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

Abstract

[1] Measurements of soil CO 2 efflux, litter production, and the surface litter pool biomass were made over a 1 year period in a tropical transitional forest near Sinop, Mato Grosso, Brazil with the aim of quantifying the seasonal variation in soil respiration and litter decomposition and the annual contribution of litter decomposition to soil CO 2 efflux. Average annual soil CO 2 efflux (±95% confidence interval (CI)) was 7.91 ± 1.16 g C m À2 d À1 . Soil CO 2 efflux was highest during the November-February wet season (9.15 ± 0.90 g C m À2 d À1 ) and lowest during the May-September dry season (6.19 ± 1.40 g C m À2 d À1 ), and over 60% of the variation in seasonal soil CO 2 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 dry seasons (0.66 ± 0.08 and 1.65 ± 0.10 g C m À2 d À1 , 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 À1

Litterfall production in intact and selectively logged forests in southern of Amazonia as a function of basal area of vegetation and plant density

“…A maior produção de serrapilheira nessas regiões pode estar associada ao regime de chuva local e, principalmente, aos impactos gerados pela deficiência hídrica Valentini et al 2008). Contudo, estudos ecofisiológicos identificaram que as florestas que se desenvolvem em regiões com sazonalidade climática acentuada, apresentam mecanismos para minimizar os impactos do déficit hídrico (e.g.…”

Arbuscular mycorrhizal mycelial respiration in a moist tropical forest

“…3b). The major seasonal constraints on microbial activity are litterfall and precipitation (Vasconcelos et al, 2004;Valentini et al, 2008), so we propose that the seasonality of soil CO 2 efflux in our semi-evergreen moist tropical forest was a consequence of the decomposition of litter leachate following rainfall, seasonal priming of soil C stimulated by input of labile litter C (Sayer et al, 2007), and rewetting effects (Jarvis et al, 2007).…”

Soil CO2 Efflux Measurements by Alkali Absorption and Infrared Gas Analyzer in the Brazilian Semiarid Region

“…However, measurements in forest, Cerrado, and agricultural areas in other Brazilian regions (Sotta et al, 2004;Valentini et al, 2008;Panosso et al, 2009;Pinto-Junior et al, 2009;Zanchi et al, 2012) (Moitinho et al, 2013); all other maximum values were two to five times higher than the minimum values. These findings suggest that the IRGA methodology has higher sensitivity in detecting ECO 2 differences than the AA methodology.…”

“…Several studies have quantified ECO 2 in specific areas in Brazil (Valentini et al, 2008;Panosso et al, 2009;Souto et al, 2009;Araujo et al, 2011;Ivo and Salcedo, 2012;Correia et al, 2015;Holanda et al, 2015) and in other countries (Deng et al, 2012;Chen et al, 2014;Zheng et al, 2014). These studies used different methodologies to quantify ECO 2 , the most common ones being CO 2 absorption in an alkaline solution (AA), in general 0.5 or 1.0 mol L -1 KOH or NaOH (Souto et al, 2009;Araujo et al, 2011;Correia et al, 2015).…”

“…These studies used different methodologies to quantify ECO 2 , the most common ones being CO 2 absorption in an alkaline solution (AA), in general 0.5 or 1.0 mol L -1 KOH or NaOH (Souto et al, 2009;Araujo et al, 2011;Correia et al, 2015). Other studies adopt dynamic measurement made with an infrared gas analyzer (Valentini et al, 2008;Panosso et al, 2009). These methodologies differ in precision, applicability, and spatial and temporal resolution (Janssens et al, 2000;Yim et al, 2002).…”