Geostatistical analysis of aboveground carbon stock in Mopane forests

Tropical forests play a crucial role in regulating the climate and maintaining the global carbon cycle. Carbon is primarily stored in plant biomass. In Africa, these forests still present significant uncertainty in the carbon balance. This is due to scarce inventories and a lack of continuous monitoring. Mopane forests (Colophospermum mopane) are typical of dry tropical regions and have important ecological and socioeconomic roles. They are widely used by local communities. In Mozambique, charcoal production mainly drives degradation of these forests and loss of aboveground carbon (AGC). The aim of this study is to analyze aboveground carbon stock in Mopane forests in the Chicualacuala District, Southern Mozambique. The data used refer to georeferenced tree locations in a fragment of native forest. Aboveground biomass was individually estimated through a pantropical equation, using as predictor variables: diameter at breast height (DBH), total height, and basic wood density. From the biomass estimates, AGC was calculated and subsequently analyzed using geostatistical methods such as variograms and ordinary kriging. The results indicated that the ordinary kriging model partially captured the spatial pattern of AGC and, as evidenced by cross-validation, showed a moderate positive correlation (54.66%) between observed and predicted values. This level of correlation suggests that while the model provides a reasonable prediction of AGC, there is still considerable unexplained variability, which highlights areas for further model refinement or additional data collection.