Variation in carbon stock along a slope gradient for a highland bamboo (Oldeania alpina (K.Schum.) Stapleton) plantation: A case study from Banja District, Awi Zone, northwestern Ethiopia

Abstract

We attempted to estimate the variation in the carbon stock of highland bamboo ( Oldeania alpina ) plantations across different slope angles in the Banja District of Awi Zone, northwestern Ethiopia. Four plots (10 m x 10 m) were established at each of three slope gradients (0–9%, 10–15% and >16%). In total, 12 main plots were used for the biomass sampling. Within each main plot, five sub-plots (1 m x 1 m) were located at the corners and centre, and soils were sampled at depths of 0–36 cm and 37–72 cm. A total of 60 sub-plots were used for the soil and litter sampling. Three culms were randomly selected by lottery method from each of three age classes (1–2 years, 3–4 years, and >5 years) in each of the 12 main plots to derive the biomass estimates. Biomass was derived using allometric equations whereas the soil carbon stock was estimated using the Walkley-Black method. The average culm density and diameter at breast height (DBH) of the culms in the study area were 21,658 ± 10,447 plants ha⁻¹ and 5.71 ± 0.69 cm, respectively. The mean total soil organic content, and the aboveground, belowground and litter carbon densities were 299 ± 50.7 t ha⁻¹, 99.5 ± 33.8 t ha⁻¹, 24.9 ± 5.35 t ha⁻¹, and 7.19 ± 1.72 t C ha⁻¹, respectively. We calculated the mean total ecosystem carbon stock to be 431 t ha⁻¹ (equivalent to 1,583 t CO 2 eq ha⁻¹). The Banja district bamboo plantation has the potential to sequester a total of 3,719,980 tonnes of CO₂. Effective community-based bamboo management strategies should be implemented to enhance these benefits.