The feasibility of restoring subtropical thicket using carbon markets is largely a function of its carbon sequestration potential. We measured below-ground carbon stocks and analysed soil properties in intact, degraded and old agricultural landscapes in Baviaans Spekboom Thicket - a highly degraded thicket type earmarked for restoration. Soil and root carbon stocks to a depth of 110 cm in intact thicket were 93 - 7 (SE) t ha-1 and 11 -2 t ha-1, respectively. Degraded thicket had approximately one-third of the soil (31 - 2 t ha-1) and one-quarter of the root (2.7 - 0.3 t ha-1) carbon of intact thicket. Old agricultural lands had approximately half of the soil (42 - 4 t ha-1) and quarter of the root (2.6 - 0.3 t ha-1) carbon of intact thicket. Soil carbon stocks in topsoil were constrained at low concentrations of extractable K (<0.5 mmolc kg-1), Mg (<1 mmolc kg-1), Ca (<12 mmolc kg-1) and extractable P (<40 mg kg-1), suggesting that carbon sequestration will be strongly influenced by soil nutrient content. Restoration of Baviaans Spekboom Thicket stands to sequester 70 - 8 t ha-1 of below-ground carbon - an amount rivalling sequestration potentials in degraded mesic forests.
Journal articles from the Grassland Society of Southern Africa (GSSA) African Journal of Range and Forage Science as well as related articles and reports from throughout the southern African region.