The Research Of Spatial Distribution And Correlation Of C、N、P、 Ca In Three Typical Forest Stands Of Liaoning Province

This paper takes three typical forest stands in Liaoning province (Chinese pine artificial forest, mongolian pine artificial forest and oak natural forest) as the research objects, and then establishes 69 survey sample plots in western and eastern Liaoning to obtain the soil surface layer, subsurface sample and tree leaves sample. Based on the determination of soil organic carbon, total nitrogen, available nitrogen, total phosphorus, available phosphorus and water-soluble calcium content and forest tree leaves total calcium content, it makes an analysis of the spacial distribution characteristics and trend of each element content in soil and tree leaves total calcium content, and relationship between C, N, P in soil and soil water-soluble calcium content, and relationship between tree leaves total calcium and soil soluble water-calcium content, as well as the absorption strength characteristics of trees to soil water-soluble calcium. Now it comes to the following conclusions:(1) The content of organic carbon, total nitrogen, available nitrogen, total phosphorus and available phosphorus of three kinds of forest stands soil in eastern Liaoning is higher than that in western Liaoning, and both of them show a significant positive correlation with the longitude. This is because that it is lack of rainfall in western Liaoning, its forest ecosystem structure is simple, the productivity is low, the specie diversity is less, and water and soil loss is more severe. And it has a plenty of rainfall in eastern Liaoning, coupled with a relatively humid climate, it provides a good natural environment for most plants, and it has a large number of plant species, a much more complete forest ecosystem structure, a high productivity, as well as a large quantity of restitutions for litter. In addition to the soil total phosphorus, the content of soil organic carbon, total nitrogen, available nitrogen, available phosphorus in the surface layer is significantly higher than that in the subsurface layer.(2) The amount of rainfall and soil water-soluble calcium leaching show a gradual decrease trend from eastern Liaoning to western Liaoning. As a result, the content of soil water-soluble calcium is increasing, and it has a significant negative correlation with longitude. Also, it has a significant positive correlation between the forest tree leaves total calcium content and soil water-soluble calcium content so that the forest tree leaves total calcium content has a highly significant negative correlation with longitude. In a word, the total calcium content of three species of forest tree leaves in western Liaoning is higher than that in eastern Liaoning. And the differences of total calcium content of Chinese pine and mongolian pine leaves between western Liaoning and eastern Liaoning are extremely significant, and the differences of total calcium content between oak leaves in two regions are also significant.By studying the absorption intensity of forest trees to soil water-soluble calcium, it has been found that the absorption intensity of forest trees to soil water-soluble calcium is increasingly strong when the soil water-soluble calcium content reduced. Also, the absorption intensity of forest trees to soil water-soluble calcium decreased and gradually tended to be stabilized when the soil water-soluble calcium content increased. This kind of law is more obviously reflected in natural oak, which has a significant power function relationship.(3) The soil water-soluble calcium content in each forest stand shows a significant negative correlation with the content of soil organic carbon, total nitrogen, available nitrogen, total phosphorus and available phosphorus. The rainfall in western Liaoning is less than that in eastern Liaoning. And the content of C, N, P in soil shows a gradual increase trend from western Liaoning to eastern Liaoning, and the content of soil water-soluble calcium shows a gradual decrease trend from the western Liaoning to eastern Liaoning. Therefore, there will be a law that the content of soil water-soluble calcium is gradually reducing with the increase of soil nutrient.