On an area covered by dense stands of Colophospermum mopane with little or no grass cover, ten sites were randomly selected. In the centre of each site, a core (monolith) of soil (2.0 m x 0.5 m x 1.0 m deep)was excavated and removed in 5 layers of 200 min. Roots were washed from the soil and sorted into classes (0-1.0 mm, > 1.0-5.0 mm, > 5.0-10.0 mm, > 10.0 mm), dried and weighed. The canopy dimensions of C. mopane around each excavation were measured and the leaf dry mass estimated using a regression equation which relates spatial canopy volume to leaf dry mass. Total root biomass ranged from 9 760 kg ha-1 to 29 790 kg ha-1 (mean: 17 354 kg ha-1). Of these a mean of 19% were in the 0-1.0 mm diameter class, and 20.3%, 16.2% and 44.5% in the > 1.0-5.0 mm, > 5.0-10.0 mm and > 10 mm diameter classes respectively. A mean of 66.1% of all fine roots (< 5.0 mm) was found within the first 400 mm of the soil. The coarse roots (> 5.0 mm) were virtually absent within the 0-200 mm soil layer, with the highest concentration between 200-600 mm. Leaf biomass was found to be significantly lower than the root biomass.
Smit, G. N., & Rethman, N. F. G. (1998). Root biomass, depth distribution and relations with leaf biomass of Colophospermum mopane. South African Journal of Botany, 64(1), 38–43. https://doi.org/10.1016/S0254-6299(15)30825-5