Effects of benthivorous fish on biogeochemical processes in lake sediments
Effects of benthivorous fish on biogeochemical processes in lake sediments
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DOI：
10.1111/j.1365-2427.2006.01569.x
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发表时间：
2006-07
影响因子：
2.7
通讯作者：
A. Persson;J. Svensson
中科院分区：
文献类型：
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作者：
A. Persson;J. Svensson
1.水生环境的研究表明，社区组织可能会强烈影响生态系统的功能。一个常见的现象是，随着鱼类群落组成的变化，营养水平也随之变化。虽然已经提出了几种假设，但对于涉及哪些机制没有达成共识。我们的研究评估了底栖鱼类对沉积物-水界面生态地球化学过程的间接影响，分别从营养盐排泄或沉积物再悬浮引起的直接影响。2.我们分配到三个处理代表典型的池塘社区领域的外壳，没有鱼，除了大约10个小丁鱼或除了一个大的鲷。一个夏天后，我们监测了水化学，底栖无脊椎动物和附着生物的外壳和采样的沉积物芯的生化过程速率（沉积物和水之间的氧，磷和氮交换，反硝化速率）的实验室分析。3.鱼类对底栖无脊椎动物有较强的负效应，但对附着生物、沉积物有机质含量和孔隙度的影响较弱。此外，有显着的积极鱼类的影响，在水中的磷和氮的浓度。然而，没有一般的处理效果的沉积物过程，可以解释的处理效果的水化学的外壳。4.因此，总体治疗效应沿相互作用链沿着减弱。我们的结论是，所观察到的底栖鱼类对水化学的影响可能是因为直接影响营养排泄或沉积物的再悬浮。鲷和丁鲷治疗之间的相似性表明大生态位的互补性，尽管他们不同的栖息地偏好。（减）
1. Studies of aquatic environments have shown that community organisation may strongly affect ecosystem functioning. One common phenomenon is a change in nutrient level following a shift in the fish community composition. Although several hypotheses have been suggested, there is no consensus on which mechanisms are involved. Our study evaluated indirect effects of benthivorous fish on the biogeochemical processes at the sediment-water interface separately from direct effects caused by nutrient excretion or sediment resuspension. 2. We assigned field enclosures to three treatments representing typical pond communities; without fish, addition of approximately 10 small tench or addition of one large bream. After one summer, we monitored the water chemistry, benthic invertebrates and periphyton in the enclosures and sampled sediment cores for laboratory analysis of biochemical process rates (oxygen, phosphorus and nitrogen exchange between sediment and water, and denitrification rate). 3. Fish had strong negative effects on benthic invertebrates, but weaker effects on periphyton, organic content and porosity of the sediment. Moreover, there were significant positive fish effects on both phosphorus and nitrogen concentrations in the water. However, there were no general treatment effects on sediment processes that could explain the treatment effects on water chemistry in the enclosures. 4. Hence, overall treatment effects attenuated along the chain of interactions. We conclude that the observed effect of benthic fish on water chemistry was probably because of direct effects on nutrient excretion or resuspension of sediment. The similarity between bream and tench treatments suggests large niche complementarity despite their different habitat preferences. (Less)