Research Of Light Environmental Characteristics And Vegetation Quantity For Road Ecology Greening Plants Communities

Road ecological greening means that during protecting the background ecological environment, natural restoration first and assisted by artificial restoration, by reasonable engineering measures and plant materials, to establish stable community, ensure traffic safety, restoration ecology environment, promote landscape coordinated, and construction harmony greening way between man and nature. Many species of plants, stable community and harmony road ecology environment is its characteristic and target. The paper taked WinSCANOPY For Canopy Analysis to collecting data, studied and analyzed light environmental characteristics indexes of Populus tomentosa and Salix babylonica communities, vegetation quantity and relationship between them. The results showed that:(1)The standard deviation of Gap Fraction, MLA and LAI is too small, and some is close to zero, such as Site Factor, PPFD and so on. It means that test method is stable enough to analyze community light characteristics and canopy structure.(2) The total radiation and scattering radiation were basically same for the two communities, but the direct radiation and total radiation under the canopy decreased with DBH increasing. The gap fraction of Populus tomentosa communities firstly decreased and then increased with DBH increasing, but it decreasd with DBH for Salix babylonica communities and the average of the latter was lower than the former. LAI increased with DBH increasing for two kinds of communities, and the average of Salix babylonica communities was bigger. We concluded that the light environment of Populus tomentosa communities changed larger apparently than that of Salix babylonica communities, and the latter was more suitable for establish multi-layer vegetation system for road greening if light was the only factor taken into account. (3) By analyzing the relativity, the paper thought that there is an obvious correlation between diameter and vegetation quantity and vegetation quantity and extinction degree.(4) Therefore, the paper studied on green quantity ratio of common road greening plants and different allocation models and constructed green quantity ratio models of 25 plants, it provided basic analyzing and reference for road greening. The results showed that: the green quantity ratio of broadleaf forest was between 3.02 and 4.80, the one of coniferous forest was between 4 and 6. The green quantity ratio of shrub was relatively small, but that of close planted hedge reached 3.94; The size order of different communities green quantity ratio was that: mixed wood>broadleaf forest> coniferous forest>shrub communities.(5)At last, the paper think that in road greening construction, we could promote the economic benefit, ecology benefit and landscape benefit, by plating high vegetation quantity and high extinction coefficient plants.