宁夏南华山草地造林对土壤质量的影响OA

To investigate the ecological benefits of afforestation in mountainous grasslands and to clarify the impact of afforestation age on soil quality,this study examined the physicochemical properties and enzyme activities of the 0～40 cm soil layer in Qinghai spruce(Picea crassifolia)plantations of varying ages(10,20,and 30 years)and natural grassland within the Nanhua Mountain National Nature Reserve,Ningxia,China.It employed a minimum data set(MDS)and a soil quality index(SQI)to conduct a comprehensive evaluation of soil quality across different plantation ages.The results show that the overall soil quality in afforested areas is superior to that of natural grasslands and improves significantly with longer afforestation periods.Notably,soil pH,ammonia nitrogen content,alkaline phosphatase,alkaline protease,hydrogen peroxide,β-1,4-glucosinase,and sucras activities were higher in afforested areas compared to natural grasslands.Specifically,the 20-year afforestation site exhibited the highest total nitrogen and soil moisture content,while the 10-year site recorded the highest nitrate nitrogen content.Conversely,urease activity was significantly greater in natural grasslands than in all afforested sites.This study provides scientific evidence supporting the ecological benefits of grassland afforestation in mountainous regions,demonstrating that afforestation can effectively enhance soil quality and facilitate the recovery and improvement of ecosystem functions.