Study On Evaluation Of Site Quality And Selection Of Green Plants At Langzhuo Highway Roadsides

In the greening of highway, especially in arid and semi-arid areas, soil moisture is the key factor in the success of greening. So in order to solve the continuous and stable development of highway green issue, we must first solve the water problems in the highway greening and only clarify the characteristics of soil moisture in highway, we can have a reasonable selection of plants and irrigation maintenance. For this purpose, in the paper, the temporal and spatial distribution of factors of solar radiation, air temperature and humidity, soil temperature and moisture were studied carefully. On this basis, put forward a multiple non-linear regression model between soil moisture and meteorological factors and Langzhuo Highway site quality evaluation system. Finally, through pot and field experiments, drought green plant species that fit for Langzhuo highway site condition were selected. The results can provide basic information and scientific basis for the greening and ecological environment construction of highway.In this paper, the result of meteorological factors, soil moisture, soil chemical properties were used and combined with the comprehensive principles of the selection of evaluation index. Finally, soil moisture, topography, hardness, organic matter, the lowest month average temperature, extreme low temperature were selected as site quality evaluation factors. The sum of index method was used to establish site quality comprehensive index formula:F= 0.222X1,+0.173X2+0.222 X3-0.131X4+0.253X5-0.064X6Eventually, realized the assessment of site quality at Langzhuo highway and the result was in accordance. The result showed that the most appropriate greening site of Langzhuo highway were ground and central isolation belt and followed by shady slope and sunny slope.Finally, on the basis of site quality evaluation study and combined with common green plants in North China Highways,8 kinds of plant were selected to carry out for selection of drought-resistant plants. Under water stress, the leaf water potential, chlorophyll fluorescence ratio, photosynthetic rate and transpiration rate were studied at pot experiment. And with the field experiments record on the survival of each seedlings, the following findings were showed:under drought conditions, the survival rate of 8 plants arranged in sequence that was Platycladus orientalis (L.) Franco>Buxus sinica (Rehd. et Wils.) Cheng ssp. sinica var. parvifolia M. Cheng (Sabina vulgaris Ant.)> Sabina chinensis (L.)Ant.> Euonymus japonicus Thunb> Rosa cultivars Floribunda> Berberis thumbergii f. atropurpurea Rehd. (Rosa rugosa). According to the result of drought-resistant, it can be combined with several types of drought plant species that adapt to Langzhuo highway green. If the choice of two, they are Platycladus orientalis and Buxus sinica and if the choice of three or four they are Platycladus orientalis, Buxus sinica, Sabina vulgaris, and Rosa cultivars.