Mojtaba Akhavan Armaki; Hossein Azarnavand; Mohammad Hasan Asareh; Ali Ashraf Jafari; Ali Tavili
Abstract
Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. ...
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Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. Four genotypes of Bromus tomentellus pasture types were used (92 Tehran, 630 Kordestan, 3414 Shahrekord and 9507 Lorestan) and four drought care (-3, -6 and -9 times distilled water). In this essay the sprouting percentage, Root length, Shoot length, Seedling length, Root length to Shoot length rate, Seedling dry weight, Seedling fresh weight, dry to fresh weight rate sprouting rate and seed health index were determined. The result showed that the with stress drought increase, all attributes except the dry weight to fresh weight proportion reduced significantly. The reduction in all under assessment properties were from -3 to -6 in potential. In general, in tested genotypes, Lorestan (9507) genotype showed a better sprouting in under study potentials and had a meaningful preference to other genotypes. From assessed parameters, Seedling length and seed index standard showed the most possible reaction to changing potential of water. The best levels to assess the stability to drought were the -6 and -9 load potentials in all drought levels.
Jamal Imani; Hossein Arzani; Mohammad Ali Zare Chahouki
Abstract
For assessment and comparison of measuring density methods of Festuca ovina, Bromus tomentellus and prangos ferulacea, three plants communities are selected. In all of plant community, reference area was defined and samples 7000 (70*100) square meter was selected. Whole the area, sampling was accumplished ...
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For assessment and comparison of measuring density methods of Festuca ovina, Bromus tomentellus and prangos ferulacea, three plants communities are selected. In all of plant community, reference area was defined and samples 7000 (70*100) square meter was selected. Whole the area, sampling was accumplished as systematic-random. In each area, 5 transect 100 meter are established. Then in areas 7000 square meter, all of the basic species are counted by strip transect and real plant density is measured. This plant density is remarked as a control and plant density that is measured by others methods are compared with it. Density measuring methods in this research were: species counting counted in quadrate of 1 square meter, point-centered quarter, angle order, nearest-neighbor, random pairs and closest individual methods. The results showed that among these methods for Festuca ovina, neighbor nearest method is most accurate and angle order method has low accurate. Moreover angle order method is the slowest and quadrate method is rapid. In Bromus tomentellus, among these methods for this species, point-centered quarter method is the most accurate. Angle order method has low accurate in these methods. Also angle order method is slowest and counted quadrate method is rapid. In Prangus ferulacea, In these methods for this species, point-centered quarter method is the most accurate and angle order is the least accurate. Moreover angle order method is the slowest and count plant quadrate method is rapid.
Omid Bayat; Hamid Karimzadeh; Mostafa Eghbal; Hossein Khademi
Abstract
Despite of suitable geological and climatic conditions for forming and evolution of alluvial fans and importance of this landform as soil and water resources in arid regions, there are limited studies about this landform in Iran. In the present study, evolution and pedogenic development of geomorphic ...
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Despite of suitable geological and climatic conditions for forming and evolution of alluvial fans and importance of this landform as soil and water resources in arid regions, there are limited studies about this landform in Iran. In the present study, evolution and pedogenic development of geomorphic surfaces of an alluvial fan in Eastern Isfahan were studied by using remote sensing, field and laboratory analyses. Results show that watershed of studied alluvial fan was tectonically active and two main depositional events were occurred for fans of Eastern Isfahan. Geomorphic surfaces were identified according to topographic position and pedogenic development. Geomorphic surfaces of studied alluvial fan were identified using topographic position, dissection rate and pedogenic development of soils. Using of dissection index for geomorphic surfaces suggest that this index is more expedient for use in active surfaces. Soils on geomorphic surfaces are calcareous with distinctive carbonates morphology. Results of dissection index are in corroboration with carbonates morphology in soils of geomorphic surfaces. So, morphology of pedogenic carbonates can be considered as an index of relative age of geomorphic surfaces. Usage of clay accumulation index also show great corroboration with results of dissection index and morphology of carbonates and application of this index is recommended for paleosols. Suggested systems for paleosol classification truly able to classify paleosols and application of these modern models recommend for other regions.
Ruollah Taghizadeh Mehrjardi; Fereydoon Sarmadian; Gholem Reza Savaghebi; Mahmoud Omid; Nourayer Toomanian; Mohammad Javad Rousta; Mohammad Hasan Rahimiyan
Abstract
In recent years, alternative methods have been used for estimation of soil salinity. Therefore, at present research, 600 soil samples collected from Ardakan in central Iran. Then EM38 and terrain parameters such as wetness index, land index and curvature as readily measured properties and soil salinity ...
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In recent years, alternative methods have been used for estimation of soil salinity. Therefore, at present research, 600 soil samples collected from Ardakan in central Iran. Then EM38 and terrain parameters such as wetness index, land index and curvature as readily measured properties and soil salinity (0-30 and 0-100) as predicted variables were measured. After that, the data set was divided into two subsets for calibration (80%) and testing (20%) of the models. For predicting of mentioned parameters, ANFIS, GA, ANNs and MLR were applied. In order to evaluate models, some evaluation parameters such as root mean square, average error, average standard error and coefficient of determination were used. Results showed that the ANFIS model gives better estimation than the other techniques for all characteristics whereas this model increased accuracy of predictions about 17 and 11% for EC30 and EC100 respectability. After ANFIS model, GA and ANN had better accuracy than multivariate regression.
Meghdad Jourgholami; Vahid Rizvandi; Baris Majnounian Garagiz
Abstract
Assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. This study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. ...
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Assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. This study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in Gorazbon district in Kheyrud educational and research forest. The objective of this study was to assess soil disturbance from ground-based skidding system operation contribute to statistically significant changes in bulk density and penetration resistance at various depths below the soil surface and changes in bulk density and penetration resistance related to different traffic intensities. A systematic predetermined grid that was laid out prior to harvesting to measure soil disturbance, and pre-and post soil disturbance were recorded by a visual assessment. Soil compaction and penetration resistance were measured by using a double sampling method consisting of a hammer driven hand corer and a hand-held soil penetrometer. Bulk density and soil strength measurements were taken at three depths: 10, 20 and 30 cm. Detrimental compaction was recorded for the soil bulk density results. Detrimental compaction was recorded for the soil penetrometer after medium and intense machine passes. Post-harvest detrimental soil disturbance wasn’t exceeded the USFS maximum allowable area that can be detrimentally impacted. Soil resistance results demonstrated no detrimental compaction in area to the skid trail center and wheel ruts.
Gholam Ali Heshmati; Diana Askarizadeh; Rahim Forouzeh
Abstract
In order to determine the diet of Dalagh sheep, winter rangeland of Gomishan plain was selected. After delineating of the grazingland territory, rangeland condition and plant combination was determined by Range Value method and range trend was obtained by Trend Balance method. Time of bite-count record ...
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In order to determine the diet of Dalagh sheep, winter rangeland of Gomishan plain was selected. After delineating of the grazingland territory, rangeland condition and plant combination was determined by Range Value method and range trend was obtained by Trend Balance method. Time of bite-count record was done in morning and afternoon in a five-day period; first week of November (1389) and last week of April (1390). The diet selection of sheep was evaluated by direct vision method and comparison of the diet in two record periods was done by T-test and one way ANOVA method. Result showed that the most selection of sheep was Aeluropus littoralis (36/6% in a.m. & 33/3% in p.m.) and the minimum also was Halocnemum strobilaceum (1/01% in a.m. & 0/23% in p.m.) in first record. Lastly, the most selection of sheep was Hordeum marinum (42/99% in a.m. & 59/76% in p.m.) and the minimum also was Salicornia herbaceae (2/04% in a.m. & 4/16% in p.m.) Moreover, there is not any significant difference between grazing periods. Although shrub is the most species in the study area, diet selection of sheep was grasses form. It was for their growing phenology period that this time, grasses are palatable than halophytes shrubs.
Asghar Zare Chahouki; Ali Salajegheh; Mohammad Mahdavi; Sharam Khalighi; Said Asadi
Abstract
A flow-duration curve (FDC) illustrates the relationship between the frequency and magnitude of streamflow. Applications of FDC are of interest for many hydrological problems related to hydropower generation, river and reservoir sedimentation, water quality assessment, water-use assessment, water allocation ...
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A flow-duration curve (FDC) illustrates the relationship between the frequency and magnitude of streamflow. Applications of FDC are of interest for many hydrological problems related to hydropower generation, river and reservoir sedimentation, water quality assessment, water-use assessment, water allocation and habitat suitability. This study was carried out in 11 selected watersheds with common characteristics such as the 20 years period, the minimum land use change and similar annual water volume through all watersheds in 3 province of: Yazd, Semnan and Markazi which are located in central zone of Iran to regional flow duration curve. It was extracted Q5, Q10, Q20, Q30, Q40, Q50, Q60, Q70, Q80 and Q90 from 11 Hygrometric stations as a dependent variable were derived from flow duration curve. The flow duration curve is regionalized by using morphoclimatic characteristics of the drainage basin. Using multiple regression techniques, the geographic variation of each parameter of the best fitted flow duration model is explained in terms of the drainage area, length of longest flow, Stream slope, mean annual areal precipitation, course from the divide of the basin to the site of interest. The regionalized nonlinear regression equations are successfully used to flow duration curves at other locations within the hydrologically homogeneous regions of center of Iran. A cross-validation Nash–Sutcliffe Efficiency procedure was used to evaluate best fitting of the regional model in ungauged watershed.
Salahudin Zahedi; Farhang Ghasriani; Mina Bayat
Abstract
To study the effect of different harvesting intensity on forage production of Bromus tomentellus was considered of Majid Abad Qorveh. Treatments included four harvested intensity 25, 50 and 75 percent and control (no harvest).Data were analyzed based on splitplot over time during four years(1386-1389) ...
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To study the effect of different harvesting intensity on forage production of Bromus tomentellus was considered of Majid Abad Qorveh. Treatments included four harvested intensity 25, 50 and 75 percent and control (no harvest).Data were analyzed based on splitplot over time during four years(1386-1389) using SAS and IRRISTAT software. The results showed that the main effect of year, different harvesting intensity and interactions effect of different harvesting intensity and years are significant on forage production and vitality of Bromus tomentellus. Comparing the harvesting intensity of 50 and 25 percent indicated no significant difference between them. The highest intensity of production is harvest intensity of 25 percent with 390 mm perecipition in 1389 and the lowest harvest intensity is 50 and 75 percent with170 mm perecipition in 1387. Regarding to AMMI Analysis, the first interaction principal component(IPC1) had a significant effect and express a 93/6 percent of the interaction of the sum of squares. The first main component biplot interaction showed that the 25 percent treatments had a highest average production and stability is relatively good, control treatment had a lowest stability and 75 percent treatment had a highest stability. According to the results, to preserve the production and vitality of Bromus tomentellus the harvesting intensity of 25 percent is recommended.
Hamid Reza Saeidi Goraghani; Ghodrat alah Heydari; Hossein Barani; Zakaria Alavi
Abstract
This study is trying to exploitations view point and permanent management problems of rangeland to evaluate in ranches Damavand Summer Rangeland in Amol County. Statistical Society are utilizations 15 ranch that with three methods, collective property, private property and council property from rangeland ...
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This study is trying to exploitations view point and permanent management problems of rangeland to evaluate in ranches Damavand Summer Rangeland in Amol County. Statistical Society are utilizations 15 ranch that with three methods, collective property, private property and council property from rangeland utilization and randomly from among their number 88 was selected. The research tool was a questionnaire that among exploitations through direct interviews have been completed. To assess problems permanent management of rangeland in the area with pivotal effect of the structure of exploitation methods, index nine selection and with spectrum from exploitations view point and were measured. The results showed different methods on among permanent management of rangeland effect means confidence level 99 percent. Duncan comparison test showed that permanent management problems private property exploitation methods are low from exploitation methods collective property and council property. So Friedman test results showed that with the rank category index of problems permanent management of rangeland time stop livestock mid excessive pasture with average 9.23 and the number of livestock over rangeland capacity in the region with average 8.01, respectively, the uttermost rank or impacts than the other indexes on rangeland permanent management in watershed land. So with use from Kruskal Wallis test evaluated and compared each one of rangeland permanent management indexes in exploitation different methods. Generally recommended to reduce problems in watershed areas of before Projects of reform and reducing, recognizing systems, common law and the demands of exploitation more attention and emphasis management and experts.
Pejman Tahmasbi
Abstract
Fire is one of the most important ecological factors in semi-steppe rangelands directing plant community composition, diversity, structure and function of ecosystems. Our primary aim was to examine the effect of fire on plant community composition, diversity, plant species restoration and animal selectivity ...
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Fire is one of the most important ecological factors in semi-steppe rangelands directing plant community composition, diversity, structure and function of ecosystems. Our primary aim was to examine the effect of fire on plant community composition, diversity, plant species restoration and animal selectivity in semi-steppe rangeland in Karsanak region, Chaharmahal & Bakhtiari province in years 2005, 2008 and 2009. To do so, sampling was performed in burned and control areas using quadrates (2*2 m) installed along a 200 meter transect and plant cover, number of restored and grazed plant species estimated within them. There was a significant difference in plant community composition and diversity between the burdened and control areas in years 2008 and 2009. However, no significant difference was observed for year 2005. This may confirm that a four year period is needed to restore vegetation after fire. Most of graminoids species such as Agropron repense and Bromus tomentellus were restored by 90 and 80 percent respectively whereas, shrub species such as Astragalus adcendense and Astragalus susianus restored by 60 and 40 percent just one year after fire. The results also showed that animals selected burdened areas significantly more than controls in areas burned in 2008 and 2009, while the selectivity was the same for control and burned areas in 2005.
Sadat Feiznia; Asghar Kouhpeima; Hasan Ahmadi; Ali Asghar Hashemi
Abstract
Due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of Chasht-Khoran Basin in Semnan Province: Amrovan, Atari and Ali-Abad. Samples below 63 μm were separated and 15 fingerprinting propertis ...
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Due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of Chasht-Khoran Basin in Semnan Province: Amrovan, Atari and Ali-Abad. Samples below 63 μm were separated and 15 fingerprinting propertis was measured. In the first stage comparison of means and differentiation analysis were used for determination of the characteristics that can differentiate sediment source as well as possible. In second stage, by minimizing composite multivariate model by optimization methods, the share of each source was determined. The results shown that, in Amrovan Catchment, For properties consisting of Co, Ph , Kaolinite and K were recognized as optimum composition of sediment tracers which could differentiate sediment source completely. In Atary Catchment, the optimum composition of tracers are Na, Co, XLF and kaolinite which differentiate source by %91.7. In Ali-Abad Catchment five parameters were recognized as optimum composite which are :Na, XLF, Ca, Co and smectit which completely differentiated sediment sources. The results of calculated composite multivariate model have shown that Upper Red formation in Amrovan, Atari and Ali-Abad Sub-Catchment has the highest share in sediment production. The sediment production in these three sub catchment are as follows:35.9, 23.53 and 86.64% respectively. Therefore sediment management and control strategies should be performed on these sources.
Ali Akbar Mehrabi; Mohammad Mohammadi; Mohsen Mohseni Saravi; Mohammad Jafari; Mehdi Ghorbani
Abstract
Providing of landing use maps and detecting of land capacity are required to manage of natural resources and environment and planning of land use. On the other hand, it is necessary to detect of the human deriving forces affecting land use change. In this research, we selected Seyed mohaleh and Drasara ...
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Providing of landing use maps and detecting of land capacity are required to manage of natural resources and environment and planning of land use. On the other hand, it is necessary to detect of the human deriving forces affecting land use change. In this research, we selected Seyed mohaleh and Drasara villages in Tonekabon city. First, were provided the land use maps in 1987 and 2008 by using TM and IRS Satellite images. Second, were investigated the human deriving forces affecting land use change through survey methods. According to results of this research can state that had been destroyed much percents of forests and added residential and agricultural lands in two villages. The most important of land use changes in two villages related to the economic problems (low income) and the economic loss of agricultural activities. Recently, the most important deterrent forces of land use changes are the property market downturn and land price that can prevent of severe changes in land use through the implementation of efficient land use law and supporting of farmers and gardeners in this region. Moreover, the most important indicators in the intensification of land use changes are being a tourist area, increasing of land price and unemployment.
