hosein arzani; Javad Moetamedi; Firoozeh Moghimi nejad; reza siahmansour
Volume 22, Issue 4 , March 2015, , Pages 607-614
Abstract
In the present study, the forage quality of five range species including Astragalus remotijugus, Hordeum bulbosum, Onobrychis melanotricha, Phlomis persica, and Picris sterigosa were evaluated in 2010. At each phenological stage, three samples and for each sample, at least five species were cut randomly. ...
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In the present study, the forage quality of five range species including Astragalus remotijugus, Hordeum bulbosum, Onobrychis melanotricha, Phlomis persica, and Picris sterigosa were evaluated in 2010. At each phenological stage, three samples and for each sample, at least five species were cut randomly. Then samples were air-dried and grinded. The amount of crude protein (CP) and acid detergent fibers (ADF) was measured in laboratory then dry matter digestibility (DMD) and metabolism energy (ME) was evaluated by the proposed equations.Our results showed that the interaction effect of species and growth stage was significant for the forage quality traits studied (p<0.05) and the forage quality of the species study species varied at different growth stages. The highest amount of crud protein (18.17 %) was related to the vegetative growth stage of Phlomis persica, and the lowest amount was related to the seeding stage of Hordeum bulbosum. The highest level of digestibility (66.44 %) and metabolisable energy (9.30 MJ/KgDM) was measured for the vegetative growth stage of Onobrychis melanotricha, and the lowest amount of digestibility (42.65 %) and metabolisable energy (5.25 MJ/KgDM) was related to the seeding stage of Picris sterigosa. It is concluded that vegetative growth and flowering stages are able to provide the protein requirements and metabolizable energy for the animal unit; however, the final stages of growth is unable to meet the protein requirements, leading to reduced animal performance in the rangeland.. Therefore, the use of supplements in the final stage of growth is recommended for livestock maintenance and the economic efficiency of herd.
Morteza Hoseini |Tavasol; Hosein arzani; manoocher farajzadeh asl; Mohamad Jafari; sasan babayee kafaki; asghar kohandel
Volume 22, Issue 4 , March 2015, , Pages 615-624
Abstract
This research was aimed to monitor the vegetation changes in the rangelands of Alborz province during 2000-2011 using satellite images as well as determining its relationship with climatic factors including average rainfall, temperature, and relative humidity. According to the results, the highest NDVI ...
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This research was aimed to monitor the vegetation changes in the rangelands of Alborz province during 2000-2011 using satellite images as well as determining its relationship with climatic factors including average rainfall, temperature, and relative humidity. According to the results, the highest NDVI was recorded for Taleghan followed by Savojbolagh and Karaj, and then Eshtehard and Karaj with less significant difference. Based on the obtained model, the rainfall of November, December, January, February, and average annual rainfall had the most positive impact on the growth of range plants, while other factors including temperature and relative humidity had no significant relationship with the vegetation of the study period. According to the trend of vegetation changes, the amount of vegetation has been reduced after year 2000 and it has increased again in 2011.
sedighe zarekia; hosein arzani; mohamad jafari; noloufar zare
Volume 22, Issue 4 , March 2015, , Pages 745-756
Abstract
This research was aimed to investigate the effects of different grazing systems and intensities on soil and vegetation properties. Initially, the canopy cover percentage, density, and species height were measured using systematic random sampling. To investigate the changes in soil parameters in ...
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This research was aimed to investigate the effects of different grazing systems and intensities on soil and vegetation properties. Initially, the canopy cover percentage, density, and species height were measured using systematic random sampling. To investigate the changes in soil parameters in each area, 15 soil profiles were taken from 0 to 20 cm depth by systematic random sampling method. Data were analyzed in a completely randomized design. Also, continuous and heavy grazing during the year led to the removal of key species and changes in species composition. According to the results, continuous and heavy grazing resulted in increased soil potassium and phosphorous content. However, pH in none of the study sites was not statistically significant. Nitrogen and organic matter content did not differ significantly among the study sites. In addition, no grazing at exclosure increased the soil permeability. Although exclosure and rotation grazing at a moderate grazing intensity could desirably increase the vegetation cover, it had no significant effect on soil chemical properties. Generally, since arid regions are fragile ecosystems, the management of these areasshould include economic and biological considerations.
seyed akbar javadi; sonia khatibi baneh; hosein arzani; kazem saedi
Volume 22, Issue 4 , March 2015, , Pages 821-829
Abstract
This research was aimed to investigate the soil function indices in an exclosure region in comparison with non-exclosure. Then, using random plots as a control method, vegetation cover, stones and gravel, and litter were measured. Our results showed that the exclosure region (Saral Research Station) ...
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This research was aimed to investigate the soil function indices in an exclosure region in comparison with non-exclosure. Then, using random plots as a control method, vegetation cover, stones and gravel, and litter were measured. Our results showed that the exclosure region (Saral Research Station) had better condition in terms of function indices in comparison with non-exclosure regions, indicating the positive impact of no livestock grazing for a long time. Northern slope of the exclosure region and the southern slope of non-exclosure region were identified as the most stable (60.26) and unstable (52.8) in the study area. The highest infiltration was recorded for the southern slope of the exclosure region (58.7), and the northern slope of the exclosure region had the highest nutrient cycling (45.63). The western slope of the exclosure region represented the longest inter patch in the whole landscape and the northern slope of exclosure had the largest area and number of ecological patches. Considering the area and number of patches helps the range manager detect the effect of exterior and interior factors on rangeland easier. Overall, long-term exclosure in the Saral region could be mentioned as a suitable method to reduce the runoff, soil erosion, and sediment production.
Akbar Javadi; Hosein Arzani; Ali Salajeghe; Mahdi Farahpor; GHavam ... Zahedi
Volume 14, Issue 4 , February 2008, , Pages 513-523
Abstract
Proper use from water resources, especially in arid and semi arid rangeland are very important. Water is one of a valuable ecosystem component in rangeland management. In this study for surveying of water suitability, tree models including quality model, quantity and distance model made final model. ...
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Proper use from water resources, especially in arid and semi arid rangeland are very important. Water is one of a valuable ecosystem component in rangeland management. In this study for surveying of water suitability, tree models including quality model, quantity and distance model made final model. FAO (1991) method (recommended for land capability evaluation) was used for suitability classification. The study was conducted in Halvan region is located in Yazd province. According to the results, water resources distance and accessibility to water is the most declining factor for suitability. Quality factor is a limiting factor in part of the study area, too. Based up on, areas more than 15km far from water point are not suitable, but less than 6km are very suitable. Proper distribution of water resources increases water suitability and cause better and monotonous utilization of rageland.
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.
Hosein Gharadaghi; Hosein Arzani; Hasan Ebrahimzadeh; Mohammad reza Ghnnadha; Naser Baghestani
Volume 14, Issue 1 , January 2007, , Pages 19-32
Abstract
Rangelands are one of the important natural ecosystems in our country that were deteriorated during recent decades because of many causes especially earlier and intensive grazing. Grazing management need to determine beginning of grazing season and intensity in rangelands. It is very important to know ...
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Rangelands are one of the important natural ecosystems in our country that were deteriorated during recent decades because of many causes especially earlier and intensive grazing. Grazing management need to determine beginning of grazing season and intensity in rangelands. It is very important to know much about physiological and phenological status of rangeland species. Total nonstructural carbohydrates (TNC) and their changes during seasonal growth is one of the important physiological parameter in perennial plants. Also these reserves are primary source of energy in respiration, growth and survival of perennial plants during their quiescence and growth season and regrowth after grazing or cutting. In this research seasonal changes of TNC reserves in three perennial and desirable grass species(Bromus tomentellus, Festuca ovina, Dactylis glomerata) were studied in Polor summer rangelands(altitude, 2600m; annual precipitation, 535mm; with cold mountain climatic) at the north of Tehran province. Samples were collected in ten stages of plants phenology stages with three replications from above and underground matter (canopy and roots). Samples were oven dried at 70◦C during 48 houres. TNC concentration were measured by phenol-solpheric method (mg per gr dry matter). Data of all attributes were analyzed in the frame of rondomized compeletly block design by using Minitab software, and ANOVA one and two ways. Seasonal changes of TNC reserves in any of studied species and also their root and canopy were shown in annual curves. The results indicated that all species have distinct seasonal changes and they had the lowest TNC reserves at early spring and end of the seasonal growth and then increased. The results showed significant differences in TNC reserves between phenology Stages in root and canopy during seasonal growth (P= 0.05 & 0.01) and all species had higher amount of TNC reserves in root than canopy (P=0.01). The rate of TNC restoration was different between studied species. These differences were related to phenology and seasonal growth along. So in this area Dactylis glomerata is more sensitive to grazing and Bromus tomentellus conversely is more resistant to grazing. At the end we concluded that critical period for all species in relate of their TNC reserves is from starting growth in early spring till early May and at the end of seasonal growth, mid August. Beginning of grazing season from late may until early August is recommended for this area.
Hosein Arzani; Mahdi Abedi; Ehsan Shahriyari; Mahdi Ghorbani
Volume 14, Issue 1 , January 2007, , Pages 68-79
Abstract
Management activities like grazing intensity and land cultivation effects rangelands characteristic. For sustainable utilization of rangeland, information of changes is required. Soil surface indicators and functional attributes help to judging about management impact. So for investigation on these activities ...
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Management activities like grazing intensity and land cultivation effects rangelands characteristic. For sustainable utilization of rangeland, information of changes is required. Soil surface indicators and functional attributes help to judging about management impact. So for investigation on these activities effects in semi arid rangeland, one vegetation community was selected in Taleghan region. Five cases including: three grazing intensities (heavy, moderate and low), recently cultivated and relict areas that were cultivated in last two decades were assessed. Landscape function analysis (LFA) method was used to evaluate management effects on soil surface characteristics and rangeland functional attributes. In this method for determination of three functional attributes of stability, infiltration and nutrient cycle, 11 soil surface indicators were considered. They are soil surface cover (soil protection from erosion), perennial canopy/basal cover, litter (cover, origin, degree of decomposition), cryptogam cover, crust brokenness, type and severity of erosion, deposited material, soil surface roughness, soil surface resistance to distribution, slake test (soil stability test) and texture. Based on the results, land cultivation reduced functional attributes. By increasing grazing intensity, palatable species are eliminated and in heavy grazing area the dominated vegetation cover are annuals. Vegetation and soil surface layer degradation increased soil erosion, created gully and reduced functional attributes. In relict area because of re-establishing homogenous annuals, soil indicators and functional attribute were improved.
Syed Ata Rezaei; Hosein Arzani
Volume 14, Issue 2 , January 2007, , Pages 232-248
Abstract
In this research, to identify the functioning of the soil-landscape system and its effects on plant growth for native rangeland, we investigated the relationships between soil properties and Landscape Function Analysis (LFA) indices and between plant growth characteristics and LFA indices. The results ...
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In this research, to identify the functioning of the soil-landscape system and its effects on plant growth for native rangeland, we investigated the relationships between soil properties and Landscape Function Analysis (LFA) indices and between plant growth characteristics and LFA indices. The results interpreted based on statistical analysis and expert knowledge. This research was carried out for a semi-arid rangeland in the Lar aquifer in Iran. Land stratification allowed the study area to be subdivided into Land Units, according to specified criteria including landform attributes (slope, aspect, and altitude), and vegetation type. A factorial model on the basis of a completely randomized design was used to analyze the data collected from 236 land units. The landscape function indices including nutrient cycling index, Infiltration index, Stability index, and Landscape organization index were derived by various integrations of soil surface attributes. Landscape attributes differed from one another in their effects on the different landscape function indices. Increasing slope gradient significantly reduced all landscape function indices as well as soil organic carbon and total nitrogen percentages. Slope class exhibited highly significant interaction effects with vegetation type factors for stability, nutrient cycling, and landscape organization indices. Aspect did not significantly affect stability, infiltration, and landscape organization indices, but significantly affected the nutrient cycling index. The Duncan test indicated that north aspect (shady side) had the highest mean value (28.42) and south aspect the lowest mean value (25.57) for nutrient cycling index. These results are consistent with the effects of aspect on total soil nitrogen and soil organic carbon percentage for which the north aspect had the highest values. The values declined in the sequence east, west, and south aspects respectively. This research indicates that the nature of native rangeland plant communities and their measures of production are closely related to nutrient cycling index.
Ali Ehsani; Hosein Arzani; Mahdi Farahpoor; Hasan Ahmadi; Mohammad Jafari; Adel Jalili; Hamid Reza Mirdavodi; Hamid reza Abbasi; Mojgan Azimi
Volume 14, Issue 2 , January 2007, , Pages 249-260
Abstract
The effects of climatic factors on four dominant range land species of Markazi province, Iran, were studied. Species were Artemisia sieberi, Salsola rigida, Noaea mucronata, Stipa barbata and were monitored from 1998 to 2005. Site is located in steppe lands and called Nemati range, Akhtarabad of Saveh. ...
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The effects of climatic factors on four dominant range land species of Markazi province, Iran, were studied. Species were Artemisia sieberi, Salsola rigida, Noaea mucronata, Stipa barbata and were monitored from 1998 to 2005. Site is located in steppe lands and called Nemati range, Akhtarabad of Saveh. Climatic factors were annual rainfall, rainfall of grazing season plus rainfall of previous year, temperature, solar radiation and wind velocity. Among the main indicators, as results shows, growing season plus previous rainfalls is the most effective indicator on forage production with high and significant correlation. Total yield have positive and significant correlation with growing season rainfall and previous rainfall as well as production of Artemisia sieberi, Salsola rigida. Soil and water regime in dry and semi-dry areas, in growing season, is in a way that plants are dependent on stored moisture. Shrubs, with their deep roots, are more capable of using this moisture. Therefore stored moisture could be known as an indicator of rain quantity. Result of this research showed that rainfall indicator in growing season and previous season is a variable that plays fundamental rule in production, showing a linear relationship. Negative correlation was shown between number of sunny days, total yield and yield of two species, Salsola rigida and Artemisia sieberi.
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 ...
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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%.
Jalal Abdollahi; Hosein Arzani; Naser Baghestani; Fakhr.... MirAskarshahi
Volume 13, Issue 2 , February 2006, , Pages 74-81
Abstract
An optimal planning system for managing the range and maintaining it’s vegetation is highly influenced by the humidity and rainfall of the range. In this research, the reactions of the seidlitzia rosmarinous species to the fluctuation of precipitation and under ground water were studied at Chah-Afzal ...
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An optimal planning system for managing the range and maintaining it’s vegetation is highly influenced by the humidity and rainfall of the range. In this research, the reactions of the seidlitzia rosmarinous species to the fluctuation of precipitation and under ground water were studied at Chah-Afzal in Ardakan-Yazd. Regarding the amount of collecting data after five years, by applying Minitab software, using linear regression, an equation between the amount of the production and precipitation was obtained with a high correlation coefficient (r=0.93). The results showed that the variation of the plant production was due to the fluctuation of the annual precipitation. Moreover, result of another analysis was demonstrated a lack of agreement between the cover and density of the se.rosmarinous species with the amount of precipitation. In addition, the results state that the downward trend in the percentage of canopy cover and the density of the se.rosmarinous species in the region are highly influenced (r=0.94 and r=0.99 respectively) by the discharge of ground water table. Thus, the gradual decrease of this source in the coming years might bring out negative effects on the cover, density and finally on the condition of the range in Chah-Afzal. Also, Interaction between the effect of ground water table changes on the amount of forage production was not significant.
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 ...
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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).
Hosein Arzani; Mahdi Abedi
Volume 13, Issue 2 , February 2006, , Pages 145-161
Abstract
Rangeland as a dynamic ecosystem changes by accruing abundance and if cross the rangeland health threshold may be disturbed. By determination rangeland health attributes, we could judge about management practices effects. In this research for determination three attributes (soil and site stability, hydrologic ...
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Rangeland as a dynamic ecosystem changes by accruing abundance and if cross the rangeland health threshold may be disturbed. By determination rangeland health attributes, we could judge about management practices effects. In this research for determination three attributes (soil and site stability, hydrologic function and biotic integrity) , seventeen indicators used include rill, water flow pattern, pedestals and terracettes, bare ground, gullies, wind scour and depositional area, litter movement, soil resistance to erosion, soil surface loss or degradation, plant composition, soil compaction, plant functional/structural groups, plant mortality, litter amount, annual production, invasive plant and reproductive capability. This method was conducted in six steps. to test this new concept in arid and semi arid zone , thus by using vegetation and soil studies in Orazan (Taleghan) region and Zarand Saveh, selected five treatment included: three grazing intensity and two cultured area and then modified indicators table categorized under three ecosystem attributes in five classes. Because of grazing and cultured treatment rangeland health attributes reduced and showed significant differences by references area. Most treatment crossed the rangeland health threshold. By increasing grazing intensity stractural plant characterestics and soil characteristic beetwin plants disturbed.inreliced cultivated area soil stability and hydrologic function attributes modified but plants health attribute in comperation with references area have a little change. Results showed that soil surface resistance decrease and water flow pattern degradation are the most important causes in rangeland health decrease.