Effect Of Precipitation Change On Methane Oxidation Of Subtropical Chinese Fir Plantation In China

Methane oxidation rates were measured from Sptemper2010to Sptemper2011in an Cunninghamia Lanceolata plantation of Wanmulin Natural Reserve, Fujian Province, China. Our objective was to investigate the effects of precipitation change on methane oxidation rate and physical properties of the soil to better understand change patterns and mechanisms. The chief results are showed as follows:The oxidation rates were higher in Summer-Autumn and lower in Winter-Spring, maximum value appearing Augest. The methane annual flux in the-100%,-60%,-20%, control,+100%samples were4.10kg-hm-2·y-1,3.58kg·hm-2·y-1,2.96kg·hm-2·y-1,2.48kg·hm-2·y-1,2.46kg·hm-2·y-1,respectively.The casuse of different methane oxidation patterns in the five simulated rainfall conditions rates maybe like this:1) Reduction in precipitation decreace the soil water content, which improve the soil aeration; however, double precipitation had little effect on the soil aeration.2) The change of methane oxidation ablity of0-5cm soil horizons were different in the samples, which may cause the methane oxidation patterns difference in the samples,3) The ablity is positively correlated with ammonium nitrogen, which maybe the chemical reason. There were short methane emission in the cold spell, which had the same daily variation.