Tonle Sap lake-river floodplain ecosystem (TSE) is one of the world’s most productive freshwater systems. Changes in hydrology, climate, population density, and land use influence water quality in this system. We investigated long term water quality dynamics (22 years) in space and time and identified potential changes in nutrient limitation based on nutrient ratios of inorganic nitrogen and phosphorus. Water quality was assessed at five sites highlighting the dynamics in wet and dry seasons. Predictors of water quality included watershed land use, climate, population, and water level. Most water quality parameters varied across TSE, except pH and nitrate that remained constant at all sites. In the last decade, there is a change in the chemical nutrient ratio suggesting that nitrogen may be the primary limiting nutrient across the system. Water quality was strongly affected by development in the watershed i.e., flooded forest loss, climatic variation, population growth, and change in water level. Seasonal variations of water quality constituents were driven by precipitation and hydrology, notably the Mekong’s distinct seasonal flood pulse.

中文翻译：

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洞里萨生态系统水质动态的空间和长期时间变化

洞里萨湖河泛滥平原生态系统 (TSE) 是世界上生产力最高的淡水系统之一。水文、气候、人口密度和土地利用的变化会影响该系统中的水质。我们调查了空间和时间的长期水质动态（22 年），并根据无机氮和磷的养分比率确定了养分限制的潜在变化。在五个地点评估了水质，突出了雨季和旱季的动态。水质的预测因素包括流域土地利用、气候、人口和水位。除了所有地点的 pH 值和硝酸盐保持不变外，TSE 的大多数水质参数都不同。在过去十年中，化学养分比例发生了变化，表明氮可能是整个系统的主要限制养分。水质受到流域发展的强烈影响，即洪水森林丧失、气候变化、人口增长和水位变化。水质成分的季节性变化是由降水和水文驱动的，特别是湄公河独特的季节性洪水脉冲。