Papers by Dr S. F. Afzali
Estimating the Wind Erosion Climatic Factor Using Regional Distribution Function
Comparative Assessment Of Carbon Sequestration Rate And Biomass Carbon Potential Of Young Shorea Robusta and Albizzia Lebbek
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Page 1. International Journal of Hydro-Climatic Engineering Assoc.Water and Enviro-Modeling Jana ... more Page 1. International Journal of Hydro-Climatic Engineering Assoc.Water and Enviro-Modeling Jana et.al.(pp.1-15) eISSN - 99990001 1 Comparative Assessment Of Carbon Sequestration Rate And Biomass Carbon Potential Of Young Shorea robusta and Albizzia lebbek ...
International Journal of Environmental Science and Technology, 2019
Changes in soil organic carbon (SOC) can lead to increased concentration of carbon dioxide (CO 2)... more Changes in soil organic carbon (SOC) can lead to increased concentration of carbon dioxide (CO 2) in the atmosphere and eventually contribute to climate change. Simulation models are useful tools to evaluate the effect of future scenarios of climate change on soil CO 2 emission in the long term; this study aimed to: (1) evaluate the performance of RothC model using SOC data measured from five different vegetation covers in a semiarid region (southern Iran); (2) assess the impacts of present climate and climate change scenarios on cumulative CO 2 emissions from soil; and (3) assess the net effect of climate change on soil CO 2 emissions by comparing the two scenarios. The following vegetation covers were studied: rangeland, cypress trees, almond trees, cypress understory and almond understory. Model validation indicated that RothC accurately simulated SOC measured data (R 2 = 0.97; Pearson correlation = 0.98; performance efficiency = 0.96). Results showed that climate change effect on soil cumulative CO 2 emissions increased by 2050 under all vegetation covers, although not significantly in each vegetation cover in comparison with the present climate scenario. The extent of soil cumulative CO 2 emissions may be related to the different decomposability of plant materials and soil carbon input (plant material quantity) in tree covers and rangeland/understory covers, respectively. However, vegetation covers with the highest and lowest soil cumulative CO 2 emissions did not correspond with the highest and the lowest values of soil CO 2 emissions under the net effect of climate change. In addition, trends of the soil CO 2 emissions were decreasing in all vegetation covers during the 2014-2050 period. We argue that under the net effect of climate change SOC will be resistant against further decomposition over time. In fact, easily decomposable materials are fully or partially depleted, and microbial population and decomposition rate of litter materials will decline. This also implies a chemical change of organic matter and the formation of humus complex compounds showing a high resistance to decomposition. Therefore, the study of organo-mineral complex and humus complex compounds in the soils of this region is recommended for future researches. Keywords Climate change • RothC model • Soil cumulative CO 2 emission • Net effect of climate change • Quality and quantity of plant material * S. F.
The adverse effects of salinity and PEG-induced water stress on growth of Matricaria chamomilla w... more The adverse effects of salinity and PEG-induced water stress on growth of Matricaria chamomilla were assessed at the germination stage using osmotic solution of NaCl (0, -0.175, -0.358, -0.541, -0.716 MPa), and polyethylene glycol (PEG 6000) (0, -0.05, -0.1, -0.2, -0.3 MPa), respectively. Effect of NaCl salinity stress (0, 40, 80, 120 and 190 mM NaCl) at early growth stage of chamomile was also studied. The levels of NaCl and PEG-induced water stress were determined in first experiment. Both seed germination rate and seedling growth reduced with increasing osmotic potential of growth medium either due to NaCl or due to PEG. However, PEG-induced osmotic stress caused more growth inhibition compared with NaCl-induced osmotic stress. Seeds were not germinate at -0.8 MPa of NaCl and -0.4 MPa of PEG. In conclusion, adverse effects of salt stress on germination and early growth of chamomile is due to Na + accumulation in addition to its osmotic stress.
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Papers by Dr S. F. Afzali