Isolation and purification of polysaccharide RPPSIIa from Rabdosia rubescens and its activity Isolation and purification of polysaccharide RPPSIIa from Rabdosia rubescens and its activity Effect of land-use type on enzyme activity in black soil Ground vegetation as indicators of topsoil chemical properties in Dongguan, South China Topographic Correlates of Understory Plant Species Distribution in Nanling National Nature Reserve,Guangdong Community structure in relation to microtopography in a montane evergreen broadleaved forest in Chebaling National Nature Reserve Effects of PEG Stress on the Drought Resistance of Six Turfgrass Varieties of Lolium perenne L. Vegetation variations under different exclusion measures and their correlation to soil factors