Abstract
Forest contributes 50% of climate change mitigation potential. Forest serves as a natural sinker of atmospheric CO2 to mitigate climate change. Although a number of studies have been done on carbon stock estimations the influence of environmental factors on forest carbon stocks has not been properly addressed. This study was conducted in Zomba Forest, with the objectives of estimating the carbon stock and its variation along the altitudinal gradients. A reconnaissance survey was carried out across the forest in order to obtain an impression in site conditions and physiognomy of the vegetation and collect information on accessibility.
The systematic stratified sampling method was employed in two strata to collect data and altitude was the major parameter to consider. Data collection was done by field inventory and secondary data from different sources. In order to collect vegetation data a total of 62 plots (31 quadrants in each stratum) each with the size of 20 m x 20 m at an interval of 100 m, were laid along the established transects at 300 m apart. For litter and soil sample collection, five sub-quadrants 1 m x 1 m were established at four corners and center of every quadrant. Data analysis of various carbon pools measured in the forests was accomplished by organizing and recording on the excel datasheet and MINITAB software version 17. Results revealed that the total mean carbon stock density of Zonba Forest was 316.48 t/ha with aboveground biomass carbon of 155.83t/ha and belowground biomass carbon 40.5158t/ha litter biomass carbon 5.157 t/ha and soil organic carbon 114.977 t/ha. 138.31t/ha and 173.35t/ha AGC, 35.961t/ha, and 45.071t/ha BGC, 106.931t/ha and 123.041t/ha SOC, 5.024 t/ha and 5.291t/ha were recorded in upper and lower altitude respectively. Therefore, a higher amount of carbon was recorded in lower altitudes than upper altitudes. The result of this study showed that altitude has no significant impact on carbon pools except soil organic carbon. Based on the overall ecosystem carbon stock result of the site was on the good status and it can contribute to climate change mitigation.
Keywords: Biomass Carbon, Soil Organic Carbon, Ecosystem carbon, Dry afromontane natural forest, Carbon stock density.
