Climate Regulation and Soil by Development of Green Space in an Arid Zone

The simplest and most economical technique to reduce CO2 of atmosphere and climate regulation is carbon sequestration in plant and soil by development of vegetation and green space. Impact of afforestation and soil fertility on soil carbon sequestration and climate regulation was investigated, in two 15-year old stands of needle-leaved (Pinus eldarica) and broad-leaved (Robinia pseudoacacia) in 2 areas with different irrigation treatments (municipal effluent and well water) and also a control area (without afforestation), in an arid zone (south of Tehran). For this purpose, sample plots (30 m × 30 m) were systematic-randomly chosen in either of both stands. In each sample plot, four soil profiles were dug to take the samples in depths of 0-15, 15-30 and 30-60 cm. In laboratory, soil organic carbon (SOC) content of soil samples was determined by the Walkley–Black method. The results demonstrated that in each stand there was a significant difference (p<0.01) in the amount of soil carbon sequestration between two irrigation treatments (municipal effluent and well water). No significant difference in the amount of soil carbon sequestration of two stands was detected, but each stand sequestered higher carbon content in soil compared to that of in control area. In two studied stands, with increasing of soil carbon content, growth parameters and biomass significantly (p<0.01) were increased. With regard to more average of wood biomass and carbon sequestration and be evergreen of elder pine trees, can say that afforestation of eldar pine in comparison with block locust has more role in decreasing of air pollution and climate regulation.