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摘要: 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 mgm-2h-1)和ACp (134.65 mgm-2h-1)土壤CO2通量显著高于Tp(111.39 mgm-2h-1)和THp(108.53 mgm-2h-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12.45 gm-2h-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3参29Abstract: 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 plantations showed that CO2 and N2O fluxes varied widely during the year,exhibited a relatively high level during the rainy season,and kept a relatively low level in the dry season. Also,peak CO2 and N2O fluxes appeared in the rainy season. Compared to Tp and THp,significantly(P<0.05) higher values of microbial biomass carbon (MBC) were found in EUp and ACp with CO2 fluxes also significantly(P<0.05) higher. The fastest NO3-N uptake was in EUp as were the lowest soil N2O fluxes. These results indicated that soil temperature,soil moisture,MBC,and soil substrate(NO3-N and soil organic carbon,SOC) could be important controlling variables for soil CO2 and N2O fluxes.[Ch,2 fig. 3 tab. 29 ref.]
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Key words:
- soil science /
- soil CO2 fluxes /
- N2O fluxes /
- pure plantations /
- mixed plantations /
- reenhouse gases /
- forest management practices
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链接本文:
https://zlxb.zafu.edu.cn/article/doi/10.11833/j.issn.2095-0756.2011.01.005
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