Spatial Distribution Characteristics Of Soil Nutrients In Two Species Of Hippophae Rhamnoides L.shrubs On The Eastern Of Qinghai-Tibetan Plateau

Qinghai-Tibet Plateau is a sensitive area of global change.Alpine meadow is one of the most important grassland resources for grazing.With the global climate change,the quality of grassland soil,have different degree degrade,and Hippophae rhamnoides L.patches appeared gradually on some grassland.The nutrient dynamics of Hippophae rhamnoides L.shrub soil also partly reflect global changes on the eastern edge of Qinghai-Tibet Plateau.Our research choice in different elevations(each equipped with 0-5cm,5-10 cm,10-20 cm at an elevation of three soil depths)the Hippophae rhamnoides ssp.sinensis shrub.and H.thibetana Schlechtend.shrub soil as the research object,combined with field investigation and laboratory analysis,spatial distribution of the main soil nutrients of alpine meadow scrubland in the eastern edge of Qinghai-Tibetan Plateau.The main results are as follows:1)Effects of elevation on soil characteristics of Hippophae rhamnoides ssp.sinensis and H.thibetana Schlechtend.,soil moisture increased significantly with the increase of altitudes,the soil bulk density first increased and then decreased with a hump pattern,and the soil gradually change to the weak acidic.It showed obvious difference,soil p H and bulk density of soil increased gradually along the soil depth.2)The contents of soil organic carbon,total nitrogen and total phosphorus and three of them reserves increased with elevation increased significantly for H.rhamnoides ssp.sisnensis and H.thibetana Schlecht.shrub.Because of soil bulk density decreasing,organic carbon,total nitrogen and total phosphorus storage reserves gradually increased from the soil surface to the bottom layer,and the two kind of soil total phosphorus reserves increase compared with the soil organic carbon and total nitrogen reserves are more significant.It said that the role of H.rhamnoides ssp.sinensis and H.thibetana Schlechtend.shrub in soil nutrient storage of soil C,N and P can not be ignored.3)Soil C/N decreased with elevation increasing of H.rhamnoides ssp.sinensis and H.thibetana Schlechtend shrub,and no significant changes among soil depth.The soil C/N China scrubland have a maximum of 17.78 at an altitude of 3000m surface;Both soil N/P and C/P increased with the elevation increasing and decreased significantly with the increase of soil depth of H.rhamnoides ssp.sinensis and H.thibetana Schlechtend.Shrub.The maximum value of N/P 8.29 in H.thibetana Schlechtend.shrub soil at an altitude of 3600 m surface,the maximum value of 88.79 C/P in H.rhamnoides ssp.sinensis shurb at an altitude of 3100 m surface.That indicated that the effect of elevation on soil nutrient characteristics of the influence is more important and more complex.4)Comparing soil characteristics come from the same elevations and similar habitats between H.rhamnoides ssp.sinensis and H.thibetana Schlechtend.shrub.It showed that soil all characteristics is superior from H.thibetana Schlechtend.than H.rhamnoides ssp.sisnensis shrub.In the future,H.thibetana Schlechtend.shrub should be chosen as the shrub of the degraded grassland restoration and soil nutrient fixation.