Temperature Dependent Decline in Soil Methane Oxidizing Bacterial Population in Tropical Dry Deciduous Forest Ecosystems

Culturable methanotrophic bacteria (CMB) were studied in the soils of forest and savanna of tropical dry deciduous forest ecosystems employing most probable number (MPN) technique. The spatiotemporal study was conducted at the six sites differing in the soil physicochemical properties and vegetational cover. CMB population was high in the moist sites compared to the dry sites and in sub soil below 10 cm depth. The top soil population ranged between 7.0 × 10 4 to 7.1 × 10 6 g -1 dry soil. The population declined exponentially with depth. In temporal study at bimonthly interval for two consecutive years, high CMB population was in winter that declined 10 20 fold in rain. The CMB population variation was explained solely by temperature (59%), temperature and soil nitrate (76%), and temperature soil nitrate and moisture (77.4%) in the step wise regression analysis. Index Terms Dry tropical forest, Methanotrophs; MOB, NH4 + -N; NO3 -N; Soil moisture; spatiotemporal variation, ————————————————————