Strong top-down control in southern California kelp forest ecosystems
Strong top-down control in southern California kelp forest ecosystems
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DOI：
10.1126/science.1128613
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发表时间：
2006-05-26
期刊：
影响因子：
56.9
通讯作者：
Broitman, BR
中科院分区：
文献类型：
--
作者：
Halpern, BS;Cottenie, K;Broitman, BR
通过陆地径流进入海洋生态系统的人类营养物质输入的全球规模变化，加上通过捕鱼广泛消除捕食者，使理解自上而下与自下而上控制食物网动态的相对作用变得更加紧迫。然而，最近对海洋生态系统中的群落调节进行的大规模研究显示出截然不同的结果，这一问题基本上没有得到解决。我们结合了一个多年的，大规模的数据集的46种海带森林从加州海峡群岛与卫星衍生的初级生产的物种丰度，发现自上而下的控制解释7- 10倍以上的差异丰富的底部和中间的营养水平比自下而上的控制。这种自上而下的控制传播通过各种物种水平的直接和间接的反应捕食者丰度。在沿海海洋生态系统中，特别是在海带森林系统中，管理捕鱼等自上而下的影响可能比通常认为的更重要。
Global-scale changes in anthropogenic nutrient input into marine ecosystems via terrestrial runoff, coupled with widespread predator removal via fishing, have created greater urgency for understanding the relative role of top-down versus bottom-up control of food web dynamics. Yet recent large-scale studies of community regulation in marine ecosystems have shown dramatically different results that leave this issue largely unresolved. We combined a multiyear, large-scale data set of species abundances for 46 species in kelp forests from the California Channel Islands with satellite-derived primary production and found that top-down control explains 7- to 10-fold more of the variance in abundance of bottom and mid-trophic levels than does bottom-up control. This top-down control was propagated via a variety of species-level direct and indirect responses to predator abundance. Management of top-down influences such as fishing may be more important in coastal marine ecosystems, particularly in kelp forest systems, than is commonly thought.