Effects of ant nests on soil CH4 emissions from Syzygium oblatum communities of a secondary tropical for-est
Exploring the effects of ant nests on soil CH4 emissions in the secondary tropical forests is of great scien-tific significance to understand the contribution of soil faunal activities to greenhouse gas emissions.With static chamber-gas chromatography method,we measured the dry-wet seasonal dynamics of CH4 emissions from ant nests and control soils in the secondary forest of Syzygium oblatum communities in Xishuangbanna.We also examined the linkages of ant-mediated changes in functional microbial diversity and soil physicochemical properties with CH4 emissions.The results showed that:1)Ant nests significantly accelerated soil CH4 emissions,with average CH4 emissions in the ant nests being 2.6-fold of that in the control soils.2)The CH4 emissions had significant dry-wet seasonal variations,which was a carbon sink in the dry seasons(from -0.29±0.03 to -0.53±0.02 μg·m-2·h-1)and a carbon source in the wet seasons(from 0.098±0.02 to 0.041±0.009 µg·m-2·h-1).The CH4 emissions were significantly higher in ant nests than in control soils.The CH4 emissions from the ant nests had smaller dry-wet seasonal variation(from-0.38±0.01 to 0.12±0.02 μg·m-2·h-1)than those in the control soils(from-0.65± 0.04 to 0.058±0.006 µg·m-2·h-1).3)Ant nests significantly increased the values(6.2％-37.8％)of soil methanogen diversity(i.e.,Ace and Shannon indices),temperature and humidity,carbon pools(i.e.,total,easi-ly oxidizable,and microbial carbon),and nitrogen pools(i.e.,total,hydrolyzed,ammonium,and microbial bio-mass nitrogen),but decreased the diversity(i.e.,Ace and Chao1 indices)of methane-oxidizing bacteria by 21.9％-23.8％.4)Results of the structural equation modeling showed that CH4 emissions were promoted by soil methanogen diversity,temperature and humidity,and C and N pools,but inhibited by soil methane-oxidizing bacterial diversity.The explained extents of soil temperature,humidity,carbon pool,nitrogen pool,methanogen diversity,and methane-oxidizing bacterial diversity for the CH4 emission changes were 6.9％,21.6％,18.4％,15.2％,14.0％,and 10.8％,respectively.Therefore,ant nests regulated soil CH4 emission dynamics through altering soil functional bacterial diver-sities,micro-habitat,and carbon and nitrogen pools in the secondary tropical forests.
ant nestCH4 emissionmethanogenmethane-oxidizing bacteriatropical forestXishuangbanna
国家科技期刊平台
NSTL
万方数据
