Study On Biodegradation Of Forest Floor

Forest fuel is burning basis of forest and also dominating the fire behaviors. It has been considered as a major factor for forest management. Forest ground biomass, as a renewable resource, is dramatically abundant in Daxing'an mountains; however, It caused considerable fires in the past several decades. The decomposition of forest fuel is constricted seriously due to the cold-temperate zone where Daxing'an mountains located in. Hence, how to make ground fuel decomposed quickly without any pollution has been a great concern for modern forestry. The study set up the technical and method of microbe-fireproof ing which is fit for Daxing'anling, under the theory, technology and method of microbiology and forest fire science, through separating, purifying, selecting the germ which can decompose combustible, and preparation for microbial inoculums, and degradable test indoor-outdoor. The research supply a new method for China forest fire prevention, which increase theory and technique. The Result of study as follows.In this paper, the ground fuel in three major forest types (Larix gmelini-Betula platyphylla,Betula platyphylla,Larix gmelini) of Daxing'an mountains has been studied.19strains were obtained through the process of fieldwork, indoor enrichment, separation, purification and culture. After second filter paper degradation test,12strains left because of the superiorities on decomposition. We did the third round test based on Larch pine leaves, then only three fungal being selected with good degradation effect. They are Trichoderma atroviride,Trichoderma harzianum and Penicillin bilaiae respectively after identifying. Another four stains also be chosen for comparison. We inoculated them in the bran medium for spores growing. The bran solid matrix was dealt with through freeze vacuum drying process, then separating the spore powder from wheat bran solid substrate using shaker. The last step before spraying test is making spore powder to spore suspension by adding quantitative drugs that made from bacteria.An indoor trial experiment was done in order to test the performance of every strain in degradation under condition of constant temperature and humidity. Spray9different degradation liquid with three doses (50times,100times,400times) in our study area. Compared with other correspond strains, we got the strains with best effect of degradation which is more suitable for doing field experiment. Several plots were set up for doing spray experiment with different types of strains liquid. The results showed that100times doses of degradation liquid of112532can increase the speed of degradation of lignin in Larix gmelini-Betula platyphylla is7.08times faster than natural process with30days and increasing the speed of degradation of holo-cellulose in Betula platyphylla is10.46times faster than its natural process. Degradation effects were significant.The results indicated that efficient degrading microorganisms can improve the degradation rate of forest fuel effectively. It would be having an important practical meaning if the strains be used to make fire belt and reduce and prevent forest fire.