Abstract:

In order to protect the biodiversity, the restoration of the degraded vegetation is indispensable. According to the gradient of the altitude in the source region of Minjiang River, three transects of vegetation plots were settled to investigate the facts of the vegetation and the environment. Then two databases of the sites and species were established. Then the regression analysis between the ordination axes and environmental elements were applied. The results suggested that: On the first axis scores of DCA, the altitude was increasing gradually from up to down, the gradient pattern of altitude distribution of vegetation got to embody. In the middle of mountain body, there were many layers of vegetation structures, and the main arborous species were Abies faxoniana, Picea asperata and small mount of Betula platyphylla Suk. Using the DCA analysis to sort, the author analyzed the 73 quadrats and 316 plant species, calculating out the average values of the axis scores of DCA of each formation, combined with the result of DCA ordination in previous paper, namely, the ecological gradient relationship and physiological characteristics of vegetation and ecological adaptability which the axis scores of DCA showed, we got the succession relationship of vegetation formation of the source region of Minjiang River: Ass. Abies, Picea-Ass. Sibiraea angustata, Spiraea spp.-Ass. Caragana spp., Berberis amurensis-Ass. Imperata cylindrical. The objective community and objective species were chosen to restore for the different growth form of vegetation. Under the conditions of the vertical distribution regularity was obeyed, the objective community of restoration in subalpine coniferous forest belt was: Ass. Abies faxoniana+(Ass. Rosa omeiensis+Ass. Rhododendron clementinae+orientalis Ribes glaciale)+(Ass. Fragaria gracilis+Ass. Fragaria+Ass. Carex capilliformis); Ass. Picea asperata+(Ass. Rosa omeiensis+Ass. Sibiraea angustata+Ass. Salix cheilophilla)+(Ass. Fragaria gracilis+Ass. Carex capilliformis+Ass. Polygonum hubertii+Ass. Fragaria orientalis). The objective community of restoration in the alpine scrub belt: Ass. Salix cupularis+Ass. Carex lanceolata, Ass. Sibiraea angustata+Ass. Koeleria cristata, Ass. Spiraea alpina+Ass. Carex capilliformis, Ass. Caragana tangutica+Ass. Carex crebra. The objective community of restoration in the alpine meadow: Ass. Imperata cylindrica+Ass. Carex capilliformis. During the time of vegetation recovering, we should develop the multi-hierarchial classification, multi-species, multi-structure community structure of trees, brushes and grasses , increase the comprehensive ability of vegetation resisting external destroying, at the same time, taking kinds of engineering measures to restore the ecosystem of the source region of Minjiang River gradually.