Species Diversities of Plant Communities of Degraded Artificial Grassland,“Heitutan”and Natural Grassland in the“Three-River Headwaters”Region

In order to further study the effect of artificial grassland on restoring theheitutan,the species compositions of plant communities in degraded artificial grassland,heitutanand natural grassland were analyzed.The results showed that the average species number of degraded artificial grassland,heitutanand natural grassland was 29,32 and 35,respectively.The important value of gramineae accounted for21% of total community in the degraded artificial grassland,the important value of forbs accounted for88.2% of total community in theheitutan.The important value of gramineae and cyperaceae accounted for 37.4% of total community in the natural grassland.Shannon-Wiener indexes,Simpson dominant concentration indexes and Pielou evenness indexes of different grasslands were all ordered as natural grasslandheitutandegraded artificial grassland.Sorensen and Jaccard indexes showed that degraded artificial grassland andheitutanhad the biggest community similarity,followed byheitutanand natural grassland,degraded artificial grassland and natural grassland had the smallest community similarity.The percentage of forbs in degraded artificial grassland was about 10%less than heitutan.The conclusion was that artificial grassland was degraded after several years,but the artificial grassland promoted the restoration of degraded plant community inheitutanto a certain extent.