Study On Ecological Characteristics And Soil Carbon Of Typical Artificial Shrub Communities In Gonghe Basin

Gonghe Basin is located in the northeast of Qinghai-Tibet Plateau. Land degradation and desertification worsened because of frequent wind erosion, poor conditions and the impact of human activities. In recent years, vegetation restoration and reconstruction are widely carried out, windbreak and sand fixation and soil and water conservation are achieved good control effect. After more than 50 years of experiments, Sand Control Experimental Station of Qinghai Province have achieved good results, planting Caragana korshinskii and Artemisia ordosica on the dunes, planting Salix cheilophila, Salix psamnophila in the lowland, gradually evolved into semi-fixed dunes and fixed dunes. Vegetation and soil has been improved in varying degrees. Sha Zhuyu foresty was selected as the study areas, to investigate the vegetation and soil. This study can provide a reference for alpine vegetation restoration in sandy land.There were four kinds of typical shrub plantations in alpine study land vegetation recovery areas of Gonghe Basin: Caragana korshinskii, Hippophae rhamnoides, Salix psammophila and Salix cheilophila. To reveal the differences in species diversity of understory vegetation and environmental factors, four kinds of artificial shrubberies with similar forest age were selected in the Gonghe Basin, Qinghai Province. Species diversity and relevant environmental factors of community and herbaceous was investigated under forest. The results showed that:(1) There were significant impacts of plantation types on species diversity. Species diversity index and species richness index of herbaceous under forest of each plantation type had a similar pattern, changing as Hippophae rhamnoides > Caragana intermedia > Salix psammophila > Salix cheilophila, while dominance index had a contrary patten.(2) Soil particle size composition of topsoil at different plantation varied significantly, but fine sand ocupied a larger proportion. Carbon sequestration of Caragana korshinskii, Hippophae rhamnoides, Salix psammophila and Salix cheilophila were significantly different.(3) Soil are alkaline in four communities. The impacts of community types on soil nutrition content were obvious. Soil organic carbon carbon storage(0~100cm) of different community types were: Hippophae rhamnoides, the largest content, 9.42kg/m2, Salix psammophila, 6.73kg/m2, Salix cheilophila, 6.06kg/m2, Grassland, 4.56kg/m2, Caragana Korshinskii, the smallest content, 3.67kg/m2.(4) Both Soil texture and stratified conditions were different under different community types. Soil organic carbon density decreased with soil depth increasing, which was largest in surface(0~10cm). Compared with the grass land, the bottom slope soil organic carbon content increased.(5) Sha Zhuyu Woodland covers an area of 848.49hm2 and total soil carbon sequestration is 42.18×103t. Carbon sequestration of Caragana korshinskii is 15.47×103t, Hippophae rhamnoides is 4.62×103t, Grassland is 2.85×103t, Salix psammophila is 1.14×103t, Salix cheilophila is 8.32×103t, sandy land is 2.25×103t, other land use patterns is 7.53×103t.