不同封育管理对沙质草地土壤与植被特征的影响

Effects of different exclosure management on soil and plant characteristics of sandy grassland

针对退化沙质草地土壤和植被的恢复问题,选取封育19年(人工抚育19年)、封育19年(人工抚育5年)和封育10年(自然恢复)沙质草地为研究对象,同时选取流动沙地作为对照,结合野外调查及室内化学分析方法,进行了不同封育管理沙质草地土壤理化性质和植被特征的比较研究。结果表明,1)与流动沙地相比,封育19年沙质草地(人工抚育19年)植被高度、密度、冠幅、盖度、生物量及土壤养分含量显著增加,0～20cm层土壤容重、0.05～2mm的砂粒含量显著降低,退化沙质草地在恢复过程中植被与土壤之间逐渐形成一个相互作用、相互影响的系统。2)封育沙地植被特征和土壤理化性质受坡位影响比流动沙地显著(P<0.05),封育沙质草地中SOC、氮磷钾全量和速效养分含量沿上坡到下坡呈增加趋势。3)天然封育+人工抚育措施对沙质草地的影响和改善程度高于纯天然封育措施,它是促进我国北方退化沙质草地恢复的适宜方法。

To discuss the restoration of soil and plant of degraded sandy grassland,19-year-old exclosure（19-year-old artificial restoration）,19-year-old exclosure（5-year-old artificial restoration）,10-year-old exclosure（natural restoration） sandy grassland were chosen to be the study subjects.Combining field survey with laboratory experiments,the influence of different exclosure management on soil physicochemical properties and plant characteristics of sandy grassland were researched taking,the mobile sand as the control.1） Compared with the mobile sand,the plant height,density,crown diameter,coverage,biomass and soil nutrient of 19-year-old exclosure（19-year-old artificial restoration） sandy grassland increased,while soil bulk density,sand（0.05-2 mm） content of the surface layer（0-20 cm） decreased.The plants and soil gradually formed an interaction system with restoration of degraded sandy grassland.2） The effects of slope on soil physicochemical properties and plant characteristics of exclosure were more significant than mobile sand（P〈0.05）.In the enclosed lands,SOC,TN,TP,and TK,available N,available P and available K increased from upper slope to foot slope.3） The exclosure sandy grassland（artificial restoration） had better improvement on soil physicochemical properties and plant characteristics compared to sandy grassland restored by only natural force.It is an appropriate method for recovery of degraded sandy grassland in northern China.