11:15 AM - 11:30 AM
[AAS04-09] Methane uptake in global forest and grassland soils over the period 1981-2010
Keywords:methane uptake, climate change
Methane (CH4) is one of the most potent greenhouse gases. It is generally recognized that forest and grassland soils consume the atmospheric CH4, but the quantities and spatiotemporal changes in the CH4 uptake remain largely uncertain as far as global forest and grassland are concerned. Here, we estimated CH4 uptake in global forest and grassland soils over the period of 1981-2010 using an empirical model developed in this study. We show that the mean values of CH4 uptake were 9.16 (±3.83) Tg yr-1 in forest soils, and 3.76 (±1.42) Tg yr-1 in grassland soils, respectively. Tropical forest and grassland soils are the largest CH4 sink, contributing 58% to the total sink. Methane uptake in cool temperate dry and warm temperate dry soils, and in polar/boreal grassland soils showed a significant increase, while a significant decrease was found in tropical dry grassland soils over the thirty years. Our findings highlight the quantities of CH4 uptake in global forest and grassland soils, and underline the spatiotemporal changes in CH4 uptake over the thirty years so as to better understand the impact of climate change on soil CH4 sink.