岷江上游大沟流域自然封育灌丛群落特征

在岷江上游大沟流域,以受干扰而退化,经封育后自然恢复至灌丛阶段的植物群落为研究对象,分析了自然恢复灌丛群落的种类组成、区系特征、结构及物种多样性特征.结果表明:在1 hm2的灌丛群落样地中,共调查到木本和草本植物43科,88个属,135种,其中:草本21科44属49种、木本34科47属86种.木本物种数和个体密度都随着基径级、高度级而递减;不同高度级和不同基径级的个体密度呈显著的正相关关系.恢复后的灌丛具有较高的物种多样性.岷江上游自然恢复灌丛阶段的植物群落其外貌虽然呈现灌丛状,但其组成成分却相当丰富,其中本研究区域的顶级乔木树种如辽东栎等已在群落中出现并占有较大的优势.对于该区的退化群落而言,封育为一种有效的植被恢复和物种多样性保育方式.

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.