Carbon stocks and sequestration potential of dry forests under community management in Tigray, Ethiopia

Introduction: Forests form a major component of the carbon (C) reserves in the world's ecosystems. However, little is known on how management influences C stocks of woody vegetation, particularly in dry areas. We developed regression models for two dominant tree species to predict C stocks and quantified the potential of community managed forests as C sinks. Methods: Plots were randomly selected from community-managed natural forest, herbivore exclosures, and from communal grazing land. Tree and shrub biomass were estimated using a regression model on the most dominant woody species while herbaceous biomass was determined using destructive sampling. Results: The simplest model, based on only one single predictor variable, showed a good fit to the data for both species (Juniperus procera and Acacia abyssinica). Diameter at breast height (r(2) > 0.95) was a more reliable predictor than height (r(2) > 0.54), crown diameter (r(2) > 0.68) (p < 0.001). The C content of the total biomass for the managed natural forest and the exclosure were estimated as, 58.11 and 22.29 Mg ha(-1), respectively, while that for the grazing land was 7.76 Mg ha(-1), and the mean carbon content between the three land uses were significantly different (p < 0.05). Conclusions: We conclude that forests managed by the community have a high potential for C sequestration and storage and their conservation should be promoted.