نشریه محیط زیست طبیعی
سال شصت و سوم شماره 3 (پاییز 1389)

Siah Mahi، Capoeta capoeta gracilis، is a predominant fish in the river systems of the south Caspian Sea basin. Although there is evidence of the geographical divergence of this taxon، but no information is available on genetic differences within the subspecies populations. This study was designed to evaluate variation and differentiation in the Tajan River and investigation Shahid Rajaii dam effects upon Siah Mahi. A total 65 specimens were collected by electeroshocker set that 31 individual related to up stream station and 35 individual related to down stream station. Ten random 10-mer primers were primarily scored in 5 individuals from each of two stations and finally 6 primers، which shown polymorphic pattern repeatable، were selected and use in the final analysis of two locations. Totally 89 polymorphic band (marker) gained. Lengths of PCR products were between 50-1000 bp. Analyzing the PCR product data shown that the mean difference between the two stations was 0. 478. In view of the fact that in. /5 mean genetic distance between two species، separated those from each other، as a result related two stations in a large quantity separated from each other. Results of Principle Coordinate Analysis or PCOA showed that two stations are separated from each other. The unweighted pair group method with averages (UPGMA) dendrogram based on Jaccard´s index also showed these stations are separated. There are perfect similarities between results of morphometric factor and morphometric spacialities. Based on the results، we conclude that RAPD fingerprinting was a useful technique in genetic discriminating the population of Siah Mahi.

The aim of this study was to develop a methodology to identify suitable habitat of the Eurasian Nuthatch (Sitta europea) at kheyrood forest, northern Alborz, Iran. This study was carried out during spring to summer 2008. With attention to the area and topographic condition of kheyrood forest, Patom, Namkhane, Gorazbon, Cheler and Baharbon were selected as data collecting series. The present study focused on vegetation structure and floristics, as well as topographic factors (slope, elevation, and direction). In sampling stager at observation point in the line transect path, habitat parameters and presence and absence of nuthatches were recorded. In each plot all individuals that were observed or being heard, were designated as presence point and other cases were named as an absence point. Based upon this monitoring, 78 plots were collected as the presence and 20 plots were counted as absence point during spring season. Binary Logistic Regression was performed to develop the distribution model of the Eurasian Nuthatch according to habitat variables. Finally as a result, the significant parameters in this model were height, diameter, stand and type of trees. According to the results, suitable habitat for S. europaea was considered as all the forest areas where old-growth trees with large bounds are abundant. In fact habitat quality is related to the abundance of old trees. Also, the presence of Carpinus betulus and Fagus orientalis was identified as an important factor for habitat selection.

Armenian Gull Larus armenicus formerly listed as a subspecies for Herring Gull Larus argentatus and further introduced as a full species in 1980. This species mostly found in Caucasus and Middle East regions. Thair breeding areas are in Georgia, Armenia, Turkey and Iran. Meyghan wetland is an important wintering area for a number of migratory species especially for Common Crane Grus grus, furthermore it is the second suitable breeding habitat, (the Lake Uromiyeh is the first), for Armenian Gull, the only summer visitor species from Large-headed Gulls of Iran. This article is the result of field surveys which carried out in two breeding and wintering habitats. Survey about breeding of Armenian Gull in Meyghan wetland carried out in June & July 2008. This species breeds in islets which lie in eastern part of Mine road. The most wintering distribution of this species is in the north and west of Iran. Based on the reports between 2004 and 2007, the most of wintering population were in the West Azarbayjan province and after that was the Mazandaran province, and the least population belonged to Fars province. It highlighted importance of the Lake Uromiyeh for this species. Developing conservations levels and decrease the man made disturbance of these two wetlands, as main breeding and wintering habitat of Armenian Gull Larus armenicus in Iran, are the most important priorities for conservation.

Hyrcanian (Caspian) Forest in northern Iran with many endemic and endangered species is a rich area for biodiversity. The use of ground-based skidding is well accepted practice for the extraction of timber from the forest, but this has tended to cause the greatest environmental problems. The aim of the study was to evaluate and comparison of environmental impacts, residual stand damage, regeneration, and to quantify these effects such as: extent of the damage, wounding patterns, size and distribution after logging operations that utilized two different

short-log and long-log. A Timberjack cable skidder was used and the study location was in the Kheyrud Forest. Post harvesting assessment of damage to the residual stand was compared along skid trail by 100% inventory method and also for the assessment of regeneration damage along winching strips. The results showed that along winching strips the percentage of damage to the regeneration was 44 and 36 %, while the tree damages along skid trails reached 2.3 and 4.1 % in the short- and long-log methods, respectively. The greatest average amount of damage to a bole occurred along the first 1 m up from the ground (97%) and also within 4 m of the skidder centerline (80%). These results clearly show that the short-log method causes less damage to the residual stand than the long-log method. Tree location to the skidder trail appears to have a significant effect on the number and height of scars on a tree. Well designed and constructed trails should be wide enough to allow wood extraction from the forest. Damage to the residual stand might be reduced by proper planning and training of logging crews.

The accumulation of heavy metals Cd, Cu, Ni, Pb, V and Zn in the mangrove, Avicennia marina, was studied. Cu, Cd, and Pb were accumulated in root tissues to levels higher than surrounding sediments. Zn, Ni, and V were accumulated to levels lower than sediment concentrations. Pb and Zn showed little mobility to leaf tissue but Cu was accumulated in leaves with low concentration. Since Pb and Zn concentration in leaves was higher than earlier studies, it was recommended air pollution may have an important effect in this impression. Field observations depicted that the mangrove stand in Bushehr region receives high inputs of untreated industrial sewage, surface water run-off, and a range of air pollution diffuse inputs from oil and gas activities.

Isfahan wild sheep Ovis orientalis isphahanica is listed as vulnerable in the IUCN red list of threatened species. Adequate knowledge on habitat requirements and environmental factors determining the niche of a species is central to its conservation programmes. However, there is scarcity of data on habitat associations of this species in Iran. A GIS-based model, using presence-only data, was used to predict habitat suitability for this species in Mooteh Wildlife Refuge. This study has determined the most important environmental factors influencing the ecological niche of Isfahan mouflon and has identified suitable seasonal habitats in the study area. Results showed that during summer and autumn a large part of the suitable habitats of this species is covered with Artemisia aucheri, while in winter and spring areas covered with Artemisia siberi acquire the higher suitability. This is consistent with the vertical migration of the species as the results of this study revealed that in summer and autumn higher elevation has higher suitability, whereas in winter and spring the suitability of lower elevations is higher. Slopes over 30% and distance to water sources in summer were recognized as limiting factors for the distribution of this species. The influence of other factors (such as distance to roads, mines and cultivated lands) on habitat preference was negligible.

Maharloo Lake, located at 23 kilometers from Shiraz, has high value for local people and passengers due to its mild weather and natural interests. Studying recreational values of this place is necessary to predict needs, remove scarcities and tourism development. The aim of this research is to estimate the outdoor recreational value of Maharloo Lake with the use of contingent valuation method. To study the effective variables on willingness to pay per visit by individuals, logit model was used to estimate maximum likelihood. Requested data set were obtained by completing questionnaires and interviewing 188 individuals who visited the lake during summer 2007. Results revealed that 74.5 percents of individuals agreed to pay for each visit. Also results showed that education, lake absorption, gender and revenue had a positive significant effect and bid, number of yearly visits and family size had negative significant effect on probability of willingness to pay. Mean willingness to pay for each visitor per year was 3392 RLs and annual outdoor recreation value of Maharloo Lake was estimated 1187200000 RLs.

The evaluation of ecological characteristics of Wildlife species has fundamental role in species management, because taking a decision for proper method of management is only possible by characterizing of ecological requirements of a species. In this study, suitable habitat of Middle Spotted Woodpecker was investigated in Golestan National Park. Presence and absence of birds and environmental variables (forest cover types, topography, and structural characteristics of vegetation) were obtained within a 25-m radius of each of 106 sampling points distributed throughout the study area. Data analysis was conducted using binary logistic regression. The results showed that some habitat variables including the number of snags, tree species, height of trees, d.b.h of trees, and basal area were the most significant positive predictors affecting this species presence in Golestan National Park. Old and undisturbed forest habitats with characteristics such as high values of basal area, number of snags, d.b.h, and height of trees in Golestan National Park has the capability of supporting the 'umbrella' and sensitive species to the disturbance such as the Middle Spotted Woodpecker.