Effects Of Tunnel Space Of Plateau Zokor On Vegetation Characters Of Alpine Meadow

The plateau Zokor(Myospalax baileyi) is one of the rodents in the alpine meadow ecosystem,which it lives in the underground all its life and forms a number of the enormous tunnels by excavating the soils,and it pushes out the superfluous soils to the surface;It lives on the mixed grasses and restrains their growth with grazing.Because of its excavating and grazing,it has affect on the vegetation succession of the degenerative alpine meadow.In order to probe into the relationship and mechanism between the plateau Zokor,tunnel space and the vegetation characters on the tunnels,the research was conducted in a typical distribution site of the plateau Zokors in Maqu county from 2006 to 2008,studying tunnel space and rat group density,the basic characteristics of vegetation.The main results were as follows:1.Tunnel space and rat group density was negative correlation(P＜0.05).Tunnel space(35%-45%) was not only a rat group critical density range of take-off and langing,but also a relatively stable interval of population density.This was explained in part that food richness was an important reason that determined the plateau Zokor to migrate.2.The moderate tunnel space(35%-45%) had not a significant affect on vegetation cover(P＞0.05),but had a significant affect on species diversity,height and aboveground biomass.And then it could increase the dominance of grasses and weaken the dominance of the toxic grass and root type of cyperacene.3.The vegetation on the tunnel,in addition to species diversity and cover no significant difference(P＞0.05),was significantly lower than control(P＜0.05),but height and aboveground biomass were significantl y higher than control(P＜0.05).4.The grasses and weeds on the tunnel in the dominant position in the community were significantly higher than the control group,but the toxic grasses and sedges were significantly lower than control.The noted that under certain conditions the Zokor activities could promote the dominant position of the grasses in the communities.The toxic grasses were the contrary;When the activities were too time-intensive,the sedges competitiveness would be significantly curb.However, the weeds were not affected.5.To a large extent,the plateau Zokor had the nature of construction and repair for the vegetation.And it was an integral part of natural vegetation dynamic process. Even if the economic benefits from human point of view,this impact was also of positive significance.