华南丘陵区农林复合生态系统早稻田CH_4和N_2O排放通量的时间变异  

Fluxes of CH_4 and N_2O from paddy field of agroforestry ecosystem in hilly area of South China in the first crop season

作　　者：刘惠[1] 赵平 林永标 饶兴权 王跃思[2] 

机构地区：[1]中国科学华南植物园 [2]中国科学院大气物理研究所,北京100029

出　　处：《生态环境》2006年第1期58-64,共7页Ecology and Environmnet

基　　金：中国科学院知识创新工程项目(KZCX-SW-01-01B-05KSCX2-SW-133)

摘　　要：采用静态箱-气相色谱法对典型华南农林复合生态系统早稻田CH4和N2O排放进行田间原位测定,探讨早稻田两种温室气体的排放规律。结果表明,有植株参与稻田在水稻生长季节中CH4排放昼夜变化表现为双峰模态,收割后为三峰模态,CH4排放昼夜变化幅度比无植株参与稻田大。在测定期内有植株参与稻田CH4昼夜平均排放通量大小依次为:成熟期(1.96±0.33)>孕穗期(0.13±0.01)>收割后(-0.01±0.02)(mg.m-2.h-1)。有植株参与稻田在孕穗期CH4昼夜平均排放通量显著高于无植株参与稻田(P<0.01)。在测定期内有、无植株参与稻田CH4平均排放通量分别为0.85±0.28、0.14±0.09 mg.m-2.h-1。有、无植株参与稻田N2O昼夜平均排放通量没有显著差异。在测定期内有、无植株参与稻田N2O平均排放通量分别为118.07±50.97、15.65±21.56μg.m-2.h-1。CH4和N2O的排放无论是昼夜变化还是季节变化都与温度没有明显相关关系,其排放受稻田水分和养分状况的影响。水稻作物对CH4排放影响较大,对N2O排放影响不明显。A field experiment was conducted to evaluate CH4 and N2O emissions from paddy field of agroforestry ecosystem in hilly area of South China with closed static chamber and a modified gas chromatograph （HP5890Ⅱ ） in situ in the first crop season. In this paper, gas samples were taken simultaneously from rice-involved and rice uninvolved plots. Results showed that the diurnal change of CH4 flux had two peak values in a day in the crop growing season and three peak values at off-crop stage. The diurnal change of CH4 flux from rice-involved plot was bigger than that of rice uninvolved plot. The diurnal mean CH4 flux from rice-involved plot was in the order： ripening stage （ 1.96±0.33 ） 〉booting stage （0.13±0.01）〉off-crop stage （ -0.01±0.02 ） （ m g· m^-2·h^-1 ）. The diurnal mean CH4 flux from rice-involved plot was significantly higher than that of rice uninvolved plot in the booting stage （P〈0.01）. During the measuring time, the mean CH4 flux from rice-involved plot and rice uninvolved plot was 0.85±0.28 mg·m^-2·h^-1 and 0.14±0.09 mg· m^-2· h^-1, respectively. The diurnal mean N2O flux from rice-involved plot showed no significantly diffcrenec from that of rice uninvolved plot. During the measuring time, the mean N2O flux from rice-involved plot and rice uninvolved plot was 118.07±50.97 μg·m^-2·h^-1 and 15.65±21.56 μg2m^-2·h^-1, respectively. It showed no significant correlation between CH4 and N2O fluxes and temperature. The fluxes of CH4 and N2O were affected by soil moisture and fertilizer. Rice plants played a key role on the CH4 emission from paddy field but not on the N2O emission.

关 键 词：农林复合生态系统 稻田 CH4 N2O 

分 类 号：X144[环境科学与工程—环境科学]