【摘要】 为研究何种生态退耕对黄土丘陵地区植被恢复较好,以典型黄土丘陵沟壑区大南沟小流域为研究区,采用传统植物群落调查法从退耕方式和退耕年限两个方面探讨生态退耕对草本层植物多样性的影响。结果表明:(1)在生态退耕30a内,随着退耕年限的增加,草本层植物丰富度指数、两多样性指数(Simpson指数和Shannon-Wiener指数)和均匀度指数都呈现增加的趋势。但前期增加不显著,后期增加显著。(2)不同生态退耕方式对草本层植物多样性的影响差异显著。三种多样性指数均表现为退耕还草>退耕还林>退耕还灌,且丰富度指数退耕还草(23.875)较退耕还林(14.606)和还灌(14.556)显著增加;Simpson多样性指数和Shannon-Wiener多样性指数退耕还草(0.945,3.048)和退耕还林(0.931,2.992)较还灌(0.912,2.563)显著增加。退耕还草优于退耕还灌和退耕还林,对草本层植物群落多样性影响最小,是最佳生态退耕方式。更多还原

【Abstract】 In order to study which measure of ecological restoration is better for vegetation restoration in the hilly and gully area of Loess Plateau,the Danangou Catchment was selected as study area.Based on traditional vegetation investigation,the effects of ecological restoration on species diversity of herb plant community were discussed on aspect of measures and time of land use conversion.The results showed that:(1)within 30years after the farmland abandonment,the richness index,the Simpson index,the ShannonWiener index and the evenness index increased over the time.Furthermore,the indices increased slowly in early period but increased at a high rate in later period;(2)the measures of ecological restoration had significant influence on the diversity of species in herb community,on the aspect of richness index,the value in abandoned farmland(converted from traditional farmland 23.875)is significantly higher than that in forestland(14.606)and shrubland(14.556).The Simpson index and the Shannon-Wiener index in abandoned farmland(0.945,3.048)and forestland(0.931,2.992)were significantly higher than that in shrubland(0.912,2.563).Compared with shrubland and forestland(all converted from traditional farmland),abandoned farmland has more positive effects on the species diversity of herb community.更多还原