[Effects of selective cutting on soil respiration in conifer/broad-leaved mixed forests in Xiaoxing' anling]

By using LI-8100 CO2 Flux Meter, the CO2 flux of soil surface and the temperature and moisture content at soil depth of 10 cm in conifer/broad-leaved mixed forests under different intensity of selective cutting in Dailing Forest Bureau of Heilongjiang Province were determined simultaneously from 2003 to 2007, with the changes of soil surface CO2 flux after selective cutting and their affecting factors studied. The results showed that the CO2 flux was correlated with soil temperature and moisture content, with a relatively high confidence ranged from 68% to 98%. Selective cutting increased the CO2 flux, with an average annual increment being from 7.17% to 26.89%. There was a significant quadratic correlation between soil surface CO2 flux and cutting intensity (R2 = 0.961). Soil organic matter content and cutting intensity were the main factors affecting the changes of soil surface CO2 flux after selective cutting.