Carbon stock in woody plants and its variation along environmental variables of Bela Mountain Forest, northern Ethiopia

Dry Afromontane forests are important carbon sinks, yet the influence of topographic gradients on their carbon stocks remains insufficiently understood. This study assessed aboveground carbon (AGC), belowground carbon (BGC), litter carbon (LC), soil organic carbon (SOC), and total carbon (TC) stocks along altitude, slope, and aspect gradients in Bela Mountain Forest, northern Ethiopia. Data were collected from 108 georeferenced plots (20 × 20 m), with nested litter and soil subplots (1 × 1 m). Descriptive statistics, assumption tests, one-way analysis of variance (ANOVA), Tukey’s HSD, Kruskal–Wallis tests, and multivariable models were used. Mean total carbon stock was 108.81 t ha⁻1, with SOC accounting for 75.3% and AGC for 19.8%. Altitude significantly influenced AGC (p = 0.0037), BGC (p = 0.0036), LC (p = 0.0107), and TC (p = 0.0306), whereas slope and aspect showed no consistent effects. Multivariable models identified altitude as a significant negative predictor of all carbon pools, while slope effects were weak or nonsignificant. These findings identify altitude as an important determinant of carbon-stock variation in Bela Mountain Forest and highlight the value of incorporating topographic gradients into the management and conservation of dry Afromontane forests.