近10年来三峡消落带土壤氮、磷时空分布特征研究

消落带是位于水陆交错带的一种特殊生态系统.消落带土壤作为生态系统中氮、磷元素重要的“源”与“汇”，在生物地球化学循环研究中具有重要意义.该研究基于中国知网CNKI以及Web of Science数据库检索近10年三峡消落带土壤氮、磷研究文献，提取w（TN）、w（TP）数据并进行统计，从宏观尺度上分析w（TN）、w（TP）的时空分布特征.结果表明:①高程分布上，当高程高于155 m时，土壤w（TN）（0.75~1.17 g/kg）随着高程增加呈下降趋势，土壤w（TP）未发生显著变化（0.53~0.60 g/kg）；当高程低于155 m时，土壤w（TN）处于较低水平（0.66~0.86 g/kg），但w（TP）维持较高水平（0.60~0.76 g/kg）.②时间分布上，消落带土壤w（TN）整体呈现逐年递减的趋势，Pearson相关系数为-0.64，但是w（TP）没有显著变化.③地区分布上，三峡上游库区消落带土壤w（TP）出现显著高值，下游库区w（TN）出现显著高值.研究显示:不同高程土壤受植物残体分解等因素影响，在落干期w（TN）上升，在浸没期向上覆水体释放TN；水位调节导致的淹没强度变化对消落带土壤中TN产生淋溶作用，而对TP的影响较小；对于消落带上游地区应更关注土壤中高w（TP）带来的环境风险，而对于消落带下游地区应更关注因水土流失和非点源输出导致的高w（TN）所致环境风险. 

Spatial and Temporal Distribution Characteristics of Soil Nitrogen and Phosphorus in Three Gorges Water Level Fluctuation Zone in Last Decade

The water level fluctuation zone is a special ecosystem located in the interlaced zone of water and land. As an important 'source' and 'sink' of nitrogen and phosphorus in the ecosystem, the soil in the water level fluctuation zone is of great significance in the study of biogeochemical cycles. Database of CNKI and Web of Science were used to search the relevant references on soil nitrogen and phosphorus in the Three Gorges water level fluctuation zone in the past 10 years. The research extracts w(TN) and w(TP) data from it, and analyzes the temporal and spatial distribution characteristics of w(TN) and w(TP) on a macro scale. The results show that: (1) In terms of elevation distribution, when the elevation is higher than 155 m, the soil w(TN) (0.75-1.17 g/kg) shows a downward trend as the elevation increases, and the soil w(TP) does not change significantly (0.53-0.60 g/kg). When the elevation is lower than 155 m, the soil w(TN) is at a low level (0.66-0.86 g/kg), but the w(TP) maintains a high level (0.60-0.76 g/kg). (2) In terms of temporal distribution, the soil w(TN) of the water level fluctuation zone showed a decreasing trend year by year. The Pearson correlation coefficient was -0.64, but w(TP) did not change significantly. (3) In terms of spatial distribution, the soil w(TP) in the water level fluctuation zone of the upper reaches of the Three Gorges Reservoir has a significant high value, and the lower reaches of the reservoir area has a significant high value of w(TN). The research shows that the w(TN) of the water level fluctuation zone soil increase during the dry period and can leach to the overlying water body during the immersion period due to the decomposition of plant residues; The change of submergence intensity caused by the adjustment of water level has a leaching effect on TN, but has little effect on TP; Attention should be paid to the environmental risks caused by high w(TP) in the soil of the upstream area, as well as environmental risks caused by soil erosion and non-point source output with high w(TN) in the downstream area.