Study On Spatial Distribution Of Soil Phosphorus Of Alpine Area In Eastern Qinghai-Tibetan Plateau

The soil phosphorus is one of important carriers in materials circulation of grassland ecosystem, it has the influential role to the grassland plant growth and the raising livestock production. Understanding that under each environment like climate, the terrain, the vegetation condition, the spatial variation rule of soil phosphorus is a important link to understand the structure and function of region ecosystem, is also a influence key to appraise the ecosystem-type change to the soil phosphorus. Alpine area in eastern Qinghai-Tibetan Plateau is quite sensitive to global climatic changes. Under the background that alpine meadow degrade extremely and swamp shrank badly, how soil phosphorus spatial distribution in different alpine vegetation cover will become the focus of the research. Analyzing the spatial heterogeneity of soil total P of Alpine area in Eastern Qinghai-Tibetan Plateau from different plot scales occupying Kriging and geo-statistical methods. Besides, the vertical distribution characteristics of soil total P are studied with field investigation and laboratorial analysis. In this paper, the results are:as the plot scale increases, the spatial heterogeneity of soil total P in alpine shrub becomes more and more obvious, and that of the soil total P in alpine meadow increases then slightly reduces. Compared with the alpine shrub, the spatial heterogeneity of soil total P in alpine meadow is found to be higher, sampling in alpine shrub is more random. The main cause of sampling error in alpine shrub is the plant cover change and spatial partitioning of soil total P, but the causes of sampling errors in alpine meadow is micro-terrain and transplant of phosphorus along the slope. In three typical alpine Upland Shrub Meadow, Upland Meadow and Terrace Meadow we choose, the content of total P in Upland Shrub Meadow first increases and then reduces along the soil profiles, its maximum is 0.139%, appeares in 10-20cm. But Upland Meadow and Terrace Meadow soil total P all have a descending trend with the deepening of soil layer, while their content in depth of 0-10cm are higher than other layers. At 10-20cm and 50-60cm soil layers, total P in three plots are significantly different, other layers are no significant level. The distribution of total P in soil profiles is comparatively homogeneous. There is significant or highly significant correlation between total P and organic matter, total nitrogen, bulk density, water content, surface area as well as pH. Because of variation of vegetation and degradation, the spatial distribution difference of total P happens mainly within 0-30cm soil layers range, below 30cm its space difference diminishes.This shows that, small scales spatial heterogeneity and control process of soil total P in different plant covers provide scientific foundation to control ecological factors effectively in alpine area of Eastern Qinghai-Tibetan Plateau.