Predator diversity strengthens trophic cascades in kelp forests by modifying herbivore behaviour
Predator diversity strengthens trophic cascades in kelp forests by modifying herbivore behaviour
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DOI：
10.1111/j.1461-0248.2005.00842.x
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发表时间：
2006-01-01
期刊：
影响因子：
8.8
通讯作者：
Thornber, CS
中科院分区：
文献类型：
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作者：
Byrnes, J;Stachowicz, JJ;Thornber, CS
尽管人类介导的灭绝对较高的营养级产生了不成比例的影响，但多样性下降对生态系统的影响对于植物和食草动物最为人所知。我们结合实地调查和实验操作来研究捕食者多样性变化对海带森林营养级联的影响。在实地调查中，我们发现捕食者多样性与草食动物丰度呈负相关，与海带丰度呈正相关。为了评估这种关系是否存在因果关系，我们操纵了海带中生态系统中的捕食者丰富度，发现捕食者丰富度的降低增加了草食动物的放牧，导致巨型海带巨囊藻的生物量减少。不同捕食者的存在导致不同的食草动物通过减少放牧来改变其行为，使得捕食者多样性最高时总放牧量最低。我们的研究结果表明，捕食者多样性的下降可能会减少关键栖息地物种的丰度，从而对群落结构产生连锁效应。
Although human-mediated extinctions disproportionately affect higher trophic levels, the ecosystem consequences of declining diversity are best known for plants and herbivores. We combined field surveys and experimental manipulations to examine the consequences of changing predator diversity for trophic cascades in kelp forests. In field surveys we found that predator diversity was negatively correlated with herbivore abundance and positively correlated with kelp abundance. To assess whether this relationship was causal, we manipulated predator richness in kelp mesocosms, and found that decreasing predator richness increased herbivore grazing, leading to a decrease in the biomass of the giant kelp Macrocystis. The presence of different predators caused different herbivores to alter their behaviour by reducing grazing, such that total grazing was lowest at highest predator diversity. Our results suggest that declining predator diversity can have cascading effects on community structure by reducing the abundance of key habitat-providing species.