院分区：
文献类型：
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作者：
L. Vinueza;B. Menge;Diego Javier Ruiz Jarrin;D. Palacios
在不同的海洋环境下，草食动物对初级生产者的影响是一个引起强烈生态兴趣的问题，因为它们的丰度、捕食者的丰度以及营养循环和气候模式的拟人化改变正在发生变化。在温带岩石海岸、珊瑚礁、红树林和盐沼中，已经研究了海洋栖息地中生产力和草食之间的相互作用，但在热带纬度的研究较少。为了确定草食藻类动态如何随海洋学制度而变化，我们于2006年1月至2009年1月在加拉帕戈斯群岛的岩石潮间带群落中采用了比较实验方法。之所以选择这一设置，是因为在以下范围内发生了强烈对比的海洋条件；181公里，在温度、营养、浮游植物生产力和潮间带群落以及包括海鬣蜥在内的大量大型食草动物方面存在显著差异。在以低、中、高自下而上输入为特征的三种海洋学制度中的每一种制度的两个地点进行了实验和测量。在低投入的地点，大型食草动物（鱼、蟹、鬣蜥）具有一致的自上而下效应，减少了藻类的丰度，并留下了一些抗食草动物的品种。在中高投入点，La Ni ~ na（冷期）对消费者的影响大于El Ni ~ no（暖期）。在高投入的地点，藻类生物量自然相对较高，并以可食用藻类Ulva spp为主。大型食草动物减少了藻类生物量，但它们的主要影响是间接的，因为在它们缺席的情况下，珊瑚取代了其他种类的藻类。热带地区先前的结果揭示了自上而下的相互作用和招募在潮间带群落结构中的主导作用。我们的研究结果表明，当考虑到更广泛的海洋情景时，自上而下和自下而上的作用力的相对重要性取决于环境，并随海洋状况和气候变率而变化。
The impact of herbivores on primary producers in differing oceanographic regimes is a matter of intense ecological interest due to ongoing changes in their abundance, that of their predators, and anthropomorphic alteration of nutrient cycles and climatic patterns. Interactions between productivity and herbivory in marine habitats have been studied on temperate rocky shores, coral reefs, mangroves, and salt marshes, but less so at tropical latitudes. To determine how herbivore-alga dynamics varied with oceanographic regime, we used the comparative-experimental approach in rocky intertidal communities on the Galapagos Islands from January 2006 to January 2009. This setting was selected because strongly contrasting oceanographic conditions occurred within a range of ;181 km, with significant differences in temperature, nutrients, phytoplankton productivity, and intertidal communities, and in abundance of macro-herbivores, including marine iguanas. Experiments and measurements were conducted at two sites in each of three oceanographic regimes characterized by low, intermediate, and high bottom-up inputs. At sites of low inputs, macro- herbivores (fish, crabs, iguanas) had a consistent top-down effect, reducing algal abundance, and leaving a few grazer-resistant varieties. At sites of intermediate and high inputs, consumer impacts were stronger during La Ni˜ na (cool phase) than during El Ni˜ no (warm phase). At sites of high inputs, algal biomass was naturally relatively high and was dominated by the edible algae Ulva spp. Macro-grazers reduced algal biomass, but their primary effect was indirect, as articulated corallines displaced other species of algae in their absence. Prior results from the tropics had revealed dominant effects of top-down interactions and recruitment in structuring intertidal communities. Our results suggest that, when a broader oceanographic scenario is taken into account, the relative importance of top-down and bottom-up forces are context dependent, varying with oceanographic regime and climatic variability.
影响因子：
56.9
作者：
Harvell, CD;Kim, K;Vasta, GR
通讯作者：
Vasta, GR