择伐对小兴安岭针阔叶混交林土壤呼吸的影响

Effects of selective cutting on soil respiration in conifer/broad-leaved mixed forests in Xiao-xing' anling.

利用LI-8100土壤CO2排放通量全自动测量系统，测定了黑龙江省带岭林业局东方红林场不同采伐强度林地的土壤表面CO2通量和土壤表层10cm处的温度和湿度，研究了择伐作业后林地土壤表面CO2通量变化及影响因素．结果表明：伐后林分土壤温度和湿度与土壤表面CO2通量季节变化呈较好的相关关系，解释了土壤呼吸的68％～98％；择伐作业使林地表面CO2通量增加，年均增幅在7．17％～26．89％；采伐强度与土壤表面CO2通量呈显著的二次相关关系（R^2=0．961）．土壤有机质含量和采伐强度是导致择伐后土壤表面CO2通量变化的主要影响因子．

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 （R^2 = 0. 961 ）. Soil organic matter content and cutting intensity were the main factors affecting the changes of soil surface CO2 flux after selective cutting.