The Soil Biochemic Characteristic Of Water Protection Forest In Huangqian Reservior Watershed

This article regards water boundaries of municipal water source -Huangqian district as studying area, typical forest vegetation-the sunny side of the mixed forest of Pinus tabulaeformis and Acer mono Maxim, the shade side of the mixed forest of Pinus tabulaeformis and Acer mono Maxim, Quercus acutissima, Castanea mollissima, Platycladus orientalis in the area as the research object, and in contrast to grassland. Mainly discuss the physical and chemic characters, the soil microorganism and the soil enzyme activity, and them spatio-temporal variability. so to offer the theory basis and technique for selecting the tree of the water conservation forest and programming the forest structure.The mainly study results are:(1) The soil chemical element①the chemical element,amount of soil microorganism and oil enzymatic activity of different forest.the five forests/ chemical elements (include the soil organic matter, the available K, the soil P, the available P, the soil N, the available N), amount of soil microorganism and oil enzymatic activity are higher than grassland. In the ecological forests, the chemical elements of Quercus acutissima forest are biggest, and the Platycladus orientalis forests/ are lowest. The study results show that: the forest can improve the soil condition, and can improve the chemical elements content of soil.②the spatial variety of chemical and microorganism elementThe chemical elements of surface layer soil are all higher than the under layer soil /s among the different forests (except the soil P) .the soil chemical elements of different forests, are influenced by the vegetation, the soil quality, temperature et. And at the same time, the decompose velocity of litter and the amount of returned nutrient are the main influencing factors. There are different amounts of soil microorganisms in different soil layer. The numbers of three soil microorganisms (microbe, fungi, actinomyces) in surface soil layer are smaller than them in under soil layer. For example, the average number of soil microorganisms (microbe, fungi, actinomyces) in surface layer is more than under layer to 30.50×107, 75.00×104, and 313.31×105. The maybe has the connection with that the surface has much soil nutrition elements. Contemporary there is a large number of roots. And the soil has the fit water and breath condition. So in the surface soil layer, the amount of soil microorganisms is larger.The study result show that the four soil enzyme activity in surface soil layer all are stronger than then in under soil layer. For example, the average number of soil enzymatic (catalase, urease, polyphenol-oxidase and phosphatase ) in surface layer of different forests are 0.19mg/g,0.09 mg/g,0.16 mg/g和9.92 mg/100g,but in under layer, they are 0.14mg/g,0.05 mg/g,0.10 mg/g和6.56 mg/100g. The first four number add to0.14mg/g, 05 mg/g, 10 mg/g,.56 mg/100g than the later.③The temporal variety of chemical and microorganism elementsThe soil chemical elements change with the seasonal change. The organic matter, the available K, the soil N and the available N have the same change characters. The amount of them is highest in Oct and Apr. The amount in Aug and Dec. But the soil P is highest in Aug. In Dec, the amount of P is lower than in Aug. During the Apr and Oct, there are lest P. This change character is according to the change character of phosphatase.The soil microorganisms change with the seasonal change. The change character of microbe and actinomyces all are double peak value curves. The amount of microbe and actinomyces is biggest in Oct and Apr. The amount in Aug and Dec is smaller. But the amount of fungi/s change character is: Dec>Oct>Apr>Aug. Because of the microbe is the largest part of the total number soil microorganisms, so, the total soil microorganisms/ change character is same with the microbe.The soil enzymatic activity of different forest change with the seasonal change. The Result show that: the soil catalase of different forests all are still increase from Apr to Dec. This because the catalase has the correlation with the the decompose velocity of litter. With the amount of decompose litter become larger, the amount of catalase increase.The urease are the double peak value curves, the urease activity is strongest in Oct and Apr. he urease activity is lower in Dec and Aug.The polyphenol-oxidase activity is strongest in Dec and Apr. the polyphenol-oxidase activity is lower in Oct and Aug.The temporal variety of phosphatase activity is same with urease.(2) The correlation analysis of the soil Biochemic Characteristic①the correlation between the soil microorganisms and the soil chemical elements The microbe has the distinct correlation with organic matter and available K. And at the same time the correction reach the distinct level. And the correlative quotiety are 0.874**,0.932**.But microbe has not the obvious correlation with the N, available N, and the P. But it has not correlation with the available N. The fungi have the same correlation as the microbe. But the actinomyces has the correlation with the soil chemical elements, but all of them have not reached the distinct level.②the correlation between the soil enzymatic activity and the soil chemical elements The polyphenol-oxidase activity has the negative correlation. The catalase has the correlation with the chemical elements, but only the correlations with the organic matter and the available K, reach the distinct level. The urease and the phosphatase have the same correlations with the soil chemical elementents as to the catalase.③the correlation between the soil microorganisms and the soil enzymatic activity The result shows that: the three soil microorganisms and the soil enzymatic activity have the nearly correlation. And at the same time, among the three soil microorganisms, there are nearly correlations. The soil enzymatic activity also. The correlations show that the among the soil microorganisms, they interdependent.Above all, In water protection forest of Huangqian reservior watershed, the physical structure and the biochemic characteristics of the broad-leaved forest and the conifer×broad-leaved mixed forest are obviously better than the pure conifer forest, the economic forest and grassland. So, the huangqian valley as one of the important source, should strengthen the three planting work. And try to reduce the amount of grassland or economic forest. In the work of cultivate and manage the forest , first of all we should build the broad-leaved forest consisted by the Quercus acutissima et. Second build the mixed forests consisten mainly by Quercus acutissima, Pinus tabulaeformis, Acer mono Maxim. And plant the broad leaf tree in the Platycladus orientalis forest, so as to change it into the conifer×broad-leaved mixed forest.