Prediction of the vegetation management impacts on reduction of wind erosion risk in the southern parts of the Varamin Plain, Iran

Wind erosion is a major environmental issue affecting land resources and socio-economic settings in Iran. This paper outlines a study undertaken to provide a new tool to manage wind erosion from physical and economic perspectives. The southern part of the Varamin Plain in south of Tehran is used as a case study. The focus of this study is on exploring the economic and physical impacts of 16 vegetation-based scenarios for wind erosion management as well as conducting a trade-off analysis using the Multi-Criteria Decision Making (MCDM) technique. This involves developing a modeling system to assist decision makers in formulating scenarios, analyzing the impacts of these scenarios on wind erosion, and interpreting and suggesting appropriate scenarios for implementation in the area. The Iran Research Institute of Forests and Rangelands (IRIFR.1) model has been selected to create the wind erosion hazard maps for the present condition and for the possible vegetative management scenarios. The Spearman’s correlation coefficient indicated a high conformity between the hazard classes of wind erosion map predicted by the IRIFER.1 model and ground evidences. Using the Delphi method weights of wind erosion, gross margin, and establishment costs indices have been determined 0.5, 0.3, and 0.2, respectively. This indicates the high importance of wind erosion issue from experts’ consideration. Standardization and trade-off analysis of indices showed that a scenario with a combination of all possible management actions ranked as the best scenario (highest score) despite incurring the largest establishment costs. On the other hand scenarios with single management actions resulted in lowest scores. Finally, the sensitivity analysis of the chosen modeling approach in this study indicated the robustness of the results

The Physiological and Biochemical Responses of a Medicinal Plant (Salvia miltiorrhiza L.) to Stress Caused by Various Concentrations of NaCl

Salvia miltiorrhiza, which is commonly known as Danshen, is a traditional Chinese herbal medicine. To illustrate its physiological and biochemical responses to salt stress and to evaluate the feasibility of cultivating this plant in saline coastal soils, a factorial experiment under hydroponic conditions was arranged on the basis of a completely randomised design with three replications. Five salinity treatments (0, 25, 50, 75 and 100 mM NaCl) were employed in this experiment. The results showed that salinity treatments of <100 mM NaCl did not affect the growth of Salvia miltiorrhiza in a morphological sense, but significantly inhibit the accumulation of dry matter. Salinity treatments significantly decreased the Chl-b content but caused a negligible change in the Chl-a content, leading to a conspicuous overall decrease in the T-Chl content. The Na(+) content significantly increased with increasing hydroponic salinity but the K(+) and Ca(2+) contents were reversed, indicating that a high level of external Na(+) resulted in a decrease in both K(+) and Ca(2+) concentrations in the organs of Salvia miltiorrhiza. Salt stress significantly decreased the superoxide dismutase (SOD) activity of Salvia miltiorrhiza leaves in comparison with that of the control. On the contrary, the catalase (CAT) activity in the leaves markedly increased with the increasing salinity of the hydroponic solution. Moreover, the soluble sugar and protein contents in Salvia miltiorrhiza leaves dramatically increased with the increasing salinity of the hydroponic solution. These results suggested that antioxidant enzymes and osmolytes are partially involved in the adaptive response to salt stress in Salvia miltiorrhiza, thereby maintaining better plant growth under saline conditions