Economic Value and Contribution of Carbon Storage in Different Organs of Eucalyptus and Acacia in the Flood Spreading Fields of Kowsar Station

Carbon storage by natural forests, plantation forests, pastures and soils is the best way to reduce atmospheric carbon. This study was conducted in 2018 with the aim of evaluating the effect of spate irrigation on the biomass and carbon storage in various organs of Eucalyptus camaldulensis and Acacia salicina plantation at the Kowsar station located in Gare-Bygone Plain. After truncating the trees, trunk, branches and leaves were separated. In addition, the amount of litter produced under the trees was also collected and weighed. Afterwards, the dried samples were powdered by electric milling and the carbon content in the samples including trunk, branch, leaf and litter was measured by electro-ash method. Data were analyzed using randomized complete block design and the means were compared by Tukey test at P<0.05. The results showed that leaves had the lowest amount of carbon storage and trunk had the highest amount of carbon storage. In eucalyptus stand (first strip), the highest carbon content of 187.56 t/ha was stored as living tissue including trunk, branch and leaf litter. Given that each ton of carbon equals 3.67 tons of carbon dioxide gas, it can be concluded that the amount of 688.34 tons of carbon dioxide gas in the air in different organs of the plant and in litter stored as organic matter. In acacia, however, the amount of carbon stored was 72.81 t/ha and the equivalent of stored carbon dioxide was 267.21 t/ha. The economic-environmental value of this amount of stored carbon was calculated to be $137619.05 and $5333.33 per hectare, respectively. With respect to 32 years of spreading water in these areas, each hectare of eucalyptus and acacia trees averages 21.51 and 8.35 tons of carbon dioxide gas have been stored as organic matter per year, respectively. In this respegt, the eucalyptus plantation has played a greater role in reducing air pollution. The economic value of the oxygen produced in the forests of eucalyptus and acacia ($11190.5 and $1774.28, respectively) is also adds to the economic value of reducing carbon dioxide, and their economic performance value reach to $148809.52 and $55238.10, respectively. Therefore, the development of eucalyptus afforestation toghether with spate irrigation method in similar prone areas is more economically justified and recommended from a carbon storage perspective.