Compositive Evaluation On Adaptability Of Securing Plants And Compound Vegetation On Slope Of Highway In Subtropics Of China

The adaptability of securing plants and compound vegetation on slope of highway in subtropics of China is studied, to probe the important meanings of vegetation preventive on slopes of highway protection. The experiment is divided into two parts.The first part is to selection 16 plants,including kummerowia striata,Lotus corniculatus,Cajanus caja,Indigofera pseudotinctoria etc leguminous plants, and Cynodon dactylon,Vitex negundo etc other family plants. The second part is the experiment of compound combination:namely,A: Eragrostis curvula (60%) + Lotus corniculatus(20%)+ Trifolium repens(20%),B:Cynodon dactylon(60%)+ kummerowia striata(20%)+ Lotus corniculatus (20%),C: Festuca arundinacea(40%)+ Festuca rubra (20%)+ Vitex negundo(15%)+ Lespedeza formosa(10%)+ Indigofera pseudotinctoria(15%),D: Festuca arundinacea (40%)+ Festuca rubra (20%)+ Indigofera pseudotinctoria (15%)+ Rhus chinnensis (15%)+ Robinia pseudoacacia (10%)。Twenties indices were mensurated, including phenophase,adaptability,plants community and soil corrosion etc.The principal components analysis and subject function etc statistical methods were used to evaluate the adaptability of 16 plants and preservation effect of 4 compound combination .The main conclusion is as follows:1.The most important indices of evaluation adaptability of plants on side slope of highway are: coverage , aboveground biomass, underground biomass, drought resistance, length of taproot, green time, growth height, seedling rates,tiller ability and density.2.The sixteen plants are firstly divided into six types according to evaluation grades and subject function statistical method:the first type is Cajanus cajan and Crotalaria mucronata,the best adaptability ,which can be used pioneer plant or constructive species; the second type is Cynodon dactylon,the better adaptability, which can be used constructive species ;the third type is Eragrostis curvula, Paspalam notatum,which can be used constructive species on rotten rock slope ; the forth type is kummerowia striata,Lotus corniculatus and Vitex negundo.The adaptability is centered,and can be used protection species and auxiliary species;the fifth type is Robinia pseudoacacia,Eremochloa ophiuroides,Vitex negundo,Lespedeza formosa,Leucaena leucocephala,Desmodium sequax, Rhus chinne- nsis,which can't be plant singly and be used accessory species;the sixth is Trifolium repens,which can be used pioneer plant.3.The compound plant communities is stabile,and the construction of plant communities is reasonable. The distribution shape of aboveground biomass is like a pyramid upward and that of underground biomass is like a pyramid lying upside-down. The seasonal distribution of aboveground(underground ) biomass can be described by quadratic equation in each compound...