stimating potential of urban forests for atmospheric carbon sequestration

co2 is the main greenhouse gas which urban forests have a high potential to absorb and sequestrate it. the air pollution of tehran is one of the most important environmental problems of the iran. to do this research 40 years old stands of robinia pseudoacacia and fraxinus rotundifolia and the surrounding barren land ( as blank) were selected in chitgar forest park of tehran and the amount of carbon sequestration of biomass(above and belowground), litter and soil(0-15 and 15-30 cm) were measured. the results indicated that the stands of r. pseudoacacia and f.rotundifolia have respectively caused the carbon sequestration of 9.63 and 3.5 mg c ha-1 yr-1 and increased the potential of carbon sequestration about 482.5 and 140 mg ha-1 respectively. the economical values of carbon sequestration through mentioned stands were calculated 20 and 2.5 millions dollars respectively. the most share of total carbon sequestration was allocated to trunk biomass of trees (61% in r. pseudoacacia and 51% in f.rotundifolia). the percentage of sand ph, and nitrogen were respectively of the most important factors effective on soil organic carbon. the results of this research confirmed the high potential of urban forest in carbon sequestration. therefore regarding to the iran membership in climate changes convention, the suitable management and conservation of this urban forest and other similar urban forests of tehran and other regions of iran should be done in order to decrease the density of atmospheric carbon, global warming and climate changes.