中国云南高原抚仙湖和星云湖水系氮和磷的分布状况和动态变化

2000年11月和2001年6月，通过深入细致的实地调查和分析所收集的样本，对抚仙湖和星云湖水系氮和磷的分布状况与动态变化进行了研究。星云湖的氮磷总量处在一个高浓度状态，并伴随着蓝藻水华的大爆发，而抚仙湖的氮磷总量浓度是星云湖的二十分之一到四十分之一。在雨季，抚仙湖的溶解磷和磷总量随着深度而增加，这暗示着下层滞水带对有机磷微粒活跃的降解作用以及由雨季地表径流增加而带来的大量的土壤矿石的沉积。在已测量和已发表资料的基础上，检查对星云湖和抚仙湖氮磷总量的预测。星云湖大部分外来的磷和氮从一个出口流出，但是估计进入抚仙湖97％的磷和25％的氮被埋藏在沉积物里。反硝化作用可能是抚仙湖中余留总氮耗损的原因。减少来自汇流区的总氮和总磷负荷是保护星云湖和抚仙湖所必不可少的。

DISTRIBUTION AND DYNAMICS OF NITROGEN AND PHOSPHORUS IN THE FUXIAN AND XINGYUN LAKE SYSTEM IN THE YUNNAN PLATEAU, CHINA

Distribution and dynamics of nitrogen and phosphorus in the Fuxian and Xingyun Lake system were studied in November 2000 and June 2001 by intensive field surveys and analysis of the collected samples. Total nitrogen (TN) and total phosphorus (TP) were present in high concentrations in Xingyun Lake with a heavy development of cyanobacterial blooms, while their concentrations in Fuxian Lake were one-twentyth to one-fortyth of those in Xingyun Lake. Increase of dissolved late and total phosphorus with depth in Fuxian Lake in rainy season suggested active hypolimnetic degradation of organic particulate phosphorus and considerable external supply of soil minerals by increased runoff from land by rain and their subsequent sedimentation in the lake. Based on the measured and published information, the budget of TP and TN in Xingyun Lake and Fuxian Lake was examined. Although in Xingyun Lake a large percentage of external inputs was discharged out from a outlet, in Fuxian Lake 97% of TP input and 25% of TN input were evaluated to be buried in the sediments. Denitrification was assumed to be accountable for remained TN loss in Fuxian Lake. Reduction of external loading of TN and TP from the watershed was concluded to be essential for the sustainable conservation of both Xingyun Lake and Fuxian Lake.