| In this paper, we choose the different types of riparian buffers as the research object, to research the configuration type for the removal rate of contaminant, and to explore the optimal configuration type and a minimum width of contaminant removal. The main conclusions are as follows:(1)There are five kinds of everygreen trees in four types configuration at the test, the belonging to five five genera of families; seven species everygreen shrubs in 7genera of 5 families ten kinds of deciduous trees, the belonging to eight ten genera of families; six kinds of deciduous shrubs, the belonging to six genera of six families and. The averge diameter at breast heightof tree species was 4.39 cm,40.00% of the trees average diameter at breast height is greater than 5 cm, the average diameter of trees between four and five centimeter have 26.67%,13.33% of the trees average diameter at breast height between 3-4 cm,20.00% of trees less than three centimeter in there diameters. Shrub tree species of average diameter at breast height was 3.45 cm, the average diameter of trees more than five centimete have 6.25%, the average diameter of trees between four and five centimete have 1.25%, the diameter of trees three and four centimete have 62.50%,18.75% of the trees average diameter at breast height was less than 3 cm.(2) Within the experimental field, through the fifteen kinds of plants’ new branches measured, we found that eight kinds of tree branches growth that S growth curve fitting was the best, and they were Ligustrun lucidum、Quercus virginiana、 Sapindus mukorossi、Ailanthus altissima、Melia azedarach、Robinia pseudoacacia、 Diospyros morrisiana、Euonymus maackii; In S growth curve,six kinds of shrub come out the best result, they were Eurya emarginata、Ternstroemia gymnanthera、 Distylium buxifolium、Rhaphiolepis umbellata、Papermulberry、Ilex Integra。(3)In one years, trees+ shrub+ grass configuration types was the strongest in the removal rate of pollutants, the removal for TN、TP、NO3--N、NH4+-N were 22.07%、 26.10%、29.49%、40.68%, shrub+ grass configuration types have the weakest in the removal, the percentage of removal were 32.00%、46.54%、32.40%、26.45%. And through correlation analysis we found that them were significant positive correlation between the species diversity and the removal rate of pollutants.(4)Under the different widths, trees+ shrub+ grass configuration types still have the strongest removal rate, the removal in lm,2m,4m,7m were 32.26%、36.65%、 41.69%、55.78%, with the exception bare ground outside, trees+ grass configuration types have the weakest removal rate, the removal were 26.10%、30.83%、34.68%、 49.35%. And through correlation analysis we found that them were significant positive correlation between the different width and the removal rate of pollutants (P<0.05).(5)According to the relationship between riparian buffer width and four kinds of different pollutants, we had established the model about pollutant-width, through the model we could calculates the ranges of minimum width of the riparian buffer zone, which was:7.75-18m, and based on riparian buffer width-pollution comprehensive physical model:y=3.318x2+14.427x+12.816, we calculate the minimum width of riparian buffer zone,which was the 12.89m.(6) By taking pictures, we evaluated the beauty of inner and outer landscape. Using the method of contrast, we found that outer landscape have the higher than inner landscape in landscape aesthetic, then by single factor analysis of variance, it is concluded that significant differences between them (P<0.05)... |
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