Carbon stocks in aboveground biomass of eight-year-old Pinus and Eucalyptus species planted in sub-humid grassland soils

Abstract

ABSTRACT There is a considerable body of knowledge on aboveground biomass in different planted trees species, but there has been less investigation of the influence of soil types and drainage on tree biomass accumulation. Thus, by taking tree species and soil types into account, the aim of this paper was to quantify the carbon (C) stocks of the aboveground biomass in the Weatherley catchment, situated in the north-eastern part of the Eastern Cape Province of South Africa. Eight years after the establishment of trees in native grassland soils, litter mass and the C and nitrogen (N) content thereof as well as the tree mass and the C content thereof were measured at 27 sites. The C stocks in the aboveground biomass differed between sites, tree species and soil types. Biomass C stock ranged from 4.8 Mg C ha−1 for the grass to 24.7 and 40.3 Mg C ha−1, for Pinus elliottii and Pinus patula, respectively, and 49.1 Mg C ha−1 for Eucalyptus nitens. Poorly and freely drained soils (35.6 and 34.1 Mg C ha−1, respectively) had lower biomass C stocks than the moderately drained soils (40.3 Mg C ha−1). Tree species and soil types were therefore the main factors that determined C sequestration rate.