Research on the Vegetation and Soil Traits of Improved and Unimproved Grasslands in Karst Region

PurposeTo explore the effect and suitable method of natural grasslands improved by Pennisetum clandestinum in karst rocky area of southern China.

MethodWe selected improved grassland by P. clandestinum and unimproved natural grassland, and quantitatively analyzed the important values of plant species, species diversity, biomass composition, nutrients in herbage and soil and community stability of two kinds of grasslands.

ResultThe plant species richness index, Shannon-Wiener index, Simpson index and Pielou evenness index were improved grasslands<natural grasslands; the biomass of living matter, shoot/root, and the proportions of gramineae and leguminous biomass were improved grasslands>natural grasslands, but the biomass proportions of native grasses and the other plants were improved grasslands<natural grasslands; the nitrogen and phosphorus contents in herbages were improved grasslands>natural grasslands, but the neutral detergent fiber, acid detergent fiber, cellulose, acid detergent lignin, acid-insoluble ash contents in herbages and the soil organic matter were improved grasslands<natural grasslands; the distribution of Raunkiaer frequency coefficient of plant species in the improved grasslands showed a typical "anti-J" shape, and the community tended a relatively stable stage.

ConclusionP. clandestinum had a good effect in the natural grassland, which will provide a suitable method for natural grassland improving in karst rocky area of southern China.