三峡库区消落带不同高程柳树林地养分特征

Spatial Characteristics of the Soil Nutrients in Willow Forest Land at Different Elevations of the Three Gorges Reservoir Area,China

在三峡库区消落带设置固定监测样地,研究消落带不同水位高程土壤氮磷钾含量、pH值、微生物生物量碳含量和有机质含量的变化特征.结果表明：受三峡库区不同水位影响,消落带172水位高程到173,174水位高程,土壤养分评价得分降低,土层的速效氮含量下降27.53%～50.33%,速效钾含量下降21.53%～23.25%,速效磷含量增加169.00%～436.68%,土壤有机质含量下降20.44%～58.16%,全磷含量基增加38.98%～45.05%,全钾含量下降4.89%～9.65%,微生物量碳降低37.09%～77.45%,pH值降低6.97%～8.07%.相关分析发现,水位高程与有机质含量、速效氮含量、速效磷含量、微生物碳含量极显著相关（p〈0.01）,与pH、全磷、全钾显著相关（p〈0.05）.

Monitoring transects were set in the hydro-fluctuation belt of the Three Gorges Reservoir with an elevation of 172-174 mto investigate the changes in the contents of N,P,K,pH,microbial biomass C and organic matter of the soil,which experienced the influence of different water levels.The results showed that influenced by water level fluctuation,the contents of soil N,P,K,pH and organic matter changed at different altitudes in the hydro-fluctuation belt.The evaluation scores of soil nutrients were reduced.Available N decreased by 27.53%～50.33%,available K decreased by 21.53%-23.25%,available P increased by 169.00%～436.68%,content of soil organic matter decreased by 20.44%～58.16%,total P increased by 38.98%～45.05%,total K decreased by 4.89%～9.65%,content of microbial biomass C decreased by 37.09%～77.45%,and pH decreased by 6.97%～8.07%.Water level elevation was in a highly significant correlation with the contents of organic matter,available N,available P and microbial biomass C（p〈0.01）and in a significant correlation with the contents of total P,total K and pH（p〈0.05）.