宁夏荒漠草原自然恢复演替过程中生态效应的评价

目的]评价宁夏荒漠草原自然恢复演替过程中生态效应。方法]对封育3、4、5、6、7年及未封育荒漠草原植被和土壤进行调查、分析,并选取土壤容重、有机质、全氮、水解氮、速效磷、速效钾、植物群落密度、高度、盖度、生物量及多年生草本植物比例为评价指标,采用主成分分析法对不同封育年限草地的生态效应进行综合评价。结果]群落密度、盖度以封育5年的草地最高;土壤有机质、全氮含量无明显变化规律;土壤速效氮、速效钾含量以封育4年的草地最高,土壤速效磷含量以封育6年的草地最高。结论]草地生态效应综合得分以封育5年的草地最高,此时可考虑封育草地的适度利用。

Evaluation on Ecological Effects during Natural Restoration for Desert Steppe in Ningxia

Objective] The research aimed to evaluation the ecological effects during natural restoration for desert steppe in Ningxia.Method]The vegetation and soil for desert steppes which are unenclosed and enclosed for 3 years,4 years,5 years,6 years and 7 years were investigated and determined.The soil bulk,organic matter,total nitrogen,available nitrogen,available phosphorus,available kalium,plant density,height,coverage,biomass and herbaceous perennial plant proportion were chosen as evaluation indices.The principal component analysis was used to evaluate the ecological effects.Result]The results showed that the plant density and coverage were the highest in the 5th year.Soil organic matter and total nitrogen content showed no significant variation.Available nitrogen and available kalium contents were up to the highest in the 4th year;Available phosphorus content was highest in the 6th year.Conclusion]The synthetical score of ecological effect in the 5th year was the highest.The grasslands can be properly used at this time.