Influence Of Artificial Promotion Vegetation Restoration On Soil Ecology Characteristics Of Rocky Coastal Protection Forest

This dissertation studied on the typical rocky coastal forest stands in San Men county of Zhejiang province, including mixed stands of Wikstroemia monnula and Loropetalum chinense, Platycarya strobilacea stand, Pinus elliottii stand, Liquidambar formosana stand, mixed stands of Pinus elliottii and Schima superba, mixed stands of Pinus elliottii and Liquidambar formosana, among which mixed stands of Wikstroemia monnula and Loropetalum chinense, Platycarya strobilacea stand are natural vegetation restoration after artificial thinning. Soil ecology characteristics comparison is made between Pinus elliottii stand, Liquidambar formosana stand, mixed stands of Pinus elliottii and Schima superba, mixed stands of Pinus elliottii and Liquidambar formosana stand and an unstocked forest land is chosen to work as a reference. Soil physicochemical property, soil microorganism and soil enzyme activities of different sample stands were calculated. The influence of artificial promotion vegetation restoration on soil ecology characteristics of rocky coast protection forest is discussed based on analysis on relevant statistics. The results are as following:1. The soil moisture content of rocky coastal protection forest is generally low, and decreases correspondingly with the deepening of soil layer. The soil moisture content of Platycarya strobilacea stand after the artificial promotion vegetation restoration is the highest, the 0-20cm soil layer achieves 24.01 percents. The weight per volume of mixed stands of Wikstroemia monnula and Loropetalum chinense is the lowest, the 0-20cm soil layer has only 1.24 gï¹’cm-3. The soil porosity and capillary moisture capacity of these two stands increase, whereas the differences in other sample plots are not so distinct.2,The soil nutrient contents in rocky coastal protection forest are very different, the soil total nitrogen, the hydrolyzable nitrogen, the total phosphorus, the fast-acting potassium and the organic content of six experimental plots are obviously higher than the reference plot. The soil total nitrogen, hydrolyzable nitrogen, total phosphorus and organic content of the mixed stands of Wikstroemia monnula and Loropetalum chinense are the highest and the fast-acting potassium content of Platycarya strobilacea stand is the highest.3,The total soil microorganisms, bacteria, ray fungi and fungi in the mixed stands of Wikstroemia monnula and Loropetalum chinense are the highest. The soil microorganisms of all stands assume the reduced tendency along with the increasing soil layer depth with the great variances in different layers. The cluster analysis obtains that the soil microorganism condition of Platycarya strobilacea stand and Pinus elliottii stand and the two mixed stands are more or less the same and can be classed as one kind. Liquidambar formosana stand and mixed stands of Wikstroemia monnula and Loropetalum chinense become one kind respectively.4,The catalase is even among different stands, other than that, soil sucrase, phosphatase and urease of rocky coastal protection forest are significantly varied, the correspondence variation coefficients of 20-40cm soil layer are all higher than 0.50.The urease, phosphatase and sucrose enzyme activity in the mixed stands of Wikstroemia monnula and Loropetalum chinense are the highest, and the catalase activity in the mixed stands of Pinus elliottii and Liquidambar formosana is highest. The cluster analysis shows that soil enzyme activities of Platycarya strobilacea stand and mixed stands of Pinus elliottii and Schima superba are close, so does that of Liquidambar formosana stand and mixed stands of Pinus elliottii and Liquidambar formosana, which can classed as one kind. Mixed stands of Wikstroemia monnula and Loropetalum chinense become one kind respectively.5,Among all the soil factors in rocky coastal protection forest, the microorganism quantity and ray fungi quantity has significant positive correlation with the organic matter, and ray fungi, total nitrogen and hydrolyzable nitrogen has significant positive correlation with the total phosphorus, the related coefficients are all higher than 0.800. The soil bacteria and microorganism quantity have significant correlations with the total phosphorus, soil bacteria and organic matter. The soil microorganism quantity relates closely with different kinds of enzyme activities, among which it has extremely remarkable positive correlation with the sucrose enzyme activity, the related coefficient runs to 0.907, and has negative correlation with the catalase. The soil microorganism and soil enzyme activity play a very important role in the soil ecology characteristics of rocky coastal areas; especially the soil phosphatase occupies the biggest coefficient in various principal components and can be considered as the main factor.In brief, compared with other stands, the majority of soil ecology characteristics of mixed stands of Wikstroemia monnula and Loropetalum chinense after artificial promotion vegetation restoration demonstrate obvious superiority, and although the majority of soil physicochemical property, soil microorganism and enzyme activity of the Platycarya strobilacea stand have not achieved the level of mixed stands of Wikstroemia monnula and Loropetalum chinense, they all have surpassed or approached that of other experimental stands, and are higher than the reference stands. From this obtains, in the difficult vertical type of rocky coastal areas, the measurements of artificial promotion vegetation restoration can accelerate tree growth after afforestation and thus speed up the progress of rocky coastal vegetation restoration. It could also improve the soil ecological character, which makes the contribution to water soil conservation and ecosystem restoration of coastal areas, and provides the scientific basis for the coastal protective forest system construction.