Hasan Barati; ali Tavili; hosein Arzani; farhang Ghasriani
Volume 22, Issue 3 , November 2015, , Pages 436-446
Anvar Sanaie; Hossein Arzani; Ali Tavili; Mehdi Farahpour
Volume 22, Issue 2 , August 2015, , Pages 275-288
Abstract
This study aimed to evaluate the range suitability for sheep grazing according to the Manual of Suitability for Sheep Grazing instructions in the rangelands of central Taleghan and comparison with the FAO guidelines (1991). Accordingly, the final model of range suitability was determined from combining ...
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This study aimed to evaluate the range suitability for sheep grazing according to the Manual of Suitability for Sheep Grazing instructions in the rangelands of central Taleghan and comparison with the FAO guidelines (1991). Accordingly, the final model of range suitability was determined from combining three criteria of vegetation, water resources and soil erosion. Sampling was conducted in the key area of vegetation types through random-systematic method with four transects of 200 meters and 40 plots of one square meter and in each plot, the list of species, canopy cover percentage, and species composition as well as production were harvested and calculated. For this purpose, the results of the proposed instructions were compared with the results of the FAO model (1991) by non-parametric Wilcoxon test. Our results clearly showed that the lack of available forage, low allowable use, erosion and the formation sensitive to erosion (Marl), poor condition and negative trend in some vegetation types as well as steep and mountainous regions were among the factors, limiting range suitability for sheep grazing. The final results of sheep grazing model showed that no vegetation type was placed in S1 and N classes, and most of the vegetation types of the study area was in S2 range suitability class, so that from 25576.9 ha of the rangelands studied, 87.25% was in S2 class and 12.75% was in S3class. According to the results of comparison of the two methods for determining range suitability, no significant differences were found (P <0.01).
Mojtabah Akhavan Armaki; Hosein Azarnivand; Mohammad hasan Asareh; Ali ashraf Jafari; Ali Tavili
Volume 18, Issue 4 , September 2012, , Pages 558-568
Abstract
Environmental stress especially water deficiency (drought) is of the most important factors in arid and semi arid regions of Iran that hugely affects plant growth especially in germination and emergence stages. To find the effects of water stress on germination properties and early growth characteristics ...
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Environmental stress especially water deficiency (drought) is of the most important factors in arid and semi arid regions of Iran that hugely affects plant growth especially in germination and emergence stages. To find the effects of water stress on germination properties and early growth characteristics of three Bromus species (B. tomentellus, B. inermis, B. persicu), a Factorial experiment based on Completely Randomized Design with four replications was conducted. Water stress treatments included -3, -6 and -9 bars, also distilled water was considered as control. Germination percentage, root length, shoot length, seedling length, root to shoot ratio, seedling dry weight, seedling fresh weight, dry to fresh weight ratio, germination rate and seed vigor were examined as germination and early growth properties of understudied species. The results showed that increase of drought stress, especially when changing from -3 to -6 bars, significantly reduced all attributes. Seedling length and seed vigor showed more decrease. Among the species, B. tomentellus showed higher germination compared to the other species. It was cleared that -6 and -9 bars potentials could be considered as favorable water stress levels to evaluate the ability of the mentioned species for germinating under drought conditions.
Reza Yari; Ali Tavili; Salman Zare
Volume 18, Issue 4 , September 2012, , Pages 624-636
Abstract
Management activities like crescent intake and enclosure affect the soil surface indicators and rangeland functional attributes. To have a continuous and sustainable utilization of rangelands these changes must be recognized and managed. Indicators of soil surface characteristics and rangeland functional ...
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Management activities like crescent intake and enclosure affect the soil surface indicators and rangeland functional attributes. To have a continuous and sustainable utilization of rangelands these changes must be recognized and managed. Indicators of soil surface characteristics and rangeland functional attributes assist researchers in judging the effects of their applied management activities. The aim of this study is to investigate the effects of management activities like crescent intake and enclosure on soil surface indicators and rangeland functional attributes. For this purpose, three regions including freed enclosure, enclosure and crescent intake were selected and the effect of any aforementioned activities on soil surface characteristics and rangeland functional attributes were investigated by using Landscape Functional Analysis (LFA) method. In this method, for determination of three functional attributes (stability, infiltration and nutrient cycle) 11 soil surface indicators were applied as follows: ground cover, litter cover, litter (degree of decomposition), cryptogam cover, soil surface resistance to distribution, eroded materials, erosion features, soil microtopograghy, soil surface nature, slake test and soil texture. Data analysis was performed with SPSS software, Kruskal-Wallis nonparametric test and a Duncan multiple range test. According to the results, the indicators and functional characteristics of the rangeland have been changed due to the management activities. As significant differences were found among all 11 soil surface indicators except erosion feature and cryptogam cover in three studied regions (P<0.05). Also significant differences were found among three rangeland functional attributes in three study areas. Our results indicate that crescent intake and enclosure could improve rangeland functional attributes.
Hosein Azarnivand; Ali Tavili; Ali Sadeghi Sangdehi; Mohammad Jafari; Mohamad ali Zare Chahouki
Volume 18, Issue 3 , September 2011, , Pages 372-383
Abstract
Understanding ecological needs of range species is of utmost importance for range managers in conservation and utilization of rangeland ecosystems. The current research was conducted to find out ecological characteristics of Astragalus squarrosus in Kashan. In each study area, soil sampling was performed ...
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Understanding ecological needs of range species is of utmost importance for range managers in conservation and utilization of rangeland ecosystems. The current research was conducted to find out ecological characteristics of Astragalus squarrosus in Kashan. In each study area, soil sampling was performed at depths of 0-30 and 30-60 cm along four transects. Vegetation sampling was done in three phonological stages of vegetative growth, flowering and seed ripening. Soil studies of the mentioned species showed that it mainly grew in soils with sandy loam to loamy sand textures, EC of 0/4 -4/2 ds/m and pH of 7/49 -8/17. According to the results of the vegetation studies, average of the current yield was 78/3 kg/ha and 1322/9 species per hectare was estimated as average of the density of A. squarrosus. Forage quality analysis at three phonological stages of vegetative growth, flowering and seed ripening showed that the amount of CP and OC were reduced up to 3.6% and 0/82 respectively. Decrease of DMD and ME and increase of ADF values at seed ripening stage was associated with a considerable decrease in palatability and subsequently forage quality.
fahimeh Arab; Ali- Ashraf Jafari; Mohammad- Hassan Assareh; Mohammad Jafari; Ali Tavili
Volume 18, Issue 1 , May 2011, , Pages 17-31
Abstract
Agropyron deserterum andAg. elongatum species have a high value for both fresh and dry forage and because of high production and top acceptance by livestock they have specific value in the beginning of the growth season for livestock grazing. This research was conducted to study the effects of ...
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Agropyron deserterum andAg. elongatum species have a high value for both fresh and dry forage and because of high production and top acceptance by livestock they have specific value in the beginning of the growth season for livestock grazing. This research was conducted to study the effects of salinity stress on the mentioned species in germination and vegetative growth stages. A completely randomized design including five levels of 0, 100, 200, 300 and 400 mM NaCl and CaCl2 with 4 replications was used. Seeds were sown in laboratory and germination percentage, germination velocity, vigor index, plumule and radicle length and seedling dry weight were calculated. In greenhouse condition, shoot and root length, seedling dry weight, dry weight to fresh weight ratio, leaf area and specific leaf area were measured. According to the results, in both studied species germination percentage, plumule and radicle length, seedling dry weight, leaf area and specific leaf area were reduced with increase of salinity. The results showed significant differences between two species for germination percentage and germination velocity (P≤0.01). In both germination and vegetative growth stages, Ag.elongatum was more salt tolerant than Ag.desertorum. The results indicated that Ag.elongatum was more salt tolerant species than Ag.desertorum and it can be recommended for cultivation in moderate saline rangelands.
Gholam reza Zehtabian; Mehrnush Ghadimi; Ali Tavili; Jamal Bakhshi
Volume 17, Issue 3 , October 2010, , Pages 353-361
Abstract
This research was performed to investigate the relationship between environmental factors including water and plant composition. In other words, determining the most effective factors in distribution of vegetation types in Arak playa was the main aim of this study. To achieve this goal, the initial map ...
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This research was performed to investigate the relationship between environmental factors including water and plant composition. In other words, determining the most effective factors in distribution of vegetation types in Arak playa was the main aim of this study. To achieve this goal, the initial map of vegetation was provided and afterward water and vegetation sampling was done. Water parameters including K, Na, CL, Mg, %Na (exchangeable sodium percentage), Th, SAR, Co3, Hco3, So4, TDS (total hardness), EC, pH, and anions (sulfates, bicarbonates and chlorates) were measured. Multivariate data analysis techniques including principal component analysis (PCA) and canonical correspondence analysis (CCA) were used to analyze the collected data. The results showed that vegetation distribution pattern was mainly related to water characteristics such as Mg, TDS, Cl, anion, EC and Th. it can be concluded that according to habitat conditions, ecological needs and tolerance range of each plant species have significant relationship with water properties.
Jamal Imani; Ali Tavili; Esaa Bandak; Bahram Gholinejad
Volume 17, Issue 3 , October 2010, , Pages 393-401
Abstract
Analysis of vegetation is one of the important factors in appropriate management of rangelands. The current research was conducted to evaluate canopy cover percentage, forage production, and species density in four areas including reference area, personal rangeland, key area and critical area in the ...
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Analysis of vegetation is one of the important factors in appropriate management of rangelands. The current research was conducted to evaluate canopy cover percentage, forage production, and species density in four areas including reference area, personal rangeland, key area and critical area in the region of village. In each area, 5 transects were established on which 10 quadrate 1 m were used with regard to the plant type and distribution of species. The lengths of each transect and the distance between them were determined 100 m and 20 m respectively according to the species density and distribution. Canopy cover percentage, forage production and species density were recorded in all quadrates. Clipping and weighing method was used to estimate forage production. Data analysis was performed using one way ANOVA and Duncan test. Results indicated that there was significant difference in canopy cover percentage (p≤ 0/1), forage production (p≤ 0/05) and species density (p≤ 0/01) among 4 studied areas. The result showed that with moving from reference to critical area, canopy cover percentage, forage production and species density dramatically decreased as palatable species (class I), average palatable species and non palatable and invasive species had the most canopy cover percentage, forage production and density respectively in reference area, personal rangeland and common area between village and critical area. Perennials and palatable grasses such as Bromus tomentellus and Hordeum bolbosum had the highest canopy cover percentage, forage production and density in reference area. With a gradual increase in grazing intensity, percentage of palatable species decreased while non palatable species like Boisseria squarrosa and Centaurea virgata increased. This research revealed that heavy grazing jeopardized the sustainability of the rangeland ecosystem by creating unfavorable changes in vegetation characteristics.
Ali Tavili; Salman Zare; Reza Yari
Volume 17, Issue 3 , October 2010, , Pages 466-475
Abstract
Nowadays, with regard to the global view of desert issue and necessity of using adaptable species in combat desertification, it is urgent to identify and remove the constraints of their production and establishment. Ammodendron persicum is one of the important and compatible species in desert ecosystems. ...
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Nowadays, with regard to the global view of desert issue and necessity of using adaptable species in combat desertification, it is urgent to identify and remove the constraints of their production and establishment. Ammodendron persicum is one of the important and compatible species in desert ecosystems. The current research was carried out to investigate the effect of different treatments on seed dormancy breaking and germinationstimulation ofAmmodendron persicum in order to determine the most effective treatment in enhancing of germination and primary growth of seedlings .The experiment was done in a Randomize Complete Block Design (RCBD) with 8 treatments and 4 replications. Different treatments were applied including scarification plus sulphuric acid (H2SO4 98%) for 10 and 15 minutes, scarification with sandy paper, scarification plus putting the seeds in hot water for 10 and 15 minutes, KNO3 (0.1 and 0.2 %), a complex treatment of scarification and KNO3 (0.1 and 0.2%) and distilled water as control treatment .To analyze the data, ANOVA was used and Duncan test was applied to compare the means. The result showed that scarification with sandy paper had the highest effect onseed dormancy breaking and seed germination stimulation of A. persicum as germination percentage increased from 3% in distilled water to 68% in scarification treatment.
Morteza Saberi; Ali Tavili
Volume 17, Issue 1 , September 2010, , Pages 51-60
Abstract
Puccinellia distans is a perennial range species from Poaceae family. The current research was performed to evaluate different priming treatments effect on improving seed germination in P.distans. For this purpose a factorial experiment with a completely randomized design in four replications with 3 ...
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Puccinellia distans is a perennial range species from Poaceae family. The current research was performed to evaluate different priming treatments effect on improving seed germination in P.distans. For this purpose a factorial experiment with a completely randomized design in four replications with 3 priming treatments (9 levels) was conducted. Treatments included salicylic acid (100, 200 and 300 mg/l), gibberlic acid (125, 250 and 500 ppm) and ascorbic acid (100 and 300 mg/l). The time of each of mentioned treatments was considered 10, 24 and 8 hours, respectively. Distilled water was used as control treatment. Evaluated germination characteristics were percentage and rate of germination. Results indicated that priming application has had considerable influences on seed germination so that there are significant differences between obtained results. Priming with salicylic acid (at 300 mg/l level) had the highest effect on germination.It increased germination percentage up to 40% and germination rate up to 1.8 seed/day compared to control treatment.
Jamal Emani; Ali Tavili; Essa Bandak; Mohammad Khosravi
Volume 17, Issue 2 , September 2010, , Pages 234-242
Abstract
Flood water spreading projections have been done with many objectives. One of these objectives is increasing vegetation cover. Flood water spreading leads to the increasing of soil moisture and as a result increasing forage production. In this study the effects of flood spreading are evaluated. This ...
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Flood water spreading projections have been done with many objectives. One of these objectives is increasing vegetation cover. Flood water spreading leads to the increasing of soil moisture and as a result increasing forage production. In this study the effects of flood spreading are evaluated. This assessment is done in aquifer of Mayhem district of Ghorveh state. In each rainfall that results into flood, 6 areas are flooded and 2 areas are not flooded. Therefore, 6 areas considered as the flood water spreading and 2 areas considered as the control site. The samplings of vegetation properties were performed in these eight areas. For this purpose, in each district, 5 transects each with a length of 100 m with 10 m interval from each other were situated and along each transect, 10 quadrates with an area of 1m were established. In each area, the characteristics of canopy cover percentage, forage production and species density were recorded. Analysis of data was performed using of un-paired T-test. Obtained results from T-test indicated that there is significant difference between canopy cover percentage (p≤ 0/1) and forage production (p≤ 0/05) while no significant difference was observed for species density in flooded and non-flooded areas. The results showed that the canopy cover increased from 41/91 percent in the control site to 62/18 percent in the flood spreading area. The forage production increased from 467/17 kg/ha in the control site to 632/17 kg/ha in the flood spreading area. Also the species density increased from 1/18 in the control site to 1/59 in the flood spreading area. Some of the plant species that are in the III classes from palatability aspect, decreased in the flood spreading area rather than control site.
Zainab Nurikiya; Akbar Javadi; Akbar Fakhireh; Ali Tavili; Mohammad ali Zare chahouki; Hamid reza Abbasi
Volume 16, Issue 4 , January 2010, , Pages 574-585
Abstract
The purpose of this research was to compare the amount of N, P and K in the soil under three rangeland species i.e. Agropyron tauri, Astragalus ammodendron and Bromus tomentellus and (with) the soil properties of the control area. After identifying the habitats (sites) of the mentioned species, soil ...
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The purpose of this research was to compare the amount of N, P and K in the soil under three rangeland species i.e. Agropyron tauri, Astragalus ammodendron and Bromus tomentellus and (with) the soil properties of the control area. After identifying the habitats (sites) of the mentioned species, soil sampling was done in all key areas at the end of the growing season based upon randomized systematic method. In order to study the features of the mentioned species, 10 plots (1 m2) were established along 4 transects.Soil sampling was carried out in the beginning and in the end of all transects from 0-10 and 10-40 cm soil depths. Soil sampling was also done in the control area and then N, P and K were measured. All data were analyzed and compared by T test. The results indicate that the amount of N, P and K in the first soil depth beneath Agropyron tauri is more than that in Astragalus ammodendron and Bromus tomentellus. In most cases the amount of N and K in the soil beneath (under) the species are more than that in the control area which indicates the increase of fertility in the soil beneath the species in comparison to the control area and it can be due to the litter fall or intensified biological activities of the organisms.
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.