Zhuang Q, Melillo J M, McGuire A D, Kicklighter D W, Prinn R G, Steudler P A, Felzer B S, Hu S
The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, USA.
Ecol Appl. 2007 Jan;17(1):203-12. doi: 10.1890/1051-0761(2007)017[0203:neocac]2.0.co;2.
We used a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to study the net methane (CH4) fluxes between Alaskan ecosystems and the atmosphere. We estimated that the current net emissions of CH4 (emissions minus consumption) from Alaskan soils are approximately 3 Tg CH4/yr. Wet tundra ecosystems are responsible for 75% of the region's net emissions, while dry tundra and upland boreal forests are responsible for 50% and 45% of total consumption over the region, respectively. In response to climate change over the 21st century, our simulations indicated that CH4 emissions from wet soils would be enhanced more than consumption by dry soils of tundra and boreal forests. As a consequence, we projected that net CH4 emissions will almost double by the end of the century in response to high-latitude warming and associated climate changes. When we placed these CH4 emissions in the context of the projected carbon budget (carbon dioxide [CO2] and CH4) for Alaska at the end of the 21st century, we estimated that Alaska will be a net source of greenhouse gases to the atmosphere of 69 Tg CO2 equivalents/yr, that is, a balance between net methane emissions of 131 Tg CO2 equivalents/yr and carbon sequestration of 17 Tg C/yr (62 Tg CO2 equivalents/yr).
我们使用了一个生物地球化学模型——陆地生态系统模型（TEM），来研究阿拉斯加生态系统与大气之间的甲烷（CH₄）净通量。我们估计，目前阿拉斯加土壤的CH₄净排放量（排放量减去消耗量）约为每年3太克CH₄。湿苔原生态系统占该地区净排放量的75%，而干苔原和山地北方森林分别占该地区总消耗量的50%和45%。针对21世纪的气候变化，我们的模拟结果表明，湿土的CH₄排放量增加幅度将超过苔原和北方森林干土的消耗量增加幅度。因此，我们预计，由于高纬度地区变暖及相关气候变化，到本世纪末CH₄净排放量将几乎翻倍。当我们将这些CH₄排放情况置于21世纪末阿拉斯加预计的碳预算（二氧化碳[CO₂]和CH₄）背景下时，我们估计阿拉斯加将成为大气中温室气体的净排放源，每年排放69太克二氧化碳当量，即每年131太克二氧化碳当量的甲烷净排放量与每年17太克碳（62太克二氧化碳当量）的碳固存之间的平衡。
