Abstract: The Yukeng forest community,situated in Xianju County of Zhejiang Province,is rich in plant class whose family and genus are of scattered composition.There are a bit more genus in the tropical zone than in the temperate zone in terms of the distribution type of genus.Based on Raunkiaer's life-form statistics,the life-form phaenerophyte class of the community ranks the first in number and the hemicryptophyte the second. The leaves of the community are mainly microphyll,simple, herbaceous and unentire whereas they are mostly microphyll,simple,coriaceous and unentire in the tree layer. The community's vertical structures can be divided into tree layer, shrub layer,herb layer and ground layer. In this paper,the overall relatedness of the tree layer's 40 main species and the association between paired species of the forest community were examined by using the methods of variance ratio(VA) and χ² test by 2×2 contingency table.Its result shows that the major interspecies of the tree layer,on the whole,have the great positive relatedness,and that there are more paired species of positive association than those of negative ones.

Key words: evapotranspiration, eddy covariance method, alpine shrubland meadow, Qinghai-Tibet Plateau, seasonal variation, interannual dynamics, ChinaFLUX.