جستجوی مقالات مرتبط با کلیدواژه « بیستون » در نشریات گروه « محیط زیست »

Mountains are unique ecosystems which are described by variety and complexity. Extreme changes in topography and climatic and biological gradients with seasonal and fragile contrasts are characteristic of these areas. With increasing pressure on wildlife species, highlands play the role as the last wildlife sanctuaries. Altitude plays a key role in the formation of these areas which influences other environmental factors either direct or indirect. The altitude constraint in the use of land has been an obstacle to the severe development and consequently manipulation of these areas. In order to investigate the displacement of species of protected areas in the province, the observation of 17 species of birds and mammals in the province was identified then, the resistance map was prepared using weighting to different heights. The least cost path and circuit cape methods as well as the metrics related to each of them, were used to model and analyze the wildlife movement pathway. According to theoretical results, 15 habitat corridors with a length of 1363 km were identified. Bisotoun wildlife refuge and Bozin and Merkhil no hunting areas play the most important role in establishing the territorial communications of protected areas. Based on the results of the least cost analysis, 26 corridors with a length of 4317 km were modeled. Utility and density metrics of using the corridors in the least cost method indicated that the most desirable corridor for the displacement of wildlife species along the paths of the Bisotoun, Paraw and Khorin mountains is located on the Shaho Mountain.

The present research attempts to examine the quality of Gamasiab River and one of its main branches Bistoon ponds and also the impacts of such branch on the main river (Gamasiab) by using Hilsenhoff and Simpson index indices. The present study was conducted in a period of one year since 2014-2015 in 12 time periods in three stations. Benthic invertebrates were collected using Surber quantitative sampler, then fixed (Formalin %4) in laboratory and separated in laboratory using separation loop, and they were identified at the family level. In addition, while conducting sampling over benthic invertebrates variables at each station were measured as well. The greatest Simpson's Diversity Index was observed in the second station. Overall, 11 families of benthic invertebrates (totally, 5492), were identified in Gamasiab and Bistoon, which the highest the highest rate of density was related to Diptera present in all seasons at each three stations. Other orders (Gastropoda, Ephemeroptera, Amphipoda), were most frequencies in River. In this research 7 order (Diptera, Ephemeroptera,Trichoptera, Coleoptera, Pulmonata, Amphipoda, Clitellata) and 11 Famylies (Chironomida, Simuliidae, Tipulidae, Baetidae, Heptageniidae, Hydroptilidae, Elmidae, Planorbidae, Physidae, Gammaridae, Lumbricidae) were identified in Gamasiab and Bistoon Rivers.