Soil respiration and aboveground litter dynamics of a tropical transitional forest in northwest Mato Grosso, Brazil

1.16 g C m . Soil CO2 efflux was highest during the November – February wet -2 d -1 season (9.15 ± 0.90 g C m ) and lowest during the May – September dry season -2 d -1 (6.19 ± 1.40 g C m ), and over 60% of the variation in seasonal soil CO2 efflux was explained by seasonal variations in soil temperature and moisture. Mass balance estimates of mean (±95% CI) decomposition rates were statistically different between the wet and -2 d -1 dry seasons (0.66 ± 0.08 and 1.65 ± 0.10 g C m , respectively), and overall, decomposition of leaf litter comprised 16% of the average annual soil respiration. Leaf litter production was higher during the dry season, and mean (±95% CI) leaf litter fall (5.6 ± 1.7 Mg ha -1 ) comprised 73% of the total litter fall (7.8 ± 2.3 Mg ha -1 ). Average (±95% CI) annual litter pool biomass was estimated to be 5.5 ± 0.3 Mg ha -1 , which was similar to the measured pool size (5.7 ± 2.2 Mg ha -1 ). Overall, seasonal variations in environmental variables, specifically water availability (soil moisture and rainfall), had a profound influence on litter production, soil respiration, and surface litter decomposition.