فهرست مطالب jahangir feghhi

The Caspian Kutum (Rutilus frisii) is one of the most important bony fish speciesof the Caspian Sea and has high conservation and commercial value. There were decreasingtrends in its catch levels in the last years. Identifying temporal trends of its catch could helpadopt proper plans to maintain the stocks of this important species and achieve sustainableexploitation goals. In the present study, we conducted a time-series analysis for catch data ofthe species over a decadal period.

The commercial catch data of Caspian Kutum, over the seine netfishing points of the northern coastal regions of Iran during catch seasons 2002/03 to 2011/12,were used as catch-per-unit-of-effort (CPUE). A 5-point moving average of CPUE was used todistinguish the fishing points as optimum (with normalized CPUEs ≥ 0.6) and non-optimum(with normalized CPUEs < 0.6) fishing locations. Time series modeling was conducted usingthe seasonal autoregressive integrated moving average (SARIMA) model based on seasonal 3-month intervals. The performance and predictive ability of the models were assessed using aset of indices, including Akaike’s information criteria (AIC), Bayesian information criterion(BIC), root mean squared error (RMSE), normalized root mean squared error (nRMSE), meanabsolute error (MAE), normalized mean absolute error (nMAE) and the Pearson correlationcoefficient (r). CPUE trends over the five years of 2013 to 2017 were predicted using the bestfittedSARIMA models.

Five optimum (HR) and six non-optimum ranges (CR) were identifiedover the whole fishing points range (WR). The fitted SARIMA models based on the whole dataof all fishing locations as well as classified optimum and non-optimum ranges of fishinglocations did not have significant non-seasonal autoregressive and moving averagecomponents, indicating no increasing nor decreasing trends for CPUE over the study period,while for some of the ranges of fishing points, there were significant autoregressive and movingaverage components with clear seasonal increasing trends. The overall trend of CPUEs showedmainly an increase from 2002 to 2006, and then after relatively constant levels, there weredecreases from 2009 to 2013. The obtained predictions from the models for data sets havingsudden temporal fluctuations were less accurate. In contrast, higher accuracy levels ofpredictions and trends were observed for fish catch time series with no sudden alterations inCPUE levels over the studied period. Most of the obtained predictions for 2013-2017 similarlypresented stationary fluctuation trends with apparent seasonal increases in CPUEs.

Time-series modeling for R. frisii using the SARIMA method mainly indicatedclear increasing seasonal trends without any general trend of change over the whole fishingpoints. The simplicity of the obtained models considering the obtained seasonal and nonseasonalcomponents could be explained by the short time frame and the low number of datapoints. However, spatial classification of fishing points resulted in more detailed models andhigher recognition potential of them. The findings of this research could lead to a betterunderstanding of the temporal trends in catch levels of Caspian Kutum and use them by fisheriesmanagers to adopt efficient management plans regarding the available stocks of this species inthe future.

In terms of natural structure and geographical location, our land has major constraints on the biological and sustainable production of biological systems, and most of its biomes are forests that naturally have fragile biological systems and, if exploited outside their capability, they are simply exposed to destruction. Therefore, due to the multifunctional nature of forests, it is necessary to assess the environmental impacts of forest management plans. The main purpose of the present study is to evaluate the impacts of forest activities as well as planning to minimize and prevent negative environmental impacts and maximize the positive environmental impacts of the Lirehsara forest management plan using the destruction model approach. In this regard, environmental degradation modeling was performed to determine the environmental impacts of forestry activities in the Mashalak Forest. In this study, compartments were selected as the impact unit. After determining the degradation factors, 14 identified factors were included in the model and the final destruction map was created. The results of the degradation model showed that the study area was divided into four zones of potential development, requiring restoration 1 and 2 and requiring conservation measures. Accordingly, 49.70% of the study area was in degradation class 1 and susceptible to development, 35.15% and 9.78% in degradation class 2 and 3, respectively, in need of restoration and 5.3% in degradation class 5 and in need of protection measures. According to the results of this study, it is recommended that protection measures and further development in the area be prioritized and remedial measures for forest protection should be considered. One of these measures could be the elimination of the destructive factor of the mine and the other non-accumulation of waste in the forest.

Biodiversity is important in human performance and interference in natural environments. Investigation on biodiversity in main forest communities makes the improved management of these valuable ecosystems possible. The aim of this research was the comparison of biodiversity in four major forest communities in Hyrcanian forests.  The four forest communities (i.e., Fagetum, Fageto-Carpinetum, Querco-Carpinetum, Parrotio-Carpinetum) were surveyed by full-callipering method in Patum District of Kheirood forest. Applying the collected data, the biodiversity of them were studied in three levels of trees, shrubs and seedlings. Biodiversity was studied among the mentioned three levels in each association and among the communities separately. The results showed that there was no significant difference among the applied indices (Simpson, Shannon-Wiener and Brillouin) in the study area. Also Shannon-Wiener index decreased in order from Querco-Carpinetum to Parrotio-Carpinetum, Fageto-Carpinetum and Fagetum. There was no significant difference among the associations in the biodiversity of shrubs. The diversity of shrub species in the study area is also independent of the diversity of tree species and seedlings. The study of Shannon-Wiener index showed that the studied communities are different from each other in terms of species diversity, which should be considered in the development of management strategies. Finally, it should be noted that in sustainable forest management should be sought to preserve the diversity of plant species and prevent its decline.

Tree green space has a remarkable positive effect on neighboring land and building prices mainly due to its shading and aesthetic quality. Yet, this value are often overlooked. This paper aims to estimate the effect of tree green space on building price in Jahanshahr neighborhood of Karaj city. Hedonic pricing method was used to value tree green space. The data on 220 residential real estate transactions in 2016 within study areas were obtained from the state-owned Rahbar informatics services company. Spatial information and characteristics of neighborhood and tree green space were collected using QuickBird satellite image and Arc Gis10/3 software. Tree green space neighboring studied buildings was quantified using the percentage of tree crown cover within different radius window surrounding the properties. Then, the optimal radius providing the highest correlation between tree cover and building prices was used in the hedonic model. The findings showed that the characteristics of building and tree green space have significant effects on per-m2 price of buildings. The optimal radius used to calculate tree cover around residential buildings found to be 300 meters. Price elasticity revealed that every 1% increase in the tree cover raise the per-m2 price by 0.6% at the sample mean. Therefore, tree green space in Jahanshar with average tree cover of 29/4 % raise the per-m2 price of buildings by 17/6 %. The results also showed that a 1% increase in the road distance to closest park reduces the per-m2 price of buildings by 9.1%. Finally, % morexpensive.

Currently, Iranian Forest resources planning is dominated by national, regional and sub-regional planning causing numerous damages to forests. In this study, the necessity of using a spatial forest resources planning process for macro management of country's forest resources and presenting the analytical model to the current practice has been investigated. Given the nature of macro perspective of spatial planning which contains various development plans and environmental protection simultaneously, the selection of this model provides a suitable strategy in the process of macro forest resources planning. The model presented here was conducted using qualitative analysis, citation analysis and content analysis. In the proposed model, the development process uses the nature of the performance and function of forest ecosystems based on the structure and biological processes of the ecosystem (Ecosystem analysis). On the other hand, the process employs the correlation between human and nature (Human Ecology).‌ This model can be conducted in five stages including analysis of the existing conditions of customary forest areas, evaluation of ecosystem services supply, assessment of forest resources demand, determining the units of management and optimizing the distribution of services. By implementing the spatial forest resource planning, a sustainable approach can be achieved in planning the forest resources of Iran.

Forestry cooperatives are among the few formal institutions to involve local people in natural resource management. Therefore, many efforts have been made to hand over natural resource management to forestry cooperatives. However, there are many issues regarding the success of forestry cooperatives in achieving planned objectives. In the present study, the performance of forestry cooperatives of Kurdistan province in Marivan, Sarvabad, and Sanandaj counties was evaluated. Capacity development scorecards were used to assess cooperatives' performance in four criteria including conservation, restoration and rehabilitation, development, and utilization of forest resources and indices corresponding to each criterion were used based on the forestry plans. The statistical population of the study consisted of the managing directors of six registered forestry cooperatives and experts in charge of cooperatives affairs in the Natural Resources and Watershed Management Organization of the Kurdistan province. Data were collected through field observations and interviews. The results showed that in terms of built capacity, Negel Cooperative was in better condition, and Barghrrou Cooperative was in poor condition. The mean score of conservation, restoration, and development criteria for all cooperatives was close to 1 and 2 for utilization criterion in the level of built capacity. This level indicates that measures are planned to be implemented, however, lack of funding, lack of oversight over implementation, scarcity and inadequacy of budget, temporal actions in initiation years, and limitations of the taken actions, lead to failure in meeting the objectives. Efforts are needed to redefine the cooperative institution and its expected tasks and roles in the field of renewable natural resources management. Hence, responsible organizations need to take more vigorous actions to empower forestry cooperatives.

Yellowfin tuna, Thunnus a lbacares , are the most important ecological and economic fishes in the Persian Gulf. In recent decades, their populations have faced overfishing, environmental problems and climate change. In this study, using some environmental variables affecting the habitat of tuna fish, i.e. sea surface temperature at night and day, reflection of 645 nm wavelength as a water turbidity, angstrom view of aerosol 443 to 965 nm, aerosol optic thickness at 869 nm, organic and inorganic particle carbon, photosynthetic active radiation, absorption by phytoplankton at 443 nm and chlorophylla concentration from 2002 to 2018, on the spatial distribution of yellow-fin tuna has been modelled by fuzzy rule-based classification. Over the years, the variables had different degrees of importance in the models. There was a great variation in the spatial distribution of the species from year to year.

Height Measurement of all trees in a forest or forest stand is almost impractical. For this reason, today different researchers prefer to estimate the tree height by the relationship between the DBH and height of trees.

In this study, to fitting different statistical models in different stages of forest development, after field inspection, three one hectare sample plots located in different development stages in Beech forest of Kheirud forest, Natural Resources Faculty in Tehran University were selected. Then the DBH of 251 trees have been measured randomly and 80 percent of trees were used for modeling and 20 percent were used to validate 22 regression models. In order to determine the best model for each of development stages, R2, E, MBE and NMPE criteria were used.

The results of this study indicated the suitability of Rational Function and Weibull models in initial stage, Modified Exponential in optimal stage and Gompertz and Richard models in Decay stages.

Based on the results of this study it can be concluded that different regression models doesn’t have the same ability in fitting the data of DBH and height of different forest stands and the same model can’t be used to fit the data of DBH and height of different forest stands.

The northern mountains of Tehran are amongst the most valuable natural ecosystems in Iran, which have been destroyed in recent decades due to improper use of land and land-use changes. Therefore, studies on the land-use changes via spatial occurrence probability maps are necessary to deal with this phenomenon. In the present study land use/land cover of 2000 and 2017 were mapped using Landsat satellite images by supervised classification method and maximum likelihood algorithm for the Kan watershed in the Tehran Province. In order to determine the most important factors affecting land-use change as well as zoning the probability of changes, digital data of biophysical (nine variables) and human (four variables) factors were analyzed in the GIS. Finally, the map of probability of land-use changes was produced by applying logistic regression. Validation of the model was performed using relative operating characteristic, which indicated the high ability of the model to describe the changes and determine the areas prone to changes. The results showed that about 60% of the Kan watershed is classified as highly prone to land-use changes. In those areas, variables such as elevation, aspect, slope, soil depth, average growing season precipitation, and average growing season temperature were identified as the most important factors affecting the land-use changes. Conclusively, the results of this research indicated significant land use/cover changes in the studied area during the recent years, as well as a high occurrence probability of future land-use changes.

The Paliurus spina- christi species grow naturally in three different vegetation regions of Iran (Northern forests, Arsbaran and Zagros forests). But so far no research has been carried out on the sites of this species. Therefore, present study was conducted to investigate the effect of environmental factors on distribution of ecological groups in Paliurus spina- christi site in the Northern forests of Iran. To consider different condition of the study area, sampling was done based on land units and size of square-shaped plots was 400 m2 that it was determined by minimum area method. After recording existing data in each plot, soil samples were collected from the sampling plots. Then, vegetation data were classified by Two-Way Indicator Species Analysis (TWINPAN) using PCORD software and finally, Canonical Correspondence Analysis (CCA) were used to investigate the relation of each plant species and environmental factors, by CANOCO software. According to the results of TWINSPAN, there were four vegetation types in the study area. The results showed that different species, such as Pyrus cerasifera, Berberis vulgaris, Punica granatum, Cupressus arizonica and Carpinus betulus are indicators species of the study area, replace of Paliurus spina- christi. Also, the results of CCA showed that amount of C/N, N, saturated water content, bulk density, porosity, clay, phosphorus and soil potassium are effective factors on distribution of vegetation in Paliurus spina-christi site. On the other hand, C, organic matter, sand, silt, altitude, slope and aspect have not significant effect on plant ecological groups. According to results, the presence of Paliurus spina-christi is directly related to amount of N and bulk density. In this study, it was clearly shown that using CCA, it is possible to determine the relationship between each plant species and the most important environmental factors.