华南地区典型人工林土壤二氧化碳和氧化亚氮通量研究

二氧化碳（CO2）和氧化亚氮（N2O）是重要的温室气体,森林土壤是其主要排放源。采用静态箱/气相色谱分析技术对中国科学院鹤山丘陵综合开放试验站尾叶桉Eucalyptus urophylla纯林（EUp）,厚荚相思Acacia crassicarpa纯林（ACp）,10个树种混交林（Tp）和30个树种混交林（THp）等4种林型的土壤CO2和N2O排放通量进行了原位测定,研究纯林和混交林对土壤温室气体排放的影响。结果表明：CO2和N2O排放通量季节波动幅度较大;4个林型土壤CO2和N2O通量在湿季均维持较高水平;通量峰值均出现在湿季,旱季则明显降低,且相对稳定。由于EUp和ACp纯林土壤微生物碳（microbial biomass carbon,MBC）比混交林高,导致EUp（130.67 mg.m-2.h-1）和ACp（134.65 mg.m-2.h-1）土壤CO2通量显著高于Tp（111.39 mg.m-2.h-1）和THp（108.53 mg.m-2.h-1）。在4种林型中,尾叶桉对土壤NO3-N吸收快速,土壤N2O排放通量最低,达12.45μg.m-2.h-1。土壤温度、土壤湿度、MBC和呼吸底物NO3-N和土壤有机碳（soil organic carbon,SOC）]都是影响土壤CO2和N2O通量的重要因子。图2表3参29

Soil CO_2 and N_2O fluxes from four typical plantations in southern China

Carbon dioxide(CO2) and nitrous oxide(N2O),which mainly come from soils in forest ecosystems,are important greenhouse gases.Both CO2 and N2O fluxes in a Eucalyptus urophylla plantation(EUp),an Acacia crassicarpa plantation(ACp),a 10-species-mixed plantation(Tp),and a 30-species-mixed plantation(THp) were measured in situ using a static chamber and gas chromatography(GS) technique at the Heshan Hilly Land Interdisciplinary Experimental Station,Chinese Academy of Sciences(CAS).Results from the four plantation...