The Effects Of Soil Nutrients,Soil Microbes And Vegetation Of Alpine Grassland Under Different Management Regimes In Yushu District Of Qinghai Province,China

Compared the soil nutrients in different depth of soil layer,microbes components and grassland vegetation structure of alpine grassland under three management regimes including natural grassland,natural grassland under mice control and enclosed natural grassland under mice control in Yushu district of Qinghai province were studied between 2012 and 2013,to discuss the effects of the different management regimes on the improvement of degraded grassland the in Yushu.The main results are as following:1.For the same management regime,the changing potential of soil nutrients was as follows: with the increase of soil depth,total nitrogen content showed a downward trend;total phosphorus content was focused on the top layer of soil;in 0 ~ 5 cm depth of soil layer,the content of total potassium was the least on the three grasslands;available nitrogen,available phosphorus and available potassium were mainly focused on the top layer of soil under the different management regimes.2.The change of soil nutrient content in the same soil layer and under different grassland management regimes was showed as follow: in 2012,the content of soil total nitrogen,total phosphorus,available nitrogen in 0 ~ 5 cm soil layer and available potassium in 15 ~ 20 cm soil layer on the grassland under the management of mice control and mice control together with enclosure were significantly higher than those of natural grassland without any treatment;the content of available phosphorus on the grassland under the mice control together with enclosure was the highest in 15 ~ 20 cm soil layer.In 2013 the content of soil total nitrogen on the natural grassland without any management was significantly higher than that of management with mice control and mice control together with enclosure;the content of total phosphorus on the grassland under the management of mice control was highest;in each soil layer the contents of total potassium on the grassland under the mice control together with enclosure was significantly higher than those of natural grassland without any management;the content of available nitrogen on the grassland under the management of mice control was the highest among all the soil layers except for 0 ~ 5cm layer;the content of available phosphorus on the natural grassland without any treatment was the highest;the content of available potassium on the grassland under thetreatment of mice control was the highest in 5 ~ 10 cm soil layer.3.For the same management regime,soil microbe communities of each type under different soil layers were focused on the top layer of 0 ~ 5 cm,with the increasing of soil depth,the numbers of all kind of microbes tested showed a downward potential.As far as the same soil layer was concerned,the number of soil bacteria,soil fungus,soil actinomyete,and soil nitrogen bacteria groups were increased to certain extent under the regimes of natural grassland under mice control and enclosed natural grassland under mice control compared to the natural grassland without any management.The content of soil microbe biomass C,N and P on the grassland under the mice control and mice control together with enclosure were significantly higher than that of natural grassland without any management.The potential of the total number of soil microbe in each types of alpine grassland management regimes were bacteria higher than that of actinomyete,and the number of fungus was the least.4.The effects of different managements regimes on grassland functional groups were significantly different,natural grassland under mice control and enclosed natural grassland under mice control management regimes have an effect for growth and seedling recruitment promotion in Gramineae,Cyperaceae comparision to the natural grassland without any treatment.The species diversity,evenness and richness index were significantly increased under the management with natural grassland under mice control and enclosed natural grassland under mice control compared to that of no treatment applied on.The research results suggested that natural alpine grassland under mice control and mice control together with enclosure facilitated the increase of the content of soil nutrient,the action of microbe,and the natural regeneration of grassland,and meanwhile benefit to protection of the species diversity in the pastoral area,especially in the Qinghai and Tibetan Plateau areas.