Tree Species Selection In Riparian Zone Of Meishan Reservoir

This paper regarded Meishan reservoir which has the biggest water level difference of Anhui reservoir as study object. According to the existing topography, soil test data and the bareness degree of rock of Meishan reservoir, this paper divided riparian zone into 3 sites such as ramp slopes, steep slopes and rock slopes. Authors studied the tree species selection and cultivation techniques in those 3 sites based on the water level, survival rates of different kinds of plants and growth performance in dry and wet season. We also analyzed the causes of death and decay to find alternative plant species. The results showed as follows:(1) Through the study on characteristics of soil of different sites, we found that the soil water content of three typical kinds of site was low, as also the content of total nitrogen(TN), available nitrogen(EN), potassium(K), calcium(Ca) and magnesium(Mg). The soil was barren with low content of nutrient deficiency, the soil water content of steep slopes was lowest, only about 5.9%, EC value was too low, extremely lack of nutrient, and the soil condition was the most severe, it was not conducive to growth, this site needs soil improvement before planting.(2) The research on plants growth under different waterlogging degrees showed that the growth was different under different water levels. With the rise of water level, the time of waterlogging became shorter and the depth became shallow, the plant growth improved, and the drought stress became seriously, the plant growth reached the maximum value under 4 months waterlogging, which could find that the water level under 4 months waterlogging every year is the most suitable for growth.(3) We found that different plants had different growth, but the growth was similar when at same water levels. Salix babylonica was poor and could not adapt to the reservoir environment, its survival rate was lowest. The best one was Salix matsudana, its survival rate was highest. The sequence of survival rate of the tree species was Salix matsudana >Metasequoia glyptostroboides >bamboo willow >Sapium sebiferum > Liquidambar formosana > Salix babylonica.(4) According to the research on vegetation restoration of different sites, we found that under different site conditions, the growth was different. The growth of ramp slopes was best because of small slope, low rate of bare rock and good soil condition. On contrary, the growth of steep slopes was bad. The slope of rock slopes was about angle, influenced little by water erosion, by filling soil to make the soil improved, and the growth of plants was good.(5) According to the study on the field test of vegetation restoration and other relevant research, we concluded that different site should select different kinds of plants. Amphibian grass like Cynodon dactylon and Lolium perenne had strong recovery growth ability after flooded because of active meristem, this kind of grass was suitable for planting in the lower region with water levels between 114 m and 116 m with above 10 months waterlogging every year; Trees like Salix matsudana and Metasequoia glyptostroboides could be planted in the middle region with levels between 116 m and 118 m, which was waterlogged above 7 months every year and grass was also suitable for this region; Climbing vines like Jasminum nudiflorum and Euonymus fortunei had good landscape effect and small cost, but did not have tolerant of waterlogging, they could be planted in the high region combined with trees at water levels above 119 m which was waterlogged only about 4 months every year.