The Research Of Change Rule And Characteristics Of Soil Microbial Metabolism And The Important Indicators Of Organic Carbon At Different Altitude

This study analyzed the mechanism of change of vertical zonal and growing season dynamic for the soil microbial biomass carbon (SMBC), microbial biomass nitrogen(SMBN),6 kinds of extracellular enzyme activity and difference changes of soil active organic matter content and discusses the relationship of the soil microbial biomass, soil enzyme activity and soil organic matter with the soil nutrient. in the primitive Korean pine forest of Changbai at 5 elevations between 700-1200m.1) The results showed that the SMBC and SMBN and the ratio of SMBC and SMBN had the same trend which are all increased and then decreased along with the altitude. The soil microbial biomass carbon, nitrogen and the ratio of SMBC and SMBN reached the highest at 900 m (1287.18 mg·kg-1; 224.29 mg·kg-1; 9.29). There is a significant difference of the SMBC and SMBN between the elevation (p<0.05). The carbon and nitrogen content of the microbial biomass decreased along with soil depth. In the growing season (from May to September), the SMBC and SMBN in the A soil layer increased and then decreased again. But the SMBC and SMBN first increased and then decreased which became unimodal shape in the B soil layer. The seasonal variation of microbial biomass carbon-nitrogen ratio between different altitudes and different soil layers are difference. In addition to a low in May, the microbial biomass carbon-nitrogen ratio was between 5 to 20. The physical and chemical properties of soil has a significant correlation with the content of the soil microbial biomass carbon and nitrogen at different altitudes.2) There is a relatively uniform impact on soil enzyme activity by Korean pine. Each of soil enzyme activity has no significant difference between different altitudes. In addition to the acid phosphatase, the other 5 kinds of enzyme activity decreased along with soil depth. Throughout the growing season, polyphenol oxidase, sucrose activity are highest in May and August respectively. Catalase, cellulase and acid phosphatase activities were higher in September. There is a significant difference of acid phosphatase, urease and polyphenol oxidase between months. The organic composition of soil and environmental factors has a significant relationship with soil enzymes. The soil effective nitrogen is an important factor regulating the soil enzyme activity.3) Throughout the growing season, the dissolve organic carbon of each elevation had the trend which was decreased and then increased along with the altitude. There has significant difference between each month, the highest in May, the lowest in August. During the spring and autumn, the composition of soil humus content of elevation has different changes, each index at 900 m was the highest. Overall, the trend that were first increase and then decrease. Humus, humic acid and humin were the significant difference between elevations (p<0.01). EE-GRSP in soil showed a trend of gradually reduce with increasing altitude. The highest value is 2.04 mg·g-1 at 700 m and the lowest value is 1.24 mg·g-1 at 1100 m. T-GRSP in soil showed a trend which was first increased to reduce and then rising again along with the altitude. The highest value is 14.5 mg·g-1 at 900 m and the lowest value is 6.52 mg·g-1 at 1100 m. There was significant positive relationship between soil effective phosphorus, EE-GRSP and polyphenol oxidase, sucrose (p<0.01) at A soil layer. There was significant positive relationship between soil effective K with humic acid at B soil layer (p<0.01).