| Ecology system was destroyed due to construction of highway.Planting artificial vegetation community is not only as an effective compensation way to ecology along the highway but also a good method to enhance the stability of slope.The vegetation community plays a critical role in keeping the stability of slope.So the stability of vegetation community has a close relation with the stability slope.Right now,the method focused on the recovery of highway slope have matured.However it lacks a long time monitor and study in the vegetation community on highway slope,and lacks an evaluation method for the stability.There was a three-year monitor of 11 typical slope vegetation communities in XinyangNanyang highway(form west to east)and 5 typical vegetation communities in Fugou-Xiangcheng highway were carried out in this study.Firstly,the structure and dynamic change of vegetation community were analyzed.Secondly,gray relational grade theory was used in analyzing the coupling for the plant diversity and soil properties.Thirdly,environment factors,vegetation community factors(including the stability of vegetation community),soil factors(including of the coordination between soil and vegetation community diversity)and the ecological service function were chosen in AHP fuzzy comprehensive evaluation method to evaluate the recovery effecting of highway slopes.At last,two methods were used in evaluating the stability of vegetation community.One was named M.Godron method,another named subordinate function value of fuzzy mathematics.In the second method,there were 16 evaluation factors in 5 indices which included species diversity,biomass of vegetation communities,the soil fertility(soil moisture and soil nutrient)and artificial interference.Then the two methods were compared and the stability vegetation community was analyzed,hoping to find the best method in evaluating the stability of slope vegetation community.The main conclusions:(1)In China,Highway is a special road style.There are many slopes in the building of highways,such as fillslopes and cutslopes.In this study,the highway slope ecosystem was defined.It is that lots of bare slopes were generated from the highway construction,a special ecosystem was generated after the artificial vegetation were planted in these highway slopes.The study of slope ecosystem contain the water,soil,vegetation,wind,slope position and slope aspect,etc.(2)The character and dynamic change of vegetation communitythe study of characters and dynamic change of vegetation community shows that the bushes have a high domination position especially the Amorpha fruticosa,this plant has strong competitiveness and keep invading to the other community which beside it.Because of weeds invade,the important value of herb become lower and lower,some of them which were disappeared during the succession of the the artificial vegetation communities.The dynamic change of vegetation community was different in those vegetation community.The vegetation community which had high diversity were Pyracantha fortuneana vegetation community,Broussonetia papyrifera + Amorpha fruticosa vegetation community and Festuca elata + Vicia sepium vegetation community in Xinnan highway.The Bidens pilosa + Lolium perenne + Artemisia argyi vegetation community had a high diversity in Fuxiang highway.The aspect of slope could influence the succession of vegetation community,normally,the amount of plant in sunny slope was more than shady slope.There was obvious regionalism in species changing on highway slope,the vegetation community in Xinan highway is richer than that in Fuxiang highway.There were arbors at this stage of succession and all of them are native plants.As this reason the structure of the vegetation community were changed.It also showed that the diversity indexes in herb layer were higher than those in arbor layer and shrub layer.(3)The coupling coordination degree between vegetation community and soil in highway slopeThe result of physical and chemical properties indicated that the nutrition of soil in highway slope was very low.The nutrition in 0-10 cm soil layer is more than that in 10-20 cm and the nutrition in shady slope is more than that in sunny slope.The result of coupling coordination degree between soil characters and diversity of vegetation community showed that the Amorpha fruticosa + Festuca elata and Amorpha fruticosa + Duchesnea indica vegetation community in Xinnan highway were superior coordination.There was no superior coordination of vegetation community in Fuxiang highway.(4)The evaluation of recovery for vegetation community in highway slopeBased on the recovery evaluation of the highways,it was found that the slops which have been recovered for 9 year did not have a good recovery result even if most of them have good ability in conservation of water and soil.Effects of most of these vegetation communities were “moderate” and few of them were “serious”.Improving the recovery effect is not only time consuming but also need artificial intervention.Those had high weight in evaluate system are the stability of vegetation community,the biomass of vegetation,the coupling coordination of soil and vegetation,ecological protection,species of vegetation community and high efficient with resource-saving.People could focus on these aspects in artificial interference.(5)The evaluation of stability for vegetation community in highway slopeM.Godron method and subordinate function method were used to evaluate the stability of vegetation communities of highway slopes.The result indicated that the vegetation community of Amorpha fruticosa + Festuca elata in Xinnan highway and the vegetation community of Lolium perenne + Trifolium repens + Melia azedarach,Bidens pilosa + Lolium perenne in Fuxiang highway were stable.Both methods had characteristic.It is easy for the researchers to use M.Godron method if they have the information of all the species and the frequency of species in the vegetation community.Both data of soil and vegetation community are needed when people use the second method.Researchers can chose different method base on their data.Based on the results of the two method,Amorpha fruticosa and Festuca elata are worthy to promote in Xinnan highway,Lolium perenne?Trifolium repns?Melia azedarach?Bidens pilosa?Medicago sativa are worthy to promote in Fuxiang highway.Different life style of Leguminosae could be used in improving the soil and native arbors such as Melia azedarach?Broussonetia papyrifera could be used in plant design.(6)Suitability assessment of these methods which were used in this studyThere is few researches and methods in evaluation of the stability for vegetation community in highway slope.So M.Godron method and subordinate function were used in this study,hoping to find a suitable method for highway slope vegetation community.The results showed that both methods have the similar results.Both methods have special characters.If researchers would like to use M.Godron method,the data of species number and frequencies of each species are needed.This method seems easy to be used.If the researchers have the data both of vegetation community and the soil,and they would like to compare different vegetation communities,the second method will be a good choice.So researchers can choose different method based on their data.The correlation analysis were common to be used to analyze the relationship between vegetation community and soil.But this method is limited to analyze the highway slope which recovered for many years.The coupling coordination degree method were used in this study and the result showed that this method is suitable to evaluate the effect and relation between vegetation community and soil during the succession of highway slope.In the last part of this study,AHP-fuzzy comprehensive evaluation method was used to evaluate the restoration effect.Four factors were used in the evaluate system,they were environment factor,vegetation community factor,soil factor and ecological service function factor.It showed that this method is suitable for highway slope study and easy to promotion. |
PDF Full Text Request