The Influence Of Logging And Prescribed Burning On Soil Nutrient And Microbial Diversity In Pinus Massoniana Lamb Plantation

In this essay a35years old Pinus massoniana lamb plantation was chosen as the research object, this plantation is located at the Cha Lou station in Da Qingshan experiment field of the Experimental Center of Tropical Forestry, Chinese Academy of Forestry. The influence of logging and prescribed burning on the soil nutrient, microbial diversity and microbial amount were studied. This research aim to illustrate the principle of the influence of logging and prescribed burning on the soil nutrient, microbial diversity and the soil heath status, and to provide references to the sustainable management of plantations. The results shows:(1) Logging management increased the soil available N, P, K of the sample plot, but the influence is not significant. Logging significantly increased the total soil N and P, while significantly decreased the total soil K. Moreover, logging significantly increased the soil organic material content. The soil exchangeable Ca and Mg increased after applying logging management, the difference of exchangeable Ca is significant while that of exchangeable Mg is not significant. On the other hand, prescribed burning management significantly increased the soil available N, P, K of the sample plot, while it significantly decreased the soil total N and K. Prescribed burning increased the soil total P, but the change is not obvious. Prescribed burning significantly increased the organic material content as well. On the contrary, it decreased the soil exchangeable Ca and Mg, both of the differences were not significant. After the integrating effect of logging and prescribed burning, the available N, P, K of the sample plot significantly increased. The soil total N and P increased significantly as well, while the soil total K decreased significantly. The soil organic material content of the sample plot slightly increased, as well as the soil exchangeable Ca and Mg. The difference of the soil exchangeable Ca is significant while that of the soil exchangeable Mg is not significant.(2) logging followed by prescribed burning significantly lower the soil microbial species richness, the microbial diversity indices and the microbial species evenness indices. And the two managements extremely decreased the soil bacterial amount, fungal amount and the actinomycetic amount of the sample plot. This means logging and prescribed burning had a tremendous negative effect on soil microbial diversity of the sample plot. Among which, the effect of prescribed burning seems to be not that obvious, that means the microbial community has been through a rapid recovery process right after prescribed burning was applied. (3) The microbial species richness indices, diversity indices and evenness indices had positive correlation with most of the soil nutrient element at a certain level, especially the evenness indices had significant or extremely significant positive correlation with soil available N and P. On the other hand, we can tell that the soil bacterial amount, fungal amount and actinomycetic amount had positive correlation with most of the soil nutrient element according to the analysis about the soil microbial amount and the soil chemical characteristics. Especially the positive correlations between soil microbial amount and soil available N, P and total P are significant or extremely significant.The reserve of the residue that left over after logging and fire intensity control are recommended according to this research. In order to guarantee the fast growing of the subsequent plantation, and, mean while, keep the decrease of soil microbial diversity and amount to the lowest extent. Furthermore, realize the scientific sustainable development.