Jalal Abdollahi; Hosein Arzani; Naser Baghestani; Mohammad Hasan Rahimian
Volume 13, Issue 3 , February 2006, Pages 162-171
Abstract
Remote sensing is a method to produce updated information in vast area. Describing the model for utilization and processing satellite data in regard to developing a method for mapping forage production of arid regions were the purpose for this study. For this purpose Landsat ETM+ data used at Nodushan ...
Read More
Remote sensing is a method to produce updated information in vast area. Describing the model for utilization and processing satellite data in regard to developing a method for mapping forage production of arid regions were the purpose for this study. For this purpose Landsat ETM+ data used at Nodushan area in 2002 . The study area covers about 60000 hectares and the annual precipitation is about 140-300 mm. in order to correct the necessary data 50 sites with different vegetation types using 25 quadrant of 1*2 m size and then awareged were used. To study the dependent variable of vegetation relations with independent variables of satellite data, vegetation indices and environmental factors; multiple linear regression analysis were manipulated using SPSS software. Then a suitable model was selected which caried predict the vegetation properties of the study area. Finally, production map was produced using ILWIS software. According to the results, mapping of forage production via remote sensing is possible even when its vegetation cover is less than 25%.
Ebrahim Rahmani; Ali ashraf Jafari; Pooya Hedayati
Volume 13, Issue 3 , February 2006, Pages 172-185
Abstract
Mountain rye (Secal montanum) is one of the most important forage grasses for pasture establishments. It grows for grazing and hay production in the north and west mountains of Iran. In order to determine the best population for pasture establishment in Lorestan province, Iran, 10 ecotypes of mountain ...
Read More
Mountain rye (Secal montanum) is one of the most important forage grasses for pasture establishments. It grows for grazing and hay production in the north and west mountains of Iran. In order to determine the best population for pasture establishment in Lorestan province, Iran, 10 ecotypes of mountain rye, were evaluated for seed yield, and its components. Two separate experiments were conducted under optimum and drought stress conditions using complete block design with three replications in Brojerd Agriculture Research Station, during 2003-2004. The data were collected and analyzed for flag leaf length, stem height, spike length, spike number per plant, peduncle length, seeds number per spike, forage dry matter yield, seed yield, 1000 seeds weight, harvest index, date of spike emergence and date of pollination for each environment and combined over 2 environments. Results of analysis of variance showed that ecotypes 2382M with average values of 394 Kg/h had higher seed production over both environment. The ecotypes of 2382-6 and 2382-13 with average values 3.93 and 4 ton/h had higher forage dry matter production over two environments. In general, ecotype 2382-13 with an average values of 4 ton/h forage production and 382 kg/h seed production was introduced as the best varieties for pasture establishment in areas of northern Lorestan province.
Seyed Alireza Mousavi; Mahdi farahpour; Maryam Shokri; Karim Solaimani; Mahmood Godarzi
Volume 13, Issue 3 , February 2006, Pages 186-200
Abstract
Landsat 7 ETM+ satellite data of 2002 versus vegetation cover map of 1976 were used to: 1- assess the capability of satellite data to prepare vegetation cover classes map and 2- study the vegetation changes trend in an area of about 26858.6 ha in Lar Dam Basin. Field Sample spots were defined after accomplishing ...
Read More
Landsat 7 ETM+ satellite data of 2002 versus vegetation cover map of 1976 were used to: 1- assess the capability of satellite data to prepare vegetation cover classes map and 2- study the vegetation changes trend in an area of about 26858.6 ha in Lar Dam Basin. Field Sample spots were defined after accomplishing necessary corrections of satellite images. Suitable band compositions were selected by considering the Optimum Index Factor (OIF), correlation matrix, Principal Components Analysis (PCA) and 2-dimensional diagram analysis. These compositions were classified using Maximum Likelihood, Minimum Distance and Box Classifier algorithms and then Majority Filter was used. Accuracy of resulted maps was evaluated by pixel to pixel method. Then Overall Accuracy Coefficient and Kappa Index were calculated. The map resulted from classification of band composition 123457 through Maximum Likelihood and Majority Filter was selected as the vegetation cover map of 2002. Vegetation cover map of 1976 prepared by Asgari-khah (1977) via field survey was used as "vegetation cover classes" map of that year. Then the changes happened in each class were assessed by operation of cross function on the mentioned maps. Due to complexity of initial classes, more homogenous classes were merged resorting to more detectable maps having only four classes. Overall Accuracy Coefficient of final map was promoted by using these classes. Then the changes happened during 1976-2002 were detected. The results showed that 28.55% of total area which was covered by rangeland vegetation types in 1976, is unchanged, 14.03% is dropped into lower and 57.42% into higher classes. The map of vegetation cover changes was produced, finally.
Hamid reza Mirdavoodi; Hojat... Zahedi; Masud Shakoei; Javad Tourkan
Volume 13, Issue 3 , February 2006, Pages 201-211
Abstract
The initial step of each phenomenon is complementary recognizing and understanding of its relationship with other effecting and affecting phenomena. Regarding rangeland vegetation as the first chain of nutrition in rangeland's ecosystems, recognition of its homogeneous areas and vegetation type classification ...
Read More
The initial step of each phenomenon is complementary recognizing and understanding of its relationship with other effecting and affecting phenomena. Regarding rangeland vegetation as the first chain of nutrition in rangeland's ecosystems, recognition of its homogeneous areas and vegetation type classification seems necessary. The present study was carried out in order to determination the most effectiveness ecological factors on vegetation types using Multivariate data analyzing. For that vegetation type was determine of type using GPS together with field survey and drawing map of the areas on the 1/50000 scale. Some data layers for each of vegetation type including density and cover percentage, climate, the mean elevation classes, mean annual rainfall, the mean slop, mean annual temperature, land types and Geographical aspect of the areas were collected and analyzed using Statistica program package and the method of factor analysis. The results of factor analysis shows that between applied variable, three main variables including climate, land types, and Geographic aspect with Eigenvalues of 82.8 are the most effectiveness ecological factors on vegetation types. Using cluster analysis rangelands classified in to 22 groups of Markazi province. the groups were confirm by Discriminate Analysis method.
Taghi Mirhaji; Abbas ali Sanadgol
Volume 13, Issue 3 , February 2006, Pages 212-221
Abstract
The phenological stages of five species Festuca ovina, Koeleria macrantha, Koeleria phleoides, Melica cupani and Melica jacquemntii were studied for three years(2003-2005) in Homand-e-abesard rangeland research station, in 70 km east of Tehran. Annual life cycle of plants were divided into two ...
Read More
The phenological stages of five species Festuca ovina, Koeleria macrantha, Koeleria phleoides, Melica cupani and Melica jacquemntii were studied for three years(2003-2005) in Homand-e-abesard rangeland research station, in 70 km east of Tehran. Annual life cycle of plants were divided into two large periods, more active and less active phases. data were recorded in the first phase every 7 days and in the second phase every 15 days. The Growth degree-days(GDD) were calculated for each phenological stages. 20 stands of each species were studied. The phenological stages include: growth initiation(gi), vegetative growth(vg), heading out(ho), full flowering(ff), seed ripening(sr), seed maturity(sm), temporary dormancy(td) and regrowth. The result showed that the five species started their growth from early March and dried in late July. There was dormancy for late August to early October and a regrowth stage from late November to late December. The Growth degree days were calculated for each phenological stage of 5 species in the different years. The result showed no GDD variation for the same phenological stages between years.
Morteza Akbarzadeh; Taghgi Mirhaji
Volume 13, Issue 3 , February 2006, Pages 222-235
Abstract
Study of vegetation changes of ungrazed rangelands is important. It is supposed that ungrazed areas tends toward climax and range condition to be improved. The major portion of our rangelands are laied in arid and semi-arid regions. For that precipitation is the major influential factor on vegetation ...
Read More
Study of vegetation changes of ungrazed rangelands is important. It is supposed that ungrazed areas tends toward climax and range condition to be improved. The major portion of our rangelands are laied in arid and semi-arid regions. For that precipitation is the major influential factor on vegetation changes. In dry years as rainfall decreases, the vegetation cover are damage. This study were conducted on Rudshur rangelands for nine years (1996-2004), with the aim of rainfall variation and ungrazed condition effects on vegetation changes. Plant parameters as canopy cover, density and seedling numbers were estimated on permanent plots each year. A dry period were started in 1997 in the region and continued for five years. Results showed, in a period of nine years, total canopy cover declined 40 percent. Decline of canopy cover varied from 26 to 95 percent for different species. Only canopy cover of the Poa sinaica increased about three times, due to earliest vegetative period in growing season. Decline in canopy cover was greatest in forbs, and grasses had lower decline. Regeneration was high in the rainy years and 81 percent of total seedlings belonged to grasses especially to Stipa hohenackeriana. Density of most species decreased in the study period especially in dry years.
Hosein Arzani; Khadijeh Mahdavi; Ali Nikkhah; Hosein Azarnivand
Volume 13, Issue 3 , February 2006, Pages 236-247
Abstract
Information on animal daily requirement and forage quality for determination of rangeland grazing capacity is an essential task for range management. Animal requirement depends on factors such as weight, age, physiological condition as well as forage quality. There are more than 27 sheep breeds with ...
Read More
Information on animal daily requirement and forage quality for determination of rangeland grazing capacity is an essential task for range management. Animal requirement depends on factors such as weight, age, physiological condition as well as forage quality. There are more than 27 sheep breeds with different body size in Iran. So it is not possible to represent a unique weight for animal unit in overall country. To overcome the problem live weight and daily requirement of each breed should be determined. In the present study, two herds of Dalagh sheep breed were selected with fifty head sheep in each including : fifteen head three years old ewes, fifteen head four years old ewes, ten head three months old lambs, ten head six months old lambs, five head three years old rams, five head four years old rams. They were weighed at three times (when grazing pasture, early and late winter in lowland). Average live weight of three and four year old ewes was considered as 51.75 kg. Equivalent animal unit for ram, three and six month lambs was obtained 1.37, 0.57 and 0.85 respectively. Animal requirement was determined based on forage quality in two phonological stages of vegetative and maturity. So, animal requirements were determined 1.2 and 1.53 kg dry matter per day at the times of vegetative and maturity stages respectively. Because of environmental condition and distance of watering point and sheep yard, metabolizable energy requirement per day was determined about 9/8 MJ. The SAS statistical software was used for data analysis according to factorial experiment in the form of completely randomized design. The result of analysis of variance showed herds, sex, age and location and also their interaction had significant effects on animal live weight (p<0.01).
Gholam reza Badjian; Dahlan Ismail; Ali akbar Mehrabi; Mohammad Shah vahid
Volume 13, Issue 3 , February 2006, Pages 248-264
Abstract
The Cost/ Benefit approach in taken to determine and compare the economic impacts of the main components of the Nomadic Livestock Production System in this studies before and after settlement the benefits and costs evaluation of livestock production systems are based on the impact of ecological changes ...
Read More
The Cost/ Benefit approach in taken to determine and compare the economic impacts of the main components of the Nomadic Livestock Production System in this studies before and after settlement the benefits and costs evaluation of livestock production systems are based on the impact of ecological changes in "with" and "without" project conditions. Transhumance living style of the nomads is called “without project” while “with project”, or the nomad settlement project, provides a life style of farming-animal husbandry dependent on highland range and cropland residues. The incremental benefits and costs during the performance of the projects are measured and the effects of discount rates in "with" and "without" project are evaluated. The results indicate that in the Bakkan region, with the crucial role of ecological impacts, discounting effects are not strong unless environmental benefits significantly outweigh the cost saving benefit. The sensitivity analysis of incremental net present value and benefit/cost ratio of the “with” project, with a longer sustainable life cycle, showed that “with” project is economically attractive and under these circumstances, could be considered as a viable alternative.
Mahmood Goudarzi; Mahdi Farahpour; Alireza Mosav
Volume 13, Issue 3 , February 2006, Pages 265-277
Abstract
In Iran, like many other developing countries, high population growth rate causes unfairly uses of natural resources and consequently land cover change. Therefore, detection of land cover (rangelands, irrigated and rainfed agricultural lands, urban areas…) changes can influence local planning ...
Read More
In Iran, like many other developing countries, high population growth rate causes unfairly uses of natural resources and consequently land cover change. Therefore, detection of land cover (rangelands, irrigated and rainfed agricultural lands, urban areas…) changes can influence local planning and natural resource management. Present study efforts to find a rapid and exact method of recognition different land covers using Landsat satellite data. Methods used in this research were image enhancement, false color composite (FCC), principal components analysis (PCA) and Image classification, i.e. normalized different vegetation index (NDVI) and supervised classification. A GIS environment, ILWIS software, was used. Results showed that irrigated agriculture, rainfed agriculture, rock out crop, rangeland classes (fair, moderate, poor condition) could be separated with overall accuracy of 89%.
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 ...
Read More
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.