| Forest is one of the most important parts on our planet, and the subalpine coniferous forests in western Sichuan are a principal part of Natural Protection Projection in Southwestern China and important ecological screen to the upper reaches of the Yangtze River. So the research of the soil microorganisms, soil nutrient contents and the litterfall decomposition in the subalpine coniferous forests in western Sichuan is significant to China.The study site, Wanglang Nature Reserve, located in Pingwu County, Sichuan province, China. The Reserve was established in 1963 as one of the first four reserves set up for Giant panda protection and as such holds some of the best high altitude primary forest and flora to be seen in China from 40 varieties of rhododendrons to wild roses and meadow flowers. A wealth of bird life and wildlife including endemic Golden Monkey, Red Panda, Leopard, Black Bear and Takin can also be seen. This area has been selected as a representative long-term ecological study site of subalpine forest ecosystems in southwest of China.Seven plots selected from Wanglang Reserve were distributed in different types of forest and at different altitude, and different plot has different microclimate. Soil property, microbial population, soil nutrient content of forest soil were determined in Wanglang Natural Reserve, from May to October 2002 to July 2003, The ecological distribution of three main groups, bacteria, actinomycete and fungi were determined in the forest soils by the cell enumeration methods. Six kinds of physiological groups, including ammoniation bacteria, nitrification bacteria, nitrosification bacteria, aerobic autogenesis azotobacter, aerobic cellulose-decomposing bacteria and anaerobic cellulose-decomposing bacteria were enumerated by the most-probable number (MPN). The cell number of each group was studied in soil profiles in these forests. Each profile was classified into horizon A (humurus layer), horizon B (eluviation layer) and horizon C (parent material layer). The soil nutrient contents of total nitrogen, total phosphorus and total potassium were studied at the same time. And then, the probable correlations between the quantities of microorganisms and soil nutrient content were analyzed.The results suggested that soil water content decreased with the depth increasing, this value of soil water was the highest in plot G1 (coniferous forest), because of the highest altitude. Soil pH value ranged from 6.0 to 7.2, the pH value had no markedly difference among the three horizons ineach plot, and so did that among seven types of forest. The organic matter content in horizon A of plot G2 (coniferous forest) was the highest (193.03a kg-1) in seven plots and the lowest one was in plot G3. horizon C (6.15g kg-1). The content of total nitrogen and total potassium and total phosphorus in seven study sites was ranged from 10.04g kg-1 to 0.40 g kg-1. 60.63 g kg-1 to 22.23 g kg" and 6.27 g kg-1 to 0.66 g kg-1, respectively.The highest quantity of bacteria in plot G3 (birch forest), horizon A was 4.48x107CFU per gram dry soil, the lowest was 1.07x106 CFU per gram dry soil in horizon C in plot Li (Festuca ovina population).The quantity of actinomycetes was from 2.64x104CFU per gram dry soil to 5.56x 106CFU per gram dry soil. And that of fungi was from5.45x103CFU per gram dry soil to 8.51 x105 CFU per gram dry soil.All results through ANOVA showed that, the quantity of each group was very significant different among the A-, B- and C-horizon in each site, but there was no significant difference among seven types forest stands. The total nitrogen content and total potassium content of the three horizons also had most significant difference, but the total phosphorus had no difference. Like the microbial quantities, the nutrient content had no significant difference among the seven different forest stands. There was a significantly negative correlation between the quantity of anaerobic-cellulose decomposing bacteria and soil pH value and significantly positive correlations between the...
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