Carbon Stock in Woody Plants of Humbo Forest and its Variation along Altitudinal Gradients: The Case of Humbo District, Wolaita Zone, Southern Ethiopia

Abstract

Forests play a critical role in the natural global carbon cycle by capturing carbon from the atmosphere through photosynthesis. However, Ethiopia does not have carbon inventories and databank to monitor and enhance carbon sequestration potential of different forests. As result, this study was conducted in Humbo forest with the overall objective of estimating the total carbon stock in woody plants and its variation along altitudinal gradients, as well as its implication for climate change mitigation. The above and below ground biomass, dead litter biomass and soil carbon were measured and estimated by using allometric equations. Trees with DBH>2.5 cm were measured for their height and diameter at breast height, and the result was analyzed by SPSS software, version 20. The findings of the study showed that Syzigium guineese(L.) Skeels was the most dominant and Prunus africana (Hook. f.) Kal was the least dominant one. The average carbon stock of the study area was 30.77, 14.46, 12.55, and 168.2 ton/ha, in above ground biomass, below ground biomass, dead litter, and soil, respectively. The variation of carbon pools between altitudinal gradient was not significant. The total maximum and minimum carbon stock estimated was 361.63 and 58.49 ton/ha, respectively, with the average value of 225.98 ton/ha. The estimated money term of carbon dioxide sequestered in one hectare was $6087.429 USD in average. This implies that the forest managed for carbon trading (to get money) indirectly sequesters about 829.35 ton /ha, in average.