Community Character istics of Shrub Vegetation by Forest Closing inDagou Catchment, Upper Reaches of Minjiang River

In order to understand the effect of closed forest, the species composition, flora characteristics, height classstructure, diameter class structure and species diversitywere analyzed in a 1 hm2 p lot in natural recovery shrub stage offorest vegetation in Dagou catchement, upper reaches ofMinjiang River. There was a floristic composition with 43 families, 88 genera, and 135 species in the p lot, in which, there were 49 species of 44 genera of 21 families of herbs and86 species of 47 genera of 34 families of woody p lants ( trees and shrubs combined). The areal-types of families andgenera were abundant, but the areal-types of families dominated by North Temperate and Cosmpolitan component,which accounted for 34. 9%, respectively. The areal-types of genera were dominated by temperate genera, accountingfor 72. 8%, in which north temperate genera was 39. 8%. Both the species number and individual density decreasedwith the increasing of height class and basal diameter. There was a significant positive correlation between species abundance and individual density for different height class and different basal diameter in the community. Although thephysiognomy of the communitywas shrubby, the componentwas rich. The tree species in climax community of the region ( such asQuercus liaotungensis) was p resent and somewhat dominant in the community. Closed forestwas an effective method to restore the degraded community caused by human disturbance in the valley.