Driving factors of tree biomass and soil carbon pool in xerophytic forests of northeastern Argentina

SIONE, SILVANA MARÍA JOSÉ; WILSON, MARCELO GERMÁN; LEDESMA, SILVIA GABRIELA; GABIOUD, EMMANUEL ADRIÁN; OSZUST, JOSÉ DANIEL; ROSENBERGER, LEANDRO JAVIER

Ecological Processes

Springer

Lugar: London; Año: 2023 vol. 12

AbstractBackground The conversion of forests into agricultural lands can be a threat because the forests carbon stored couldbe a source of emissions. The capacity to improve the predictions on the consequences of land use change dependson the identification of factors that influence carbon pools. We investigated the key driving factors of tree biomassand soil carbon pools in xerophytic forests in northeastern Argentina. Based on analyses of forest structure variablesand abiotic factors (topography and soil properties) from 18 mature forests, we evaluated carbon pools using uni-and multivariate (redundancy analysis) methods.Results The total carbon pool was estimated at 102.4 ± 24.0 Mg ha−1. Soil organic carbon storage is the single larg-est carbon pool relative to tree biomass, representing 73.1% of total carbon. Tree canopy cover and basal area werepositively correlated with biomass carbon pool (r = 0.77 and r = 0.73, p < 0.001, respectively), proving to be significantdrivers of carbon storage in this compartment. Slope, soil clay content and cation-exchange capacity had a betterexplanation for the variability in soil carbon pools, and all showed significant positive correlations with soil carbonpools (r = 0.64, 0.60 and 0.50; p < 0.05, respectively). The vertisols showed a 27.8% higher soil carbon stock than alfisols.Conclusions The relevance of our study stems from a dearth of information on carbon pools and their driversin xerophytic forests, and in particular, the importance of this ecosystems’ type for Argentina, because they cover81.9% of native forest area. Basal area and tree canopy cover exert a strong effect on the carbon pool in tree biomassbut not in the soil. The results suggests that there is a potentially major SOC accumulation in forests located in slightlysloping areas and soils with higher topsoil clay content, such as vertisols. This could provide an important referencefor implementing forestry carbon sink projects.Keywords Carbon pool, Forest biomass, Soil parameters, Ecosystem services