Changing Ecosystem Dynamics in the Laurentian Great Lakes: Bottom-Up and Top-Down Regulation
Changing Ecosystem Dynamics in the Laurentian Great Lakes: Bottom-Up and Top-Down Regulation
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DOI：
10.1093/biosci/bit001
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发表时间：
2014-01-01
期刊：
影响因子：
10.1
通讯作者：
Weidel, Brian C.
中科院分区：
文献类型：
--
作者：
Bunnell, David B.;Barbiero, Richard P.;Weidel, Brian C.
了解生态系统结构自上而下和自下而上调节的相对重要性是一个基本的生态问题，对渔业和水质管理具有影响。对于劳伦森五大湖，自 20 世纪 70 年代初以来，养分输入一直在减少，而顶级捕食者生物量却在增加，我们描述了多个营养级别的趋势，并探讨了其潜在驱动因素。我们的分析显示，自 1998 年以来，五个湖泊中至少有三个湖泊的水体透明度不断提高，浮游植物、本地无脊椎动物和被捕食鱼类数量减少。尽管每个湖至少在一对营养级上提供支持，但自下而上监管的证据在休伦湖最为有力。自上而下监管的证据很少。尽管非本土德莱森贻贝可能对养分循环和浮游植物产生巨大影响，但它们对较高营养水平的影响仍不确定。我们强调了监测和知识应提高对食物网动态的理解并促进基于生态系统的管理的实施的差距。
Understanding the relative importance of top-down and bottom-up regulation of ecosystem structure is a fundamental ecological question, with implications for fisheries and water-quality management. For the Laurentian Great Lakes, where, since the early 1970s, nutrient inputs have been reduced, whereas top-predator biomass has increased, we describe trends across multiple trophic levels and explore their underlying drivers. Our analyses revealed increasing water clarity and declines in phytoplankton, native invertebrates, and prey fish since 1998 in at least three of the five lakes. Evidence for bottom-up regulation was strongest in Lake Huron, although each lake provided support in at least one pair of trophic levels. Evidence for top-down regulation was rare. Although nonindigenous dreissenid mussels probably have large impacts on nutrient cycling and phytoplankton, their effects on higher trophic levels remain uncertain. We highlight gaps for which monitoring and knowledge should improve the understanding of food-web dynamics and facilitate the implementation of ecosystem-based management.