جستجوی مقالات مرتبط با کلیدواژه "ilam" در نشریات گروه "منابع طبیعی"

In this research, one of the most important functions and services of the forest, the function of maintaining soil nutrients in the forests of the Dalab watershed in Ilam province, has been valued. First, the amount of erosion and sedimentation in the study area was checked using the modified MPSIAC model in the current condition. By developing two scenarios of converting the (current) natural forest with 30 to 50% canopy cover to bare land through scoring the model, the changes in the amount of erosion and sedimentation were estimated. Next, the amount of soil nutrients was determined by soil sampling and laboratory analysis. Then, taking into account the difference in the amount of erosion in the state of natural forest (current) with 30-50% canopy cover and bare land, the amount of each nutrient element in the soil, and the loss of soil nutrients was also calculated. Then, using the replacement cost method, the service value of forest ecosystem soil nutrient maintenance was estimated. The results showed that the studied forest can maintain 2.52 tons of phosphorus, 35.55 tons of potassium, and 251.96 tons of nitrogen per year with an approximate value of 2,275,700 million rials per year and prevent its loss due to erosion. Also, the value of each hectare of forest for this function was estimated at 88.13 million rials. The estimation of the value of this ecosystem service in Zagros forests indicates the very effective role of forest ecosystems in controlling erosion and protecting soil nutrients.

In the last two decades, the vast areas of Zagros forests especially in Ilam province have been infected by charcoal oak disease, which killed many Persian oak trees. This study aimed to recognize the structure of the infected stands and to address the relationships between structural features and the tree characteristics with the infection level to the symptoms of charcoal oak disease. For this purpose, a number of 20 sample plots was established along a 6 km transect in Dalab protected forest to collect data such as collar diameter, diameter at breast height, height, crown area, and tree drying degree were measured and recorded for each tree within the sample plots. The number of tree bases was 153 and the surface area was 14.6 m2/ha, indicating a relatively high density and inventory of forests. In general, 85.5% of the individuals had a sign of the charcoal disease and the rate of infection was higher in seed-originated trees, middle-aged and old trees than branching bases and young ones. Based on the results, tree characteristics including collar diameter, diameter at breast height, basal area, total height, and crown area were significantly different among different infection levels of the disease. To understand the dynamics of stands’ structure under the charcoal disease, continuous monitoring of the forests is necessary. Since the higher severity of the disease outbreak in middle-aged and old trees, pruning and shrinking the infected trees’ crown to adjust the crown to root ratio as well as cutting and removing the trees which are not restorable are among the proposed practical plans.

Changes in land uses are of the human interventions influencing ecosystem processes. In this study, some soil properties and clay mineralogy have been studied in three land uses including a combination of oak forest and dry farming, dry farming and 20-years-old abandoned dry farming in Karezan region. Soil samples were taken from control profiles of each land use and the soils were classified based on key soil taxonomy 2014. The results of soil properties showed that the highest ρb is 1.59 gr/cm3 in surface horizon belonged to 20 year- old abandoned farming. The lowest soil pH in surface horizon belonged to combination of oak forest and dry farming usage with amount of 7.28 and the highest belonged to 20 year- old abandoned farming usage with amount of 7.61. OM in combination of oak forests and dry farming usage was 1.15 % which was higher than other usages. The highest percentage of lime in surface horizon belonged to 20 year- old abandoned dry farming usage .The highest CEC in surface horizon belonged to a combination of oak forest and dry farming usage with amount of 24.56 cmol+/kg. In all land uses, all measured metal oxides except calcium oxides were decreased from surface to the depth of soil. Also, except calcium and magnesium oxides, the rest of metal oxides had a decreasing trend from the top of slope downwards. Clay mineralogy by X-ray indicated that Vermiculite, Kaolinite, Illite and Chlorite composed the main parts of clay minerals and different usages did not affect the type of identified clay minerals.

The western forests and rangelands of Iran in Zagros habitats have mainly been destroyed by various reasons in recent years. The preparation of the land cover map in these sites is the first step to protect them and to prevent further destruction. The aim of this research was to select the best algorithm for land cover mapping in a part of Ilam site using the Sentinel-2 image. After providing Sentinel-2 the supervised classification of it was performed by seven different algorithms (maximum likelihood, minimum distance from the average, mahalanobis distance, spectral angle mapper, spectral correlation mapper, support vector machine, neural network). For accuracy assessment of the land cover maps, the stratified random points were created and found in the field. In the field visit, after determining the current land cover of each point in the plot area, the real land cover of each point was compared with the defined land cover of the same point in the pixel area based on classification results and the accuracy of the algorithms was evaluated. The results showed that the support vector machine algorithm had the highest accuracy in providing the land cover map with a general accuracy of 79% and a Kappa index of 0.70. The analysis of the land cover map obtained from this algorithm showed that the dense forest area was 319.64 ha, semi-dense forest area was 361.44 ha and sparse forest area was 1832.36 ha from the total area of the study area (16085.31 ha). Also, the rangeland area was 7352.78 ha, the garden area was 62.32 ha, the agricultural area was 658.42 ha and understorey agriculture was 4504.64 ha. For optimal management of this sensitive ecosystem, land cover mapping using this algorithm in certain temporal intervals is essential to investigate the forests and rangelands change and to control the human-made land uses.

Oak is the dominant forest species in the Zagros mountains, it is seen as a semi dense forest in western provinces. Multiple droughts, development of cities and villages, land use change from forest to farmland, are the main causes of forest destruction in Ilam. The purpose of this research is to determine the change detection of forest land to other land uses, using multi temporal TM sensor images (April 1986) and OLI (April 2015). In object-based classification, the data segmentation as initial phenomena, with appropriate scale and compression parameters for each image, was performed. Two classifying phenomena, nearest neighbor method and fuzzy functions were used. Land use classes were prepared by specifying training points and using the normalized difference vegetation index (NDVI). The Overall accuracy of the TM image was 88% and OLI image 94%, and the kappa coefficient for the TM and OLI image was calculated 84% and 91%, respectively. By post classification comparison method, the change matrix for each districts and changes forest to other uses was formed. The results showed that all districts faced with the phenomenon of deforestation and forest wide change (-42%) have been made.

Oak forest in west of Iran has been always considered by terrorists. So, site selection with emphasis to passive defense principal is really necessary in this area. This research aimed to site selection of defense installations and determine of suitable areas of its generation in the part of thin forests at Ilam province using analytical hierarchy process (AHP) and Geographic information system (GIS). By using defense expert opinions, and a literature review eight effective intelligence layer in determining the talented defensive centers (lithology, distance from urban, distance from rural, slope, aspect, elevation, distance from drainage and distance from road) were selected and their maps were digitized in ArcGIS®9.3 environment. Prioritizing factors were done using expert opinions in the Expert Choice (EC2000). The results by priority criteria by pairwise comparison method showed that distance from residential areas (urban and rural area), distance from roads and lithology 0.351, 0.222, 0.160, and 0.109 had the highest effects on defense site selection, respectively. In contrast, elevation (0.021) and distance from the river (0.030) had the lowest effects. Finally, the results showed that Cenozoic geology units, distance from city 10000-15000 m, distance from roads >6000 m, slope percentage (10-20%), eastern aspect, elevation (1000-1500 m), distance from river >3000 and distance from roads 3000-5000 m were the most important factors for presentation of potential maps for building of military centers in the western forest area of Ilam.

This study was conducted to determine the precision returns of range plans of Karhpo range plan, Ilam by engineering economy methods based on the data and information collected. The results showed that the criterion of net present value (NPV) had a positive net value to a discount rate of 26.00%, while its effect was zero at a discount rate 26.56%. Besides, the benefit-cost ratio (BCR) was higher than 1 until the discount rate of 26%, while it was equal to 1 at the discount rate of 26.56%. Internal Rate of Return (IRR) of 26.56% for plan was economically practical during 9-years period. Given the proper financial explanation of the plan, it is better to adopt a method and policy for assigning and implementing the range plans to beneficiaries in order to making ranchers more willing to implement the plans. The government can also participate more actively in range plans with providing parts of the costs and improving economic efficiency (return) of plans.

This study was aimed to identify the fish species and their abundances in Godarkhosh River, Ilam Province. Sampling was done using an electro shocker device equipped by 200 volts electricity generator from 5 different stations throughout the river within 100 meters of each station. Fish specimens at each station were caught, in triplicates, according to the Zypyn method specified for closed condition. Samples were immediately fixed by formalin, transferred to the laboratory and identified based on their meristic and morphometric characteristics using the identification key books of fish. Results showed the presence of eight species belongs to three different families. Cyprinidae was the most abundant family (92.4%) with six species from different genera. Nemachilidae and Mastacembelidae families each by one species had also 6.28% and 1.31% of the species abundance, respectively. Fish species captured in this study were included Garra rufa, Cyprinion macrostomum, Capoeta trutta, Alburnus mossulensis, Carasobrbus luteus, Mastacembelus mastacembelus, Tor grypus, and Oxynoemacheilus frenatus. The most abundance species was Cyprinion macrostomum (31.3%) followed by the Alburnus mossulensis (29.4%) and G. rufa (24.4%). Mastacembelus mastacembelus (1.05%) had also the lowest abundance among the fish species.

The purpose of this study was to investigate the influence of tree canopy density, DBH (Diameter breast height), vertical crown classes (upside, amid and beneath), physiographic factors (elevation, aspect and slope) on mistletoe infection intensity in central Zagros forest ecosystems in the north of Ilam, Bankol region (approximately 120 ha). For this study, random systematic method and 62, 1000 square meter plots were selected. Results showed that foothill direction had significant effect on infection intensity, while elevation and slope percentage hadn’t any effect of infection. Most numbers of mistletoes was in southern direction. Results also showed that vertical crown classes had significant effect on infection and upside crown had high infection both for Quercus brantii and Acer monspessulanum. Maximum infection intensity was in region with canopy opening innuendo 0-25%.The results indicated that most infection has happened in middle DBH classes namely 30,35,40.In this region Quercus brantii and Acer monspessulanum with 80% and 16% have had most shrub numbers of mistletoe.

Oak (Quercus brantii) is one of the most important tree species in Zagros forest that its natural regeneration has been disturbed specially in recent years. In this research, Oak (Quercus brantii) regeneration and their relation ship with environmental factor in a part (approximately 100 ha) was investigated. A part of Ghalarang protected area located in north of Ilam province (approximately 100 ha). In order to study the vegetation, inventory method of randomsystematic with 100´200 dimensions network and sampling plot area of 20m ´ 20m were selected. Totaly, 50 sampling plots were harvested. In order to analyze of data, multivariate methods of TWINSPAN and CCA were used. Five ecological species groups were found using multivariate methods. The results showed that, there are significant differences in natural regeneration of Quercus brantii (with sprout and seed origin) between the groups. Quercus brantii regeneration (with seed origin) had positive correlation with elevation, aspect, organic materials, nitrogen and SP and, the mentioned species regeneration (with sprout origin) had positive correlation with bulk-density and aspect. The results also showed that elevation and aspect had significant effect on Quercus brantii regeneration. The elevation over 2000 m and north aspect had high Quercus brantii regeneration (with seed origin), whereas the elevatio below 1500 m and south aspect had high Quercus brantii regeneration (with sprout origin).

Zagros ecosystem is considered as one of the most important biological sites in the country. This ecosystem is very important in terms of size (40 percentage of total forest), flora and fauna species, genetic reserves, under story vegetation and such like. Considering the large number of traps and ranchers in this region, having the essential details and information about the plant species diversity is highly important in order to revive the vegetation in the area. For evaluation of plant species diversity and richness of herbaceous species related to physiographic factors, part of DALAB area in north of ILAM approximately 1000 ha in central Zagros forest was selected. For this study 320 plots (2×2 meter) on different aspect transect were selected and in each plots all of herbaceous and surface covers evaluated. The results of this study showed elevation had significant difference on plant species diversity and richness, low altitudes class (1600>) has the most, while the high altitudes class (1800<) has the least diversity. Results showed that aspect had a significant impact on plant species diversity and richness of herbaceous species and Plant species diversity and richness higher in south aspect than other aspect though it did not have any significant difference with regard to evenness. The results also showed that the slope had significant effect on plant species diversity and richness and heist plant species diversity and richness in <30 slope class.

Acer monspessulanum is one of the valuable species in the Zagros forests. One of the major problems is the nursery is the amount and frequency of irrigation.Traditionally, Acer seedlings are irrigated on a daily basis, however, so far, there has not been any scientific account specifying the exact amount of water needed for the irrigation of this specific species. Considering the importance of water as an essential factor for plant growth, especially in the early stages of growth and its impact on qualitative and quantitative characteristics of seedlings in nursery production, irrigation and its frequency and rate must be investigated in the nursery scientifically in order for seedlings to be grown with higher quality and chances for establishment in nature. In this study, some morphological features of Acer monspessulanum were investigated under different irrigation treatments 2, 4, 6, 9 and 11 days once in a temporary nursery (three hectares) in Dareh-Shahr city in the northeastern of Ilam province. Each treatment consisted of 30 pots (30 seedlings) and each treatment has three replicates. The results of this study indicates that there is a significant difference with regard to the morphologic particulars (Leaf area, leaf fresh weight, leaf dry weight, shoot fresh weight, shoot dry weight, root dry weight, shoot length growth, collar diameter, length and number of branches branch) between attendance of different Irrigation period and 4 days Irrigation period showed the highest mean value of morphologic particulars. This result can be considered as a highly significant one as far as the saving water in our Country and other dry or semi – dry countries. The entire sapling in 11 day Irrigation Period was dead. Percent survival and quality index of seedlings after planting seedlings in the field had highest value in In 4 days once irrigation.