EKOSISTEM SAWAH

22
Microbial turnover of methane and transport pathways of gases in wetlands.
(Sumber: http://www.ibp.ethz.ch/research/environmentalmicrobiology/research/Wetlands)
In-situ quantification of soil microbial processes controlling methane emissions
from rice paddy soils.
Rice paddy soil is among the most important anthropogenic sources of methane.
Methane is produced anaerobically after the flooding of rice fields, either from
acetate or hydrogen/carbon dioxide as substrate. In contrast, methanotrophic
microorganisms oxidize methane to carbon dioxide in the presence of molecular
oxygen in the root zone or at the air/water interface, thus reducing the overall
methane emissions to the atmosphere. Quantification of methane turnover in soil
slurry incubation under laboratory conditions is potentially biased. Therefore, the
main aim of this project is to design a novel tool for the quantification of methane
production and consumption in the rice root zone. Specifically, we aim at the
development of an in situ quantification method which allows us to assess the effect
of methane turnover in the root zone on net methane emissions. The quantification
concept includes the combination of push-pull tests (PPT), specific inhibitors, stable
isotope fractionation and flux measurements. In a further step, we will apply this
technique to assess methane turnover and emissions over a whole growth period of
rice plants, and to investigate if changes are also reflected in the abundance of
methanogenic/ methanotrophic organisms.