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 C ha⁻¹ , respectively. We calculated the mean total ecosystem carbon stock to be 431 t ha⁻¹ (equivalent to 1583 t CO₂eq ha⁻¹). The Banja district bamboo plantation has the potential to sequester a total of 3719,980 tonnes of CO₂. Effective community-based bamboo management strategies should be implemented to enhance these benefits.