Response Mechanisms of Four Land-use Types to Released CO2 Flux of Soil in North China Plain

摘要

To probe the effect of four land-use types of wood land and wheat land of agro-forestry model, poplar plantation abandoned land and wheat land on the growth and the flux of CO2? the licor-8100 Automated Soil CO2 Flux System was utilized to monitor the change of carbon flux of soil from the four land-use types. The soil respiration (Rs) of them was studied systematically. The results showed that the monthly variation and diurnal variation of Rs of four land-use types was lower and did not change significantly. The average Rs flux of wheat land of agro-forestry model was 0.38umol*m~V, the contribution rate of released CO2flux of soil was 19.71%. The results is 8.47% less than the crop land, 22.28% less than wood land of agro-forestry model and 16.85% less than the plantation abandoned land. The Rs flux of agro-forestry model was 8.55% less than the plantation abandoned land and 2.13% more than wheat land. The relationship of Rs and the factors is not significant except the surface CO2 concentration in winter. The correlativity of surface CO2 concentration and Rs is negative and the coefficient of determination is 0.86. The main factors of Rs are different in different dates. The Rs of different land-use types showed the obvious spatial heterogeneity, the relationship of Rs and vegetation cover is not significant.