The change of plant diversity during natural recovery process of vegetation in Ziwuling area A Preliminary Study of Herbaceous Vegetation Succession on the Abandoned Farmland at Water Catchment Region of Central Route for South-to-North Water Diversion Project Eco-restoration of abandoned farmland in the Loess Plateau Study on Species Diversity during the Succession of Plant Communities on Abandoned Farmlands in Guancen Mountains,Shanxi Effects of human disturbance on species diversity and niche of herbaceous plants along Qiyijiang riparian zone in Ya‘an City, Sichuan Province