Diameter Distribution Models and Carbon Sequestration Potential of Afi Forest Reserve, Cross River State, Nigeria

Abstract

Forest managers can make well-informed judgments, including prescribing silvicultural treatments, by being able to forecast the distribution of diameters in a stand. This study calculated the carbon potential of the Afi River Forest in Cross River State, Nigeria, and created and verified models for diameter distribution. For this investigation, two transects totaling 1500 meters in length were used, separated by 500 meters. There were ten sample plots per 1500m transect, or a total of 20 sample plots in the study area, with 50m x 50m sample plots spaced 100m apart throughout each transect. Measurements were made of the diameter at the breast height, the diameters at the base, middle, and top, and the overall height of 1368 individual tree species, distributed among 23 species from 18 distinct tree families. The average tree volume and biomass were found to be 12.01 m3 and 80.72 kg, respectively, while the mean diameter at breast height (dbh) and total height were measured to be 25.8 cm and 18.5 m, respectively. At stand level, mean basal area of 48.95m2ha-1 was attained with a mean volume of 244.561m3 ha-1and mean green biomass was 448.860ton ha-1with a dry biomass of 325.423ton ha-1. Diameter Distribution models were created using the Easy Fit program. Three diameter distribution models were validated for the reserve based on their post-development rankings. Nevertheless, among the chosen diameter models in the reserve, the Log-Logistic (3P) distribution model was determined to have the best fit. Since none of the chosen models was statistically significant, the diameter distribution of the study region can be modeled using all three of the fitted and validated models.