Methanotrophs and CH₄ sink: Effect of human activity and ecological perturbations

Methane (CH₄) is the most potent greenhouse gas and contributes significantly in global warming phenomenon. The lifetime of this gas in the atmosphere is about 8 to 12 years. Therefore, its continuous increasing concentration in the atmosphere due to imbalances between genesis and oxidation is a great cause of concern. Methanotrophs has been recognized as the only efficient bioagent responsible for CH₄ uptake at higher rate in upland arable soil. A number of environmental and anthropogenic perturbations affect the methanotrophs community composition and CH₄ sink phenomenon. The change in landuse patterns influences the methanotrophic diversity in the soil of different ecosystems. The changes in methanotrophic community composition may also have significant consequences for their potential capacity to respond to future changes in climatic conditions and the potential to restore CH₄ sink after degradation. Therefore, it is important to understand the effects of land degradation on soil methanotrophic community composition. However, the information related to this emerging environmental issue is scare. Therefore, in this article an attempt has been made to review on CH₄ consumption and methanotrophs numbers as affected by the diverse environmental and man-made perturbations.