List of Articles عوامل فیزیوگرافی

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  1 - Investigation of the relationship between drought of Iranian oak trees with stand structure, physiographic factors and soil (Case study: Mian Tang forests of Ilam)
  Mehdi Ahmadi Ali Rostami
  10.30495/jrnr.2022.64785.10225
   The phenomenon of vegetation drought, especially in arid and semi-arid regions, has always been one of the main problems of various ecosystems. Numerous factors cause this phenomenon in plants, the most important of which are climatic factors (decrease in rainfall More

   The phenomenon of vegetation drought, especially in arid and semi-arid regions, has always been one of the main problems of various ecosystems. Numerous factors cause this phenomenon in plants, the most important of which are climatic factors (decrease in rainfall and increase in temperature) and the presence of pests and semi-parasitic plants such as loranthus. The aim of this study was to investigate the relationship between forest tree droughts and stand structure, physiographic factors and soil in the Mian Tang forests of Ilam province. For this purpose, after combining slope, direction and altitude maps, a sample plot was randomly implemented in each of the homogeneous units, and the quantitative and qualitative characteristics of the trees were measured in a circular sample plot with an area of 12 r. and recorded in census forms. According to the results, it was found that the decline of oak trees in the study area is affected by a combination of trees, stands and habitat. The results showed that 37.5% of the oak trees in the region were damaged by drought, of which 54% had a vegetative form and 58% of the damage was observed at the branches. The trees in the floors of 65, 60 and 50 cm in diameter and 8, 6 and 10 meters in height, as well as with canopy diameters of 8, 9 and 7 meters were more damaged by the oak decay phenomenon. The results also showed significant differences in some soil properties such as bulk density, electrical conductivity, organic matter, nitrogen, phosphorus and potassium in dry and healthy trees.  Manuscript profile
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  2 - Effects of Physiographic Factors on Density, Canopy Cover and Production Medicinal Species Ferula Orientalis (Case Study: Shohada Valley of Urmia)
  Masoomeh Abbasi Khalaki Ardavan Ghorbani Sahar Samadi Khanghah Rahman Rahimdokht
  10.22034/jest.2020.23843.3293
  Background and Objective: Plants are the major component of natural ecosystems including the rangelands which extend all they largely controlled by environmental factors and ecological, climate, soil, topography and biological properties are effective on their presence More

  Background and Objective: Plants are the major component of natural ecosystems including the rangelands which extend all they largely controlled by environmental factors and ecological, climate, soil, topography and biological properties are effective on their presence and traits. This study was performed in the Shohada valley of Urmia in order to evaluate the effect of physiographic factors on density, canopy cover and production of Ferula Orientalis. Methods: According to the current situation in the region, three height floors, three direction floors and seven slope floors were selected. Also, 8 sites were identified in the study area. In each site, 3 transects with a length of 100 meters were systematically-randomly plotted along each transect and 5 parameters were recorded. Analysis of variance was used to investigate the differences between the studied parameters and physiographic factors and Duncan's multiple range tests was used to compare the mean of the traits. Findings: Most density of studied species was observed in the 1700-2300 meters height class with 7,500 individuals per hectare. Also, the highest level of the species extends belong to slope of more than 70 percent with an area of 97 ha. The highest level of the aspect is related to East with 3/148 ha. Discussion and Conclusion: According to the results of this study, it can be said that the elevation, slope and aspect significantly have been effective on density, canopy cover and production of Ferula Orientalis. Generally the results showed that the highest density, canopy cover and production belonged to 1700-2300 meters altitude and on the slope above 70% and in the east aspect. Manuscript profile
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  3 - The relationship between the diversity of plant species and environmental factors in Vezg region of Yasouj
  Roghaye Aghaei سهراب الوانی نژاد Reza Basiri Roghaye Zolfaghari
  10.30495/jest.2023.76716.5959
  Background and Objective: The diversity is one of the most important issues in ecological studies, especially in vegetation ecology. This research aims to study plant biodiversity in relation to environmental factors survived in the southeast of Yasouj which is the cent More

  Background and Objective: The diversity is one of the most important issues in ecological studies, especially in vegetation ecology. This research aims to study plant biodiversity in relation to environmental factors survived in the southeast of Yasouj which is the central forests of Zagros ecosystem. Material and Methodology: For this purpose, a region with an area of 308 hectares was selected. Then, 61 plots (15×30 m) and 305 microplots (0.5×2 m) were established using random-systematic sampling method. The plots dimensions were also determined using minimal area method. To evaluate the diversity of plant species the most commonly diversity indices was used. Then, one-way ANOVA was used to examine differences in various classes. Findings: Results showed that elevation factor had a strong effect on species diversity and evenness as higher altitude showed higher amount of diversity and evenness. Aspect had significant effect on richness and marked the highest in the northeast. The results also showed that diversity and evenness were affected by slope and they are higher in 51-70 % of slopes. Also, the results indicated that there was a correlation between biodiversity indices with soil properties such as N, Silt and C/N ratio. Discussion and Conclusion: Overall, the results of this research in the region showed that, physiographic factors (altitude, slope and aspect) with soil properties always play a decisive role in the pattern of changes in plant biodiversity. So, of many studies carried out in this subject in Zagros forests, this is a very good one to achieve optimal management. Manuscript profile
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  4 - Evaluating effects of various physiographic factors and distance from road on timber marking using multiple linear regression model
  Hamid Jalilvand Maryam Niknejad Mohammad Hejazian
  One of the forest management tools which has a direct impact on the qualitative and quantitative characteristics is timber marking. In order to evaluate the effects of physiographic factors of land and road forms on timber marking for the logging, the multiple linear re More

  One of the forest management tools which has a direct impact on the qualitative and quantitative characteristics is timber marking. In order to evaluate the effects of physiographic factors of land and road forms on timber marking for the logging, the multiple linear regression model was used in the Forestry Plan Series 2 in the seventh zone of forestry plans of Nekachoub Company, Mazandaran province. For this purpose, the location of marked trees was determined using GPS in a plot with an area of 215 hectares. Then, maps of marked trees, altitude, aspect and slope percent, soil and distance from the road were prepared in GIS environment using these points and digital elevation model of study area. To understand the relationship between factors and marked trees, the multiple linear model was used. So, maps of mentioned factors and marked tree's location were entered into the regression model as independent and dependent variables, respectively. The model results showed that the timber marking activity was done more in the areas with low altitude, gentle slope and deep soils on northern and eastern directions near the forest road as compared to the other areas. Timber marking is affected by some physiographic factors, and such elements as slope or adjacency to the road may make the timber marker to interfere in these areas and avoid working in the areas with higher slope or away from the road; it leads to an uneven interventions throughout the forest as well as an unbalanced reclamation of forest structure. Manuscript profile