CO2 and Methane Fluxes by Ecosystem Type and the Long-Term Feedback Relationship with the Atmosphere: Methane Fluxes and Control

北极系统科学（ARCSS）陆地/大气/冰相互作用（LAII）通量研究的CH4组成部分的目标是：1)产生区域CH4通量估算；2)进行实地实验，阐明冻土带环境对CH4和CO2排放的控制和反馈。区域通量估计将利用覆盖一系列地理省份的样带沿线永久站点的时间序列室测量CH4通量。测量的地点和时间将与大气二氧化碳研究、植被测绘研究和土壤化学研究相协调。野外实验将包括土壤温度和地下水位的操纵，在一系列温度和水分含量下的罐子和岩心实验，以及一系列同位素标记实验。这些实验将提供有关CH4氧化对温度和湿度变化的信息，以及最近固定碳在CH4和CO2排放中的作用。这些实验将与其他LAII-Flux研究人员合作进行。

The goals of the CH4 component of the Arctic System Science (ARCSS) Land/Atmosphere/Ice Interactions (LAII) Flux Study are to: 1) produce regional CH4 flux estimates, and 2) perform field experiments that will elucidate the controls and feedback on CH4 and CO2 emission from tundra environments. The region flux estimates will be made using time series chamber measurements of CH4 flux at permanent sites along a transect covering a range of physiographic provinces. The locations and times of measurements will be coordinated with atmospheric CO2 studies of, with vegetation mapping studies, and with soil chemistry studies. The field experiments will involve manipulations of soil temperature and water table level, jar and core experiments at a range of temperatures and moisture contents, and a series of isotope labelling experiments. The experiments will provide information on CH4 oxidation to temperature and moisture changes, and the role of recently-fixed carbon in CH4 and CO2 emissions. These experiments will be performed in collaboration with other LAII-Flux investigators.