Nutrient limitation in detritus-based microcosms in Sarracenia purpurea
Nutrient limitation in detritus-based microcosms in Sarracenia purpurea
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DOI：
10.1007/s10750-006-0265-2
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发表时间：
2006-12-01
期刊：
影响因子：
2.6
通讯作者：
Daufresne, Tanguy
中科院分区：
文献类型：
--
作者：
Gray, Sarah M.;Miller, Thomas E.;Daufresne, Tanguy
大多数先前的工作，自上而下和自下而上的影响在水生生物群落的作用，忽略了重要的碎屑成分，发生在自然系统中。我们调查了特定的营养物质（碳，磷和氮），以及顶级捕食者（蚊子Wyeomyia smithii）的影响，对食虫群落的结构发现在充满水的叶片的猪笼草紫瓶子草。三种营养物质的浓度和捕食者的存在进行了操纵的析因设计，而其余的社区的响应进行了量化。细菌的生长被发现是强烈的碳限制，有点少限制磷和有两种营养素的影响之间的相互作用。无论是碳或磷添加影响原生动物或轮虫丰度，氮只有轻微的影响。然而，捕食者的存在，显着减少了丰富的四个数字占主导地位的食菌动物。自上而下和自下而上的影响之间没有相互作用;相邻营养级之间强烈的直接相互作用似乎随着它们在食物链中向上或向下传播而大大减弱。
Most prior work on the role of top-down and bottom-up effects in aquatic communities has ignored the significant detrital component that occurs in natural systems. We investigated the effects of specific nutrients (carbon, phosphorus, and nitrogen), as well as a top predator (the mosquito Wyeomyia smithii), on the structure of the detritivore community found in the water-filled leaves of the pitcher plant Sarracenia purpurea. The concentrations of three nutrients and the presence of the predators were manipulated in a factorial design, while the response of the remaining community was quantified. Bacterial growth was found to be strongly carbon-limited and somewhat less limited by phosphorus and there was an interaction between the effects of the two nutrients. Neither carbon or phosphorus addition affected protozoan or rotifer abundance, and nitrogen had only a minor effect. The presence of the predator, however, significantly reduced the abundance of the four numerically dominant bacteriovores. There were no interactions between top-down and bottom-up effects; the strong direct reciprocal effects between adjacent trophic levels seem to be greatly attenuated as they are propagated farther up or down the food chain.