Microbial Community Structure In Forest Soils At Different Dinghu Mountain And Its Association With Carbon Accumulation Process

At different stages of forest succession, the content of soil organic carbon and thecarbon stock have changed due to the changes of species composition andenvironmental factors. Soil amino sugars are a product of long-term microbialproliferation (It is the main metabolites of microbial cell walls), so the amino sugar insoil can be an indicator that used to evaluate the microbial contribution to soil. In thispaper, the experimental soil samples were taken from Dinghu Mountain. By studyingthe amino sugars at different successional stages and different depths in forest soils inDinghu Mountain, we can explore the relationship of soil microbial communitystructure and carbon accumulation.Now there are four kinds of amino sugars can be quantified (Glucosamine,Galactosamine, Muramic acid, Amino mannose) in soil. By determining and analysisof amino sugars that in forest soil, we can draw the following conclusions:1)Amino sugar accumulation and conversion in soil at different successionalstages of forest is closely related to soil properties and environmental factors indifferent sites. With the increasing depth of soil, the amino sugars in soil showed adecreasing trend, wherein the glucosamine accounted for a large proportion of the totalamino sugar, The trend of Glucosamine, Galactosamine and Muramic acidis incoinsitant with the total amino sugars, which increased with the forward succession offorest i.e., masson pine<needle broad-leaved mixed forest<monsoon forest. This maybe attribute to relatively active microbial metabolism due to more accumulation oforganic matter in long monsoon forest and the forest of conifer.2)Amino sugar concentration in soil organic carbon in soil: The ratio of aminosugars in soil organic carbon and soil amino sugars can be displayed relativeaccumulation of the soil carbon pool. Therefore, the concentration of amino sugar mayindicate microbial transformation as well as the relative contribution of organic matter.The ratio showed the first increase and then decrease with increasing soil depth, which showed amino sugars were easy to stabilize the surface soil organic matter. This ratioshowed increasing trend with the succession carried forward, masson pine <eedlebroad-leaved mixed forest <monsoon, The results showed amino sugars were stabilizeat the top of soil organic matter in forest succession stages monsoon. The reason theone hand is a lot of litter on the carbon input, while the carbon input of fresh activity infavor of microbial decomposition and transformation and stability of residues.3)The ratio of amino sugar and cell wall(GluN/MurA):Glucosamine comesmainly from soil fungi. Muramic acid is the only source of bacteria. Therefore, theratio between the two can be used to indicate the relative contribution of soil microbialamino sugar. As the sampling depth increases, GluN/MurA shows a decreasing trend,which indicates fungi on the surface soil is greater than the contribution of bacterialamino sugars. With the succession of forest forward, which shows an overalldecreasing trend, monsoon<eedle broad-leaved mixed forest<masson pine.