Soil Nutrient, Microbial Biomass And Soil Enzyme Activity Of Four Community Types Of Evergreen Broad-leaf Forest On Yuexi, Anhui Province

As the supporter of plant living, forest soil make a great contribution in stabilizing and supporting plants. It has positive significance that to understand the characteristics of forest soil fertility and health by studying the soil nutrient status and the characteristics of biological activity index. This study is based on evergreen broad-leaved forest and its derivative community in the laurel forest zone of Yuexi county, Anhui province. We analyzed the various index of the soil in the above four community types, such as physical and chemical properties, microbial biomass, soil enzyme activity, and we also revealled their distribution pattern and change dynamics with season variation, we also compared the vary impact of different community form on the contents of various soil element. This study is not only helpful in further explained the relationship between soil nutrient and soil biological activity index but also can form the grounds for making measures to improve vegetation productivity and keep soil fertility. The main research results are as follows:(1) The different of physical and chemical properties, microbial biomass, enzyme activity of soil on four community typesSoil pH in four community types range from 4.57 to 5.81 in the 0-40 cm soil layer, that are acidic soil. The moisture content range from 25.75 to 28.73 percent in the 0-40 cm soil layer of four community types. The content of organic matter, total carbon, total nitrogen and nitrate nitrogen of soil are most in evergreen broad-leaved forest, and these of in mixed broadleaf-conifer forest and Chinese fir forest are relatively low. But total potassium (12.05～25.51 g/kg), rapidly available potassium (66.48～135.58 mg/kg) contents in Chinese fir forest are most compared to others. Ammonium nitrogen and available phosphor of soil are most in phyllostachys edulis forest, specially. Microbial biomass carbon in mixed broadleaf-conifer forest is more and microbial biomass nitrogen in phyllostachys edulis forest is more. Soil microbial biomass is more in evergreen broad-leaf forest than that in Chinese fir forest. Enzymes activity in the broad leaved forest is higher than that in coniferous forest.(2) The discrepancy of different soil depth on physical and chemical properties, microbial biomass, enzyme activity of soil.Soil pH and moisture content increased significantly with the increasing of soil depth in four community types. Soil nutrient, microbial biomass and enzyme activity significant reduced with the increasing of soil depth in four vegetation types, while except the acid phosphatase and total potassium. Significant difference was found in the soil index contents between different soil layer.(3) The seasonal dynamics of nutrient elements, microbial biomass, enzyme activity of soil on four community typesFor 0-40 cm soil layer, soil organic matter, total carbon, total nitrogen, total phosphorus, total potassium in content of four community types were 7.11～56.45 g/kg, 1.23～6.67 g/kg,0.52～2.69 g/kg,0.02～0.43 g/kg,2.68-25.71 g/kg, respectively. For 0-40 cm soil layer, ammonium nitrogen, nitrate nitrogen, available phosphorus and available potassium in content of four forests were 2.53～50.73 mg/kg,0.25～8.23 mg/kg,4.11～17.20 mg/kg,45.11～135.58 mg/kg, respectively. As a whole, soil nutrient contents were higher in summer and autumn and relatively lower in spring and winter under four kinds of forest vegetation types. In terms of biological activity index:for 0-40 cm soil layer, microbial biomass carbon, nitrogen, phosphorus in content of four forests were 86.97～909.57 mg/kg,14.35～202.15 mg/kg,11.99～92.56 mg/kg, respectively. For 0-40 cm soil layer, activity of urease, invertase, acid phosphatase, catalase of soil of four forests were 0.16～0.98 mg/g·24h,6.13～32.86 mg/g～24h,0.09～0.73 mg/g～2h,1.05～1.95 ml/g·20min, respectively. Microbial biomass and enzyme activity of seasonal dynamics are similar to seasonal fluctuation regularity of nutrient content. That soil biological activity index in terms of improved soil nutrient was significant, and closely linked to soil nutrient, mutual influencing, common deciding of soil fertility.