Fluxes of CH4 and N2O from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China.
CH4 and N2O fluxes from soil under a tropical seasonal rain forest in Xishuangbanna, Southwest China were measured for one year using closed static chamber technique and gas chromatography method. Three treatments were set in the studied field: (A) litter-free, (B) with litter, and (C) with litter and seedling. The results showed that the soil in our study was a sink of atmospheric CH4 and source of atmospheric N2O. The observed mean CH4 fluxes from treatments A, B, and C were -50.0 +/- 4.0, -35.9 +/- 2.8, -31.6 +/- 2.8 microgC/(m2 x h), respectively, and calculated annual fluxes in 2003 were -4.1, -3.1, and -2.9 kgC/hm2, respectively. The observed mean N2O fluxes from treatments A, B, and C were 30.9 +/- 3.1, 28.2 +/- 3.5, 50.2+/-3.7 microgN/(m2 x h), respectively, and calculated annual fluxes in 2003 were 2.8, 2.6, and 3.7 kgN/hm2, respectively. Seasonal variations in CH4 and N2O fluxes were significant among all the three treatments. The presence of litter decreased CH4 uptake during wet season (P < 0.05), but not during dry season. There was a similar increase in seedlings-mediated N2O emissions during wet and dry seasons, indicating that seedlings increased N2O emission in both seasons. A strong positive relationship existed between CH4 fluxes and soil moisture for all the three treatments, and weak relationship between CH4 fluxes and soil temperature for treatment B and treatment C. The N2O fluxes correlated with soil temperature for all the three treatments.
Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China. yanyp@xtbg.org.cn
Yuping
Y
Yan
Liqing
L
Sha
Min
M
Cao
Zheng
Z
Zheng
Jianwei
J
Tang
Yinghong
Y
Wang
Yiping
Y
Zhang
Rui
R
Wang
Guangren
G
Liu
Yuesi
Y
Wang
Yang
Y
Sun
D000393:Air Pollutants / Q000032:analysis*; D018533:Biomass; D002681:China; D004784:Environmental Monitoring; D008697:Methane / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis*; D011891:Rain; D012621:Seasons; D036226:Seedlings / Q000254:growth & development; D012989:Soil Pollutants / Q000032:analysis*; D013696:Temperature; D014197:Trees; D014329:Tropical Climate; D014867:Water / Q000032:analysis
D000393:Air Pollutants; D012989:Soil Pollutants; D014867:Water; D009609:Nitrous Oxide; D008697:Methane