Study On The Manmade Plants Community For Ecological Restoration Along The Slope Of Litan Expressway In Hunan Province

In order to understand the restored condition about manmade plant community of side slope on Liling-Xiangtan expressway in Hunan province, many factors are analyzed based on the principle of phytocoenology and typical sampling method, which include the number of total plant community coverage, the species, the species composition, the separate species coverage, the community species diversity, the height of species, the species of ground diameter from the arbor layer, shrub layer and herb layer. Ecological characteristics of restored condition about artificial plant community is analyzed through7aspect which are the species composition, the community structure, the floristic geographic analysis, the types of plant life, the important value of species, the intensity of competition with same or different species, the ecological niche and the niche overlap value. Results are showed as follows:(1) There are a total of24species in whole community, belonging to15families,22genera. The species include9the arbors,12the herb,3the liana. The species of compositae family is amount5which is the largest number of species. Followed by oleaceae family and grasses family, each have3kinds of species and then there are2kinds of legume.(2) Amount15branches can be divided into4type distribution. The largest number of the branch is the Cosmopolitan and Pantropic.22genera are divided into7areas and1variant. North temperate distribution is dominant in genus.(3) Vertical structure of community is largely consist of arbor, shrub and herb. Arbor layer is single relatively and Pinus massoniana is dominant. The shrub layer is given priority to with Ligustrum quihoui and Ligustrum sinense. Herb layer is consisted by a variety of plants.(4) In the shrub layer, the important values of Pinus massoniana, Ligustrum sinense. and Ligustrum quihoui are29.79,19.7,33.7, respectively. These are far more than other species in the community. Important value of Ligustrum quihoui is maximum. Ligustrum quihoui and Pinus massoniana Lamb show strong applicability in community of artificial restoration. Important value of Neyraudia montana Keng which is maximum is19in herb layer. Followed by the Trachelospermum jasminoides-. Trifolium repens and Macrothelypteris toeeessiana, their important values are respectively14.9,11.6,8.7. Important value of herb layer is smaller, but it enriches the diversity of community.(5) Through the calculation ability of interspecific competition, we learned that average competition index of Pinus massoniana, Ligustrum quihoui and Ligustrum sinense. were0.12,0.13,0.15. Three competitive powers are close. Compared with Robinia pseudoacacia L which average competition power is0.28, their average competition powers are similar. It shows that the three competitive ability is stronger than Robinia pseudoacacia L. Original plants such as Spanish dagger have died. Analysing the calculation ability of intraspecific competition of Pinus massoniana, Ligustrum quihoui and Ligustrum sinense, it showes that three plants’competition powers are the strongest in4-5.5cm,6-8cm,5-7cm in diameter respectively. They belong to their respective advantages layer, thus conclusion is learned that the three kinds of competitive powers are proportional to the level Ligustrum sinensef ground diameter. Through the calculation formula of niche breadth, niche breadth of Pinus massoniana, Ligustrum quihoui and Ligustrum sinense are4.435,3.778,3.69, respectively. Size order:Pinus massoniana> Ligustrum quihoui> Ligustrum sinense. Analysing the niche overlap, the niche overlap value between Pinus massoniana and Ligustrum quihoui, Pinus massoniana and Ligustrum sinense, Ligustrum quihoui and Ligustrum sinense respectively are0.65,0.68,0.869. Three plants’overlap value is above0.6. These explain that the requirements of living environment of Pinus massoniana, Ligustrum quihoui and Ligustrum sinense are basically the same. These can be adapt to the side slope well on Liling-Xiangtan expressway in Hunan and actual situation also is consistent with them.In generally, Pinus massoniana, Ligustrum quihoui and Ligustrum sinense are similar to the requirement of living environment. These three kinds of plants can effectively adapt to the side slope environment of highway and also can obtain good effect of ecological restoration.