| 纳帕海湖滨草甸湿地土壤氮动态对水文周期变化的响应 |
| 摘要点击 2050 全文点击 1587 投稿时间：2008-09-01 修订日期：2008-11-29 |
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| 中文关键词 水文周期 草甸 全氮 水解氮 湿地 纳帕海 |
| 英文关键词 Hydro-periods meadow total nitrogen hydrolysable nitrogen wetland Napahai |
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| 中文摘要 |
| 对滇西北高原纳帕海国际重要湿地湖滨草甸土壤氮动态进行了为期2 a的定位监测，分析了水文周期对草甸土壤氮转化过程的驱动规律.结果表明，湖滨草甸湿地表现出以土壤干湿交替为主的水文周期变化特征.水文周期对0～20 cm表层土壤全氮赋存有显著影响，表层土壤全氮含量变幅为0.96～1.30 g/kg，呈不规则“W”型变化模式，在雨季表层土壤全氮与水位波动趋势一致.旱季地下水位较低时，草甸土壤有机氮矿化作用强烈，土壤水解氮含量相对较高.在雨季草甸土壤水解氮含量与水位波动趋势相反，8月湖水退落土壤水解氮含量最高，0～20 cm和20～40 cm土层分别为222.19 mg/kg和47.41 mg/kg，湖水再次上涨土壤中水解氮含量下降幅度分别为42%和48%，表明雨季后期水位波动加速了土壤水解氮向湿地水体中的运移速率，增加了湿地水体氮营养负荷. |
| 英文摘要 |
| A two-year field located monitoring was carried out to study the impacts of hydro-periods on the lakeshore meadow wetland soil total nitrogen (TN) and hydrolysable nitrogen (HN) in Napahai plateau wetland in northwestern Yunnan province. The results show that meadow soil alternate drying-wetting is the significant characteristic influenced by hydro-periods. Hydro-periods of meadow wetland control the physical environment of meadow soil, and the occurrence of TN in the upper layer (0-20 cm) was influenced more significantly than in the deeper layer (20-40 cm) by wetland hydro-periods. The dynamics of TN (0.96-1.30 g/kg) show a shape of anomalous “W” in the upper layer. And in the rainy season, the dynamics of TN was the same as the trend of water level fluctuation, while the HN was in the reverse trend. The enzyme activities were influenced by hydro-periods and then controlled the mineralization process of organic nitrogen. In August when wetland water fell, the highest amount of HN was 222.19 mg/kg (0-20 cm layer) and 47.41 mg/kg (20-40 cm layer) respectively. But when the wetland water level rose, the HN was moved to wetland water by the rising water level, and the decrease amplitude was 42% and 48% respectively. Therefore the deterioration of the environment of water was aggravated. |
