宁夏盐池县草地沙化对植被与土壤特征的影响

通过野外调查和室内分析相结合的方法,研究了盐池县不同沙化程度下草地植被特征和土壤特性的变化,以探讨植被和土壤对沙化的响应机制。结果表明,随着草地沙化程度的加剧,植被组成发生变化,多年生草本植物呈逐渐减少,一年生草本植物呈逐渐增加的趋势;生物多样性指数变化趋势为轻度沙化草地到中度沙化草地增加,自中度沙化草地至极度沙化草地先降低后又增加,中度沙化阶段是草地植物群落特征变化的重要转折时期。随着草地沙化加剧,土壤含水量、有机质、氮含量降低;重度沙化阶段土壤磷、钾含量最高,pH值和可溶性盐无明显变化规律。

Impact of Grassland Desertification on Vegetation and Soil Properties in Yanchi County of Ningxia Hui Autonomous Region

In combination of field investigation with laboratory analysis, changes of plant community and soil characteristics were studied under different degrees of desertification in Yanchi desertification grassland to investigate the responses of vegetation and soil to desertification. Vegetation composition changes with the increased degree of grassland desertification. Perennial species gradually gave place to psammophyte annuals. Diversity index increased from mild desertification to moderate desertification grasslands. From moderate to extreme desertification grasslands, diversity index first decreased and then increased, which shows that the stage of moderate desertification is an important turning point for changes in plant community characteristics. Soil water content, organic matter and nitrogen content were reduced with increased sandy desertification on grassland; available P and available K content were the highest in extreme desertification stage, and changes of pH value and salt content did not show an obvious trend.