جستجوی مقالات مرتبط با کلیدواژه "سمیرم" در نشریات گروه "اکولوژی"

Nowadays, medicinal plants are being used to cure ailments and improve health. The vegetative form and biological shape of plants establish a clear relationship with specific environmental and human factors. The purpose of this study was to study the vegetative form, geographical distribution and therapeutic application of indigenous medicinal plants in Semirom rangelands. Medicinal plant species were collected from different areas of Semirom rangeland and transferred to Isfahan Agricultural and Natural Resources Research and Training Center for identification. After identifying the flora of the region and separating the medicinal plants, the data were collected by submitting a questionnaire to the knowledgeable and knowledgeable locals of the area (villages and tribes) about the use of medicinal plants. In this, study 62 plant species were identified in April and November of 94 and 95 belonging to 21 families and 53 genera in the region. Apiaceae with 12 species, Lamiaceae with 10 species and Asteraceae with 7 plant species were the most abundant.  According to the results of interviews with locals, most of the traditional uses of medicinal plants in rangelands of Semirom were dedicated to the treatment of gastrointestinal diseases. In terms of biological formations, hemicryptophytes with 24 species (39%) were the most abundant and biodiversity and elements of the Irano-Turanian area with 19 species represented 38% equivalents.

In order to investigate the effects of range management plans on species diversity, richness and evenness in Semirum rangelands, 52 sites (28 with treated plan and 24 without treated plan) were selected. The non-parametric indices for species richness (Margalof, Menhinick, Jacknife and counting method) and species diversity (Simpson, Camargo, Smith and Wilson and modified Nee) were compared in two management plans. The mean comparisons were made by independent T Student Test and Mann-Witheny U Test, and correlation was determined between diversity indices and vegetation parameters. Based on the results there was no significant difference between the two management systems regarding environmental features, while the implementation of range management plans caused significant reduction of stocking rate. Among the studied indices, evenness of species in sites without treated plan was significantly more than the sites with treated plan. The correlation matrix showed that there was a significant positive correlation between species richness and vegetation cover, production of perennial plans, and the rangeland condition and trend, while evenness showed significant negative correlation with these indices. Generally, implementation of range management plans has considerable effect on increasing climax species, dominance of Bromus tomentellus and it causes improvement of rangeland condition and reduction of evenness. This behavior could be explained by the balance between species competition and grazing pressure. Further, succession process of the studied communities demonstrates domination of some desirable species, high production and less diversity.

The objective of the present study was to investigate the pasture vegetation changes using satellite data in Semirom، Isfahan province. This study was conducted in 2004 as a wet year and 2009 as a dry year. The WiFS and AWiFS satellite images were acquired and used for the year 2004 and 2009، respectively. First، the vegetation percentage was simultaneously measured in the two years. Then، considering the environmental factors such as elevation، slope، and slope direction، climatic factors and vegetation indices were derived from the above satellite data and multiple regression equations were prepared using step-wise regression analysis. The intended regression model for each year was used to produce percentage of vegetation cover of the study area. For a suitable pasture vegetation map interpretation، the reclassification technique was used to separate the rangeland use from other land uses، and then the density slicing method was applied. Using suitable thresholds، the rangeland vegetation cover classes including 0-20، 20-30 and 30-40 percent canopy covers were determined. Results showed that the changes in vegetation classes were related to each other and by increasing the area of one class the other one decreased. It was found that the 30-40% and 20-30% classes changed most، and the maximum increase was observed in the 0-20% vegetation cover class due to the area degradation in the other two classes.