采伐干扰对东北温带次生林土壤碳矿化和活性有机碳的影响

在黑龙江东部的张广才岭选择典型次生杂木林进行不同采伐处理,一个生长季后测定了土壤潜在碳矿化速率和活性有机碳含量.结果表明:在28℃条件下经过90d的培养,土壤潜在碳矿化速率和碳矿化总量在所测定的土层中(0-10 cm,10-20 cm,20-30 cm)均表现为:50%强度采伐>皆伐后农作>25%强度采伐≌对照>皆伐后造林的变化趋势,但各处理间差异不显著.土壤易氧化碳含量在3个土层50%强度采伐均显著高于对照.土壤微生物碳含量在0-10 cm和10-20 cm土层,50%强度采伐显著高于对照.在0-10 cm土层,皆伐后造林显著低于对照.水溶性有机碳含量在0-10 cm和10-20 cm土层,50%强度采伐显著高于对照,在20-30cm土层,皆伐后造林显著低于对照,这说明在东北温带次生林中,较大强度的择伐短期内可增加土壤活性有机碳含量.而皆伐后造林可导致土壤活性有机碳出现下降趋势.

Effect of Harvest Disturbance Oil Soil Carbon Mineralization and Soil Labile Organic Carbon in the Temperate Second Growth of Northeast China

Responses of the potential carbon mineralization and labile organic carbon of soil to different harvest methods after a growing season were measured in second shaw growth of Zhangguangcai mountain in Heilongjiang province.The results showed:after 90 days of incubation,at 28℃,the potential mineralization rate and cumulative mineralized amount of soil organic carbon(SOC)from different plots range as follow:partial cut I(50% of the stand volume removed),cropland(farming after clear cutting),partial cut II(25%of the stand volume removed),uncut,afforestation(forestation after clear cutting).There are no significant differences among different harvest methods.The amount of soil readily oxidation carbon(ROC)of partial cut I in all the three soil horizons is significantly higher than uncut.The amo unt of soil microbial biomass carbon(MBC)of partial cut I in the 0-10 em and 10-20 cm soil horizons is significantly higher than uncutl; in the 0-10 em soil horizon,the amount of MBC of afforestation is significantly lower than uncut.The amount of water-soluble organic carbon(WSOC)of partial cut I in the 0-10 cm and 10-20 cm soil horizons is significantly higher than uncut,in the 20-30cm soil horizon,the amount of WSOC of afforestation is significantly lower than uncut.The results suggests that after partial cut with greater intensity in short-term,the amount of soil labile organic carbon will increase,but after forestation following clear cutting it will decrease in the temperate second growth of northeast China.