The Effects Of Snow Disaster On Dynamics Of Soil Respiration And Soil Microbial Biomass Carbon Of Phyllostachys Heterocycla Cv.pubescens Forest In Wuyi Mountains

The 2008 snow disaster in southern China was a huge great natural disturbance to the forest ecosystem. We conducted an experiment in Phyllostachys heterocycla cv.pubescens forest in Wuyi Mountains to understand the influence of snow disaster on major soil ecological factors and soil ecological processes. We divided the damage level of the Mao bamboo forest caused by the snow disaster into three types i.e. heavy, moderate and low level. The results indicated:1.The rate of damaged bamboo in heavy, middle and low level were 43.7%, 21.8%, 10.3%, respectively. The annual mean canopy closure were 0.47,0.68,0.72,respectively. The aboveground biomass input to the ground caused by the snow storm were 2.21, 1.04 and 0.60 kg/m2 , respectively. The out of the number of shoots were 11,8,8 /100m2, respectively. The annual mean soil water content was 37.73%,35.29%,35.97%,respectively. The annual mean soil temperature was13.21℃,12.96℃,12.95℃, respectively. The annual mean soil respiration rate were 3.36,1.98,2.23μmol/(m2.s) in C-treatment and 2.18,1.38,1.46μmol/(m2.s) in T-treatment. respectively. The annul mean soil microbial biomass carbon were 458.76 mg/kg,458.85mg/kg,426.60 mg/kg , respectively. The annual mean water soluble-carbon were 94.46mg/kg,23.46 mg/kg,165.05mg/kg, respectively. there were significant differences in major ecological factors in different damage levels.2.Seasonal variation of soil microbial biomass carbon and soil respiration rate in different damage level were significantly, Seasonal variation of soil respiration rate was significant with maximum in Summer , 6.88,4.17,5.62μmol/(m2.s) in C-treatment and 1.83,0.69,0.86μmol/(m2.s) in T-treatment. respectively. And minimum in Spring, 5.25,2.49,3.60μmol/(m2.s) in C-treatment and 0.68,0.41,0.66μmol/(m2.s) in T-treatment. respectively. Seasonal variation of soil microbial biomass carbon was significant with maximum in Autumn, 2704.92 mg/kg,2271.08 mg/kg,1102.43 mg/kg,and minimum in Summer, 1122.03 mg/kg,659.00 mg/kg,383.60 mg/kg. respectively. Seasonal variation of soil water-soluble carbon was significant with maximum in Spring, 2704.92 mg/kg,2271.08 mg/kg,1102.43 mg/kg,and minimum in Autumn, 1122.03 mg/kg,659.00 mg/kg,383.60 mg/kg. respectively. Water content was significant with maximum in Spring, 40.37%,40.97%,39.96%,and minimum in Summer, 33.48%,28.42%,32.20%. respectively. Soil temperature was significant with maximum in Summer, 40.37%,40.97%,39.96%,and minimum in Autumn, 33.48%, 28.42%, 32.20%. respectively. The canopy closure was 0.20, 0.30, 0.40 , respectively in May 2008. and The canopy closure was 0.59, 0.82, 0.85 respectively in May 2009. soil microbial biomass carbon and soil respiration rate did not come back to the corresponding level after one year.3. The canopy closure was significantly negatively correlated with soil moisture, soil respiration, out of the number of shoots and soil microbial biomass carbon, respectively Soil microbial biomass carbon, soil temperature, soil moisture , out of the number of shoots and soil respiration were significantly correlated with the aboveground biomass loss.Our results indicate that there were significant difference in soil respiration and microbial biomass carbon among different damage levels. The open of the canopy and the input of the litterfall and woody debris to the floor may lead to the changes of soil moisture, soil temperature, soil respiration, and soil microbial biomass carbon, and would alter the biological and ecological processes of the Mao bamboo forest.