The wind field and precipitable water vapor over the Tibetan Plateau are analyzed using the numerical model WRF. The spatial and vertical distributions of the relevant meteorological factors are summarized, providing evidence for selecting and further evaluating an astronomical site. This study serves as a further demonstration towards astro-climate regionalization, and provides us with an essential database for an astronomical site survey over the Tibetan Plateau.

Genetic structure of 22 populations of two self-pollinating pasture species, Elymus nutans and E. burchan-buddae collected from various altitudes of the Qinghai-Tibetan Plateau was studied using fluorescence-based amplified fragment length polymorphism technique. Analysis of molecular variance revealed 42.97% and 37.63% among-population variation for the two Elymus species, respectively, indicating that the majority of the total variation presented within populations. This result contradicts the common genetic variation pattern for a selfing plant species: lower generic variation within populations. STRUCTURE analyses of the Elymus populations indicated an evident admixture genetic structure, particularly among neighboring populations from the same region, supporting the hypothesis of considerable seed dispersal among populations. The among-population gene flow promulgated by grazing animals may promote the maintenance of genetic diversity in the pasture species, particularly in small and fragmented populations within a given region. The gene flow promulgated by grazing animals may promote the maintenance of genetic diversity in the pasture species, particularly in small and fragmented populations within a given region.

Dynamics of aboveground and underground biomass of Qinghai flat-stem bluegrass (Poa pratensis vayr. anceps Gaud. Cv in "＞" shape, and vertical distributions of biomass of roots, rhizomes and underground were all in "T" shape and fit equation of Y= l-βD. There was direct correlation between biomass of above ground and biomass of underground. Ration of underground to aboveground was 0.4l.