Ali Mohebbi; Moslem Mozafari; Ehsan Zandi Efahan; Ali Ashraf Jafari
Volume 26, Issue 3 , September 2019, , Pages 543-550
Abstract
A significant area of the country's rangelands is degraded due to various factors and an important part of rangeland species is endangered or their population is severely reduced. Rangeland improvement and reclamation through selecting suitable species and finding the best cultivation methods are of ...
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A significant area of the country's rangelands is degraded due to various factors and an important part of rangeland species is endangered or their population is severely reduced. Rangeland improvement and reclamation through selecting suitable species and finding the best cultivation methods are of utmost importance in these rangelands. Therefore, according to the results of the research project performed in the Research Institute of Forests and Rangelands, the seeds of Sa.arbuscula were collected from different rangelands of Semnan province along with the existing populations. The study was conducted in a randomized complete block design with three replications at Semnan Research Station since 2011 for five years. The data were analyzed using SAS software and the means were compared with Duncan's test. Our results clearly showed that among the study accessions of Sa. arbuscular, the genotypes 230 and 234 with an establishment percentage of 86.67% and 84.02% were superior, respectively. Therefore, the genotypes 230 and 234 could be recommended for rangeland improvement and reclamation.
Hosein Arzani; Hamidreza Mirdavodi; Mehdi Farahpour; Mojganolsadat Azimi; Seyed Hasan Kaboli; Abasali Sanadgol; Morteza Akbarzadeh; Valiollah Mozafarian
Volume 12, Issue 4 , August 2019, , Pages 409-436
Peyman Madanchi; reza Bayat; Kaka shahedi
Volume 24, Issue 4 , January 2018, , Pages 757-767
Abstract
Soil is one of the most important resources in each country and if it is not protected it will be lost due to erosion and gradually loses its fertility. Soil loss will fill the stream channels, reservoirs and cause serious damages like decreasing crop production per unit area. This ...
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Soil is one of the most important resources in each country and if it is not protected it will be lost due to erosion and gradually loses its fertility. Soil loss will fill the stream channels, reservoirs and cause serious damages like decreasing crop production per unit area. This study was conducted to evaluate the effects of watershed management practices including mechanical and biological measures to reduce erosion and sedimentation in Daremorid watershed in Kerman province. In this study, MPSIAC model parameters such as surface runoff factor, land cover factor, land use factor, current state of erosion factor, channel erosion factor, and sediment behind small dams were used. The results showed that the sediment yield was estimated to be 36653.38 tons per year which is more than the sediment yield calculated in preliminary studies in this watershed (51378.46 tons per year). Based on statistical analysis using SPSS software, the results revealed that there were significant differences between sedimentation and erosion, particularly in each of the parcels in the watershed.
Hosein Arzani; Hasan Kaboli; Hamid reza Mirdavoodi; Mahdi Farahpoor
Volume 15, Issue 3 , January 2008, , Pages 320-347
Abstract
Importance of permanent range assessment is advice, because of continuous change, ecological aspects and economy of rangelands. The wide area of rangelands and facilities limitation for regular monitoring cause the requirement of the remote sensing application. The objective of present study was investigation ...
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Importance of permanent range assessment is advice, because of continuous change, ecological aspects and economy of rangelands. The wide area of rangelands and facilities limitation for regular monitoring cause the requirement of the remote sensing application. The objective of present study was investigation on reliability of ETM+ data for vegetation estimation. The study was carried out in Markazi province for five years. Satellite data of same time of grand truth data was obtained for each year. Vegetation indices were calculated after radiometric and geometric correction of images. Canopy cover of annual species, herbaceous species, grasses, shrub and total cover in five sites during five years were measured. Measurements were carried out in 60 plots two square meters rectangular quadrates along four 400 meter parallel transects. Before processing of the information, 15 random selected quadrates were kept for test of equation. In other case all data of four years was applied to calculate equation between vegetation indices and ground data and data of fifth years was used for test of model. Considering small area of quadrates against 30*30 meter pixel and probability of error involved with coordinate measurement by GPS correlation between mean data of each transect and indices also was studied. The results obtained from equation were compared with actual cover data using student t-test. Most indices have significant correlation with cover data, however sometimes equation did not gave correct estimation of cover compared with actual data. This was happened for life form that did not make considerable percent of vegetation composition. Generally application of transect data and calculation of equation based on four years data to estimate of fifth years canopy cover was more suitable way of using satellites data. Certainly using satellite system with more bands and better resolution and doing soil background correlation in arid regions would give better results.
Hosein arzani; Mahdi Adnani; Hosein Bashari; Mojgan azimi; Hosein Bagheri; Morteza Akbar zadeh; Hasan Kaboli
Volume 13, Issue 4 , February 2007, , Pages 296-313
Abstract
Rangelands have important role in economy of country because of providing forage for animals, soil and water conservation and other services giving to society. Therefore their careful management is necessary. To do this, main vegetative stepic regions of Qum province were ...
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Rangelands have important role in economy of country because of providing forage for animals, soil and water conservation and other services giving to society. Therefore their careful management is necessary. To do this, main vegetative stepic regions of Qum province were selected. In each community a key area was determined to establish a permanent site, so eight key areas were selected in the whole province. In each site four parallel, 400 meter transects were established. Canopy cover and yield within 60 quadrates in two square meter areas, along each transect were measured each year. According to the results, Qum's rangelands contain poor vegetation composition with low cover percentage and yield. Desirable species were absent in vegetation composition and moderate and non-desirable species made major part of vegetation cover and yield. Most Qum's rangelands suffer from over grazing and should be recovered by a suitable management program. Results showed significant relationships (P<0.05) between canopy cover and forage yield of studied species during 6 years (1999-2004). However regression models calculated based on correlation between cover and yield varied due to seasonal condition in each year.
Mohammad Jafari; Fatemeh Panahi; Hasan Ahmadi; Hamid reza Abbasi; Mohammad Musavi; Mohammad ali Zare; Ali Tavili
Volume 13, Issue 3 , February 2006, , Pages 278-283
Abstract
The desertification phenomenon with all the problems it causes , most great effect will remain in soil, so by assessing soil variations we can reach the intensity of desertification. In the Iranian model for desertification assessment some indices including EC, soil depth, soil texture and the amount ...
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The desertification phenomenon with all the problems it causes , most great effect will remain in soil, so by assessing soil variations we can reach the intensity of desertification. In the Iranian model for desertification assessment some indices including EC, soil depth, soil texture and the amount of subsoil gravel are recommended in order to assess the intensity of desertification. Here, we chose fields in different environments such as Soleyman, low desertification risk, Gazeran, desertification risk & Hossein Abad Mish Mast, already desertified field. We selected 5 profiles in each station and studied topsoil and subsoil layers in each profile and measured soil’s physical and chemical properties in the laboratory. We used spilt plots design to regard different properties of soil in each station in topsoil and subsoil and their effects on each other. In order to appoint the desertification potential in each area and in each soil unit we used the formula following: where x is score of soil indicator and x are scores of Ec, depth, and texture and subsoil gravel rate. The obtained results based on this formula indicate that the desertification of each area is moderate. Statistical analysis showed a meaningful difference for gravel and texture. The results of Duncan test selected Soleyman and Gazeran stations in one unit subset. The method used here is designed according to soil information bank and apt to arid and semiarid climate. Of its defects we can point the unreality of its scoring because there is just 4 degrees for the intensity of desertification which limits the range of scoring. Certainly in order to evaluate the desertification phenomenon we should match the results with other sections’ results. Their results will help to precede the desertification evaluation and present indices fit to Iran pattern and conditions.