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阿波普卡(Apopka)湖位于佛罗里达中北部,是一个富营养化的浅水湖泊。1947年,湖泊的初级生产群落结构(PPCS)发生了巨大的变化。在1947年,水下的水生植物被飓风连根拔起,并在数周之内被浮游植物所替代,初级生产群落结构发生了突然演替。在此我们提出两个假设解释群落结构向浮游植物的突然演替。首先,流域在19世纪初后期的水文变化使湖泊的水位大约下降了1.0m,从而使生态系统通过大型植物群落生产力提高适应了中等的、人为的营养物质富集的环境。第二,开始于1942年的泛滥平原湿地的水文变化和大规模的农业发展,改变了湖泊中磷载荷的模式和规模,引起了1947年浮游植物占优势的突然变化。历史上土地利用变化和古湖泊在营养物的生物响应数据方面也支持这些假设。
Apopka Lake is an eutrophic shallow lake located in north-central Florida. In 1947, the lake’s primary production community structure (PPCS) changed dramatically. In 1947, underwater aquatic plants were uprooted by hurricanes and replaced by phytoplankton within a few weeks, with a sudden succession of primary production community structures. Here we propose two hypotheses to explain the sudden succession of community structure to phytoplankton. First, hydrological changes in the basin in the late 1800s reduced the lake’s water level by about 1.0 m, allowing ecosystems to adapt to medium, man-made nutrient-rich environments through increased plant community productivity. Second, the hydrological changes and large-scale agricultural development of flood plain wetlands that began in 1942 changed the pattern and scale of phosphorus loading in lakes and caused a sudden change in phytoplankton dominance in 1947. These assumptions are also supported by historical land-use changes and ancient lakes in nutrient response data on nutrients.