The Characteristics And Spatial Patterns Of Soil Microbes In Guangxi Forest

Soil microbe is the most active component of the continent ecosystem, the distribution and dynamic is the one of the main accordance of the forest ecological environment integrating assessment. Soil microbe act as the role of vanguard in the recovery of retrograde ecosystem. It has a indispensible occupation in the material recycling and the power transferring of forest ecosystem, and it also means a lot to the forest nutrient. A lot of ecological problems of forest has occurred in Guang Xi, a province contribute so much to the national forestry, as the pace of development accelerated. It can provide scientific reference to the ecological construct, forest sustainable utilization and sustainable economic development by studying the regional soil microbial features and spatial pattern of Guang Xi forest. Representative forest type was chosen as the object of this research, outdoor investigation and indoor analysis were adopted, the entirely soil microbial characteristics were described using classical statistics, the spatial microbial distribution pattern was illustrated by geostatistics, the relationships between soil microbial parameters were discussed with fractional dimension model. The result shows:(1) The microbial biomass and amount of cyclobalanopsis glauca-Lysidice rhodostegia Hance-wingceltis forest (Ⅰ A2b)located in the middle Guang Xi rocky area consisted of limestone, which is the south semi-tropical monsoon ever-green broad leave forest region, are extremely high. In all forest regions the MBP content is relatively low. Attention worthy is the vary indices of all the soil microbial quotas are high, ranging from41.31-116.72percent. Present intense vary (CV>40%).The total microbial amount of different forest regions are different as the forest type changes. The total microbial amount present a order that:Ⅰ A2b> Ⅱ Alb> Ⅰ Alb> Ⅰ Ala> Ⅰ B2a> Ⅰ A2a> Ⅱ Ala. The fungus account for a relatively low proportion of the three main soil microbial communities, the soil bacteria is the dominant community in Guang Xi forest regions Ⅰ A2a、Ⅰ B2a. The order is:bacterial amount> actinomycetic amount> fungal amount. Bacterial amount account for50%of the total microbial amount, the proportions of actinomycetes and fungus are40%and6%, respectively.(2) It can be told that by the comparison of different spatial interpolations that, the spatial structure of Guang Xi soil microbial biomass and amountis more accurately reflected by normal Krigue interpolation than any other methods.(3) The result of spatial analysis shows:unlike the traditional soil microbe randomly distribution hypothesis, the spatial distribution of Guang Xi forest soil microbe is obvious, present different spatial patterns at different extents. The Nugget/Sill of all the soil microbial indices are below15%except for MBP. That means the spatial variation is mainly caused by the factors such as climate, soil characteristics, parent material, topography and so on. The contribution of random factors to spatial distribution is relatively low. The march of each microbial indices are relatively low except for that of MBN, the rest are relatively big and close. The spatial heterogeneity of them are significant. The evenness of all microbial parameters are good, all the fractal dimension D are larger than1.9. The changes of Guang Xi forest soil microbial biomass carbon, microbial biomass nitrogen, bacterial amount and actinomycetic amount present the same tendency as the longitude and altitude change. Which has a similar structure as the gradient of Guang Xi climate and soil regions.(4)Every soil microbial factors, except for fungus, all have significantly correlations, there are extremely significant positive correlations between altitude, MBC, MBN, and there are also significant positive correlations between slope, exposure and fungal amount. That means the topography factor has a important influence on the soil microbe.(5) There is no fractal relationships between most of Guang Xi forest soil microbial biomass and amount except for soil MBC and soil microbial fungus amount, soil MBP and fungal amount as well as actinomycetic amount. The correlations of which are significant(P<0.05).