Incidental Oligotrophication of North American Great Lakes
Incidental Oligotrophication of North American Great Lakes
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DOI：
10.1021/es103892w
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发表时间：
2011-04-15
影响因子：
11.4
通讯作者：
Scavia, Donald
中科院分区：
文献类型：
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作者：
Evans, Mary Anne;Fahnenstiel, Gary;Scavia, Donald
浮游植物的生产是决定生态系统稳定性以及生态系统产品和服务提供的重要因素。广阔且具有重要经济意义的北美五大湖承受着多种压力，了解它们对这些压力的反应对于理解全系统的生态控制非常重要。在这里，我们显示了 1983 年至 2008 年间，密歇根湖和休伦湖（美国和加拿大水域）所有流域的春季二氧化硅浓度（主要硅藻生长减少的指标）逐渐增加。这些变化表明，这些湖泊已经经历了逐渐的贫营养化，这与营养管理实施的同时和预期是一致的。二氧化硅（季节性浮游植物产量的代表）的季节性下降也发生了缓慢下降，直到最近几年，全湖的反应被突然下降所打断，使它们处于贫营养湖的范围内。产量急剧下降的时间与每个盆地的入侵性德莱森贻贝（尤其是斑驴贻贝）数量的扩张同时发生。营养物减少和入侵物种扩张的综合效应表明了大规模生态系统面临的挑战，并表明需要针对大型生态系统建立新的管理制度。
Phytoplankton production is an important factor in determining both ecosystem stability and the provision of ecosystem goods and services. The expansive and economically important North American Great Lakes are subjected to multiple stressors and understanding their responses to those stresses is important for understanding system-wide ecological controls. Here we show gradual increases in spring silica concentration (an indicator of decreasing growth of the dominant diatoms) in all basins of Lakes Michigan and Huron (USA and Canadian waters) between 1983 and 2008. These changes indicate the lakes have undergone gradual oligotrophication coincident with and anticipated by nutrient management implementation. Slow declines in seasonal drawdown of silica (proxy for seasonal phytoplankton production) also occurred, until recent years, when lake-wide responses were punctuated by abrupt decreases, putting them in the range of oligotrophic Lake Superior. The timing of these dramatic production drops is coincident with expansion of populations of invasive dreissenid mussels, particularly quagga mussels, in each basin. The combined effect of nutrient mitigation and invasive species expansion demonstrates the challenges facing large-scale ecosystems and suggest the need for new management regimes for large ecosystems.