In Cyperus marsh, Spartina marsh and Kandelia forest, the soil surface covered by chambers was free of vegetation or benthic burrows, while in Sonneratia forest, short slim aboveground pneumatophores of mature Sonneratia trees occupied the soil surface at a density of 235.2 ± 3.2 per square meter. Therefore, two or three pneumatophores were covered under each chamber in Sonneratia forest. Before sampling, the open end of the chamber was gently inserted 2 cminto the soil, and a thermometer was inserted next to the chamber 5 cm into the soil to record soil temperature
(Liu et al., 2006). The devices were stabilized for 30 s before sealing the sampling hole with a rubber and silicone putty. Pilot experiments indicated that the concentration of greenhouse gases in the static chamber increased linearly within about the first 50 min. Therefore, 5ml gas samples were collected from each chamber at intervals of 15 min. The gas
samples were then transported immediately to dark airtight containers and analyzed within 12 h by a gas chromatography (GC) technique to determine the soil–atmosphere fluxes of three greenhouse gases.
In Cyperus marsh, Spartina marsh and Kandelia forest, the soil surface covered by chambers was free of vegetation or benthic burrows, while in Sonneratia forest, short slim aboveground pneumatophores of mature Sonneratia trees occupied the soil surface at a density of 235.2 ± 3.2 per square meter. Therefore, two or three pneumatophores were covered under each chamber in Sonneratia forest. Before sampling, the open end of the chamber was gently inserted 2 cminto the soil, and a thermometer was inserted next to the chamber 5 cm into the soil to record soil temperature(Liu et al., 2006). The devices were stabilized for 30 s before sealing the sampling hole with a rubber and silicone putty. Pilot experiments indicated that the concentration of greenhouse gases in the static chamber increased linearly within about the first 50 min. Therefore, 5ml gas samples were collected from each chamber at intervals of 15 min. The gassamples were then transported immediately to dark airtight containers and analyzed within 12 h by a gas chromatography (GC) technique to determine the soil–atmosphere fluxes of three greenhouse gases.
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