【摘要】 高寒湿地是大气中甲烷（CH₄）重要的排放源,气温升高和水位波动会对脆弱的高寒湿地CH₄排放产生影响。为了解高寒湿地不同区域CH₄通量特征以及差异,以位于青藏高原中部的隆宝滩湿地为研究对象,分别在湿地中的湿地区域（WA）、过渡带区域（TA）、平坦地区域（FA）,使用便携式温室气体分析仪原位观测CH₄通量的变化,分析和确定高寒湿地CH₄排放的时空异质性及其影响因素。结果表明,WA和TA是CH₄排放源,在生长旺季（7-9月）CH₄通量的日变化特征为单峰型,峰值出现在午后（14:00-15:00）,FA表现为CH₄的"汇",其日变化特征较不明显。3个区域的CH₄通量有显著的季节变化差异（P<0.05）,WA、TA和FA的CH₄通量峰值分别出现在7月、8月和8月,峰值分别为25.46、25.13、-0.42 nmol?m^-2?s^-1。测定期间,WA、TA和FA的CH₄通量均值分别为905.75、581.58、-9.02μg?m^-2?h^-1,差异显著（P<0.01）,其变异系数分别为63.5%、76.3%、85.9%。Pearson相关分析表明,3个区域的CH₄通量均与土壤温度呈极显著相关（P<0.01）,表明土壤温度是CH₄通量的重要影响因素。WA和FA的CH₄通量与土壤湿度呈显著相关（P<0.05）,TA的CH₄通量与土壤湿度无显著相关性（P>0.05）,但是TA不同土层Q10值均大于WA,表明TA的CH₄通量对土壤温度的变化比WA更敏感。更多还原

【Abstract】 Alpine wetlands are important sources of atmospheric methane（CH₄）. Temperature increase and fluctuations in water levels will affect CH₄ emissions from fragile alpine wetlands. In order to understand the characteristics and differences of CH₄ flux in different areas of alpine wetland, this study takes the Longbaotan wetland in the middle of the Qinghai-Tibet Plateau as a research object, using ultra-portable greenhouse gas analyzer to observe the variations of CH₄ flux in wetland area（WA）, transition area（TA）and flat area（FA） respectively, analyze and determine the spatial and temporal heterogeneity of CH₄ emissions in alpine wetlands and its influencing factors. The results showed that WA and TA were CH₄ emission sources. The diurnal variation of CH₄ flux was a monopeak curve at WA and TA sites during the growing season（July–September） and the peak appeared in the afternoon（14:00–15:00）, whereas there was no significant diurnal variation at FA. The CH₄ fluxes for the three areas had significant seasonal variation（P<0.05）, and the CH₄ flux peaks at WA, TA, and FA appeared in July, August and August, with peak values of 25.46, 25.13, and-0.42 nmol·m^-2·s^-1, respectively. During the measurement period, the mean CH₄ fluxes of WA, TA and FA were 905.75, 581.58 and-9.02 μg·m^-2·h^-1, respectively. The CH₄ flux differences between WA, TA and FA were significant（P<0.01）, and the coefficients of variation were 63.5%, 76.3% and 85.9%, respectively. Pearson correlation analysis showed that the CH₄ fluxes at the three areas were significantly correlated with soil temperature（P<0.01）, indicating that soil temperature was an important factor affecting CH₄ fluxes. The CH₄ fluxes of WA and FA were significantly correlated with soil moisture（P<0.05）, while the CH₄ fluxes of TA had no significant correlation with soil moisture（P>0.05）. However, the Q10 values of different soil layers of TA were greater than those of WA, indicating that the CH₄ flux of TA was more sensitive to soil temperature than that of WA.更多还原