火干扰对小兴安岭草丛、灌丛沼泽温室气体短期排放的影响  

Short-term effects of fire disturbance on greanhouse gases emission from hassock and shrubs forested wetland in Lesser Xing′an Mountains,Northeast China

作　　者：顾韩[1,2] 牟长城[1] 张博文 于丽丽[4] 

机构地区：[1]东北林业大学林学院,哈尔滨150040 [2]黑龙江科技学院,哈尔滨150027 [3]佳木斯市环境科学院,佳木斯150040 [4]内蒙古民族大学,通辽028000

出　　处：《生态学报》2012年第19期6044-6055,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30670349)

摘　　要：利用静态箱-气相色谱法,研究了火烧干扰对小兴安岭草丛、灌丛沼泽生长季CH4、CO2、N2O排放的季节变化及影响因子结果表明:火干扰使草丛、灌丛沼泽生长季的平均气温和各层土壤温度提高0.1—2.0℃,水位平均下降2.7 cm。火干扰使草丛、灌丛沼泽样地CH4排放通量提高了56%、524.9%,CO2排放通量分别下降了57.3%、14.5%,N2O排放通量分别下降27.1%,64.9%。火烧前后草丛沼泽CH4、N2O与灌丛沼泽CO2排放通量季节性规律未发生变化。火干扰改变了草丛沼泽生长季CO2、灌丛沼泽N2O排放通量的季节性变化规律。草丛沼泽对照样地CH4排放通量与5 cm土壤温度存在显著相关性,草丛沼泽CH4排放通量与水位相关性不显著。灌丛沼泽CH4排放通量与各层土壤温度及水位均无显著相关性。草丛、灌丛沼泽对照样地土壤CO2排放通量与0—15 cm土壤温度呈显著或极显著正相关,火烧样地与0—30 cm土壤温度呈显著或极显著正相关。草丛、灌丛沼泽对照、火烧样地土壤CO2排放通量与水位极显著负相关。火干扰使草丛、灌丛沼泽CH4排放源的强度增强,CO2、N2O的排放消弱,全球温室潜势下降约为23.3%。火干扰能够减少草丛、灌丛沼泽温室气体排放。Wetlands are important sources and sinks of greenhouse gases. Fire is an important disturbance factor in forested wetlands, the forestry of fire disturbance were 1% per year on average in the global. Fire-related disturbance in forests are more frequent in mid-to high latitudes than elsewhere. In the present study, two kinds of forested wetlands ; Carex schmidtii wetland and Betula ovalifolia-Carex schmidtii shrub wetland, were studied to reveal the emission variation of CH4, CO2 , and N20 under fire disturbance during the growing season. The study area is located in the Lesser Xing＇an Mountains. We used a static opaque chamber and gas chromatography methods, and we monitored related environmental factors. The results were as follows ： disturbance by fire increased air and soil temperature by 0.1--2.0℃, and lowered the water table by an average of 2.7 cm. Burning increased CH4 emissions from marsh and shrub wetlands by 56% and 524.9% , respectively. Burning decreased the CO2 and N20 emissions by 27. 1% and 64.9% respectively from the marsh, and 27. 1% and 64. 9% from the shrub wetland. Burning also changed the marsh wetland CO2 and shrub wetland N20 flux patterns in the growing season, but no marked variations were detected in the marsh wetland CH4 and N20, and in the shrub wetland COz flux patterns. The CH4 emissions and the seasonal change pattern were affected by fire disturbance. Before and after the fire disturbance, CH4 emission flux remained unchanged during the growing season. The cn4 was absorbed weakly by the wetland soil in spring and emitted in summer and autumn. The CH4 emission flux in summer was less than that in autumn. However, the CO2 and N20 emission fluxes had changed. At the unburned site, the CO2 flux had a seasonal variation where summer flux 〉 spring 〉 autumn; under fire disturbance, the CO2 flux in summer 〉 autumn〉 spring. The N20 flux varied in the order of spring 〉 summer 〉 autumn under no fire disturbance, but under slight fire disturbance, the order was spring 〉 s

关 键 词：小兴安岭 草丛森林沼泽、灌丛森林沼泽 温室气体排放 火干扰 

分 类 号：X16[环境科学与工程—环境科学]