Mahdokht Allahmoradi; Hosein Arzani; Ali Tavili
Volume 27, Issue 1 , April 2020, , Pages 13-23
Abstract
Determining grazing capacity of rangelands is one of the main factors in range management so that, regarding this important factor, is one the main causes of range degradation in Iran. Middle Taleghan rangelands have utilized for many years thus, there aren’t preserved from degradation. The aim ...
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Determining grazing capacity of rangelands is one of the main factors in range management so that, regarding this important factor, is one the main causes of range degradation in Iran. Middle Taleghan rangelands have utilized for many years thus, there aren’t preserved from degradation. The aim of this research was to determine the short term grazing capacity of these rangelands to show factors affecting grazing capacity and both preserve and improve the condition of them. During the field work was done in June 2013, sampling performed by random- systematic method using four 150 meters transects and 10 plots along each one randomly and current forage production was harvested in separation of each species form all three palatability classes. Then proper use factor was determined. Finally, short term grazing capacity was calculated through the computing daily requirement energy method and attending to forage quality for each type. The results are shown that grazing capacity range from 0 to 1534 Fashandi race adult sheeps for grazing period. Least required area for a sheep grazing range from 1.92 to 8.63 hectares for grazing period. Grazing capacity for all of studied rangelands is equal to 6802 Fashandi race adult sheep by 60.7 kg weight and least required area for a sheep grazing is 3.76 hectares in average, Whereas the actual grazing capacity in these rangeland is mostly 159 Fashandi race adult sheeps per hectar for good condition ranges ang 19 for poor condition ranges. So, For calculating grazing capacity it is also necessary to consider palatability, proper use factor, forage quality, animal weight and its daily requirement and its movment rate in addition to rangeland yield. Thus, current research is emphasizing on to pay attention toward all effective factors in evaluating rangeland grazing capacity.
Javad Moetamedi; Hosein Arzani; Mohammad Jafari; Mehdi Farahpour; Mohammad Ali Zarechahouki
Volume 26, Issue 1 , June 2019, , Pages 241-259
Abstract
The calculation of the grazing capacity requires the consideration of factors affecting it. Due to the effective factors, the long-term grazing capacity model was designed, and then the capacity of the rangelands was calculated. Grazing capacity was calculated by the proposed ...
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The calculation of the grazing capacity requires the consideration of factors affecting it. Due to the effective factors, the long-term grazing capacity model was designed, and then the capacity of the rangelands was calculated. Grazing capacity was calculated by the proposed model in four steps including estimating the average good production, calculation of available metabolic energy, the daily requirement of the animal unit and grazing capacity. Due to the drought condition of habitats and fluctuation of forage production in different years, one cannot calculate grazing capacity with once production measurement for the long-term. Hence, the average good production of habitats was determined and based on that, long-term grazing capacity was calculated. The average good production of Golestan Kouh, Vardast, and Pashmakan habitats in the statistical period of 6-7 years was estimated to be 425, 233.8 and 343.3 kg/ha, which are related to normal years in terms of rainfall. The grazing capacity of habitats in a quarterly period of four months was calculated to be 0.8, 0.3 and 0.5 animal unit per hectare so that if there is a drought for 12 consecutive months, there will be no damage to vegetation. Meanwhile, there is not much damage to the beneficiary and he will not have to sell too much of his livestock. The area needed for grazing of an animal unit in the rangelands was suggested to be 1.3, 3.3 and 2 hectare. This amount is recommended to be one hectare for a 30-year period based on a common method in range management plans. This indicates the need to pay attention to the factors affecting the grazing capacity and emphasizes the application of the proposed model in order to calculate the rangeland capacity.
farhang ghasriani; mina bayat; mirtaher ghaemi; hasan yeganeh
Volume 24, Issue 1 , May 2017, , Pages 142-151
Abstract
This research was aimed to investigate the effects of different harvesting intensities on forage yield and vitality of Aeluropus littoralis, as a key and important range species in the Tez Kharab rangelands, Urmia, Iran. The study was conducted in the rangelands around Urmia Lake and a 0.5-ha exclosure ...
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This research was aimed to investigate the effects of different harvesting intensities on forage yield and vitality of Aeluropus littoralis, as a key and important range species in the Tez Kharab rangelands, Urmia, Iran. The study was conducted in the rangelands around Urmia Lake and a 0.5-ha exclosure was selected and fenced in the first year of the study. The treatments consisted of four harvesting intensities including 0%, 25%, 50%, and 75%. Harvesting treatments were applied for four years during the growing season and at the start of livestock grazing. The harvested forage was air-dried and weighed to calculate the forage yield. In addition, the remaining yield of control and harvesting treatments were cut, dried, and weighed. Data were analyzed using a split-plot design in time. Finally, the effects of changes in phenological characteristics, forage yield, plant vitality and mortality were investigated. The effects of year and harvesting intensities as well as interaction effects of year and harvesting intensity were significant on forage yield (P<0.05). This indicates that forage yield differs in different years depending on climate conditions. Our results clearly showed that increased utilization led to reduced plant vitality. According to the obtained results, a harvesting intensity of 50% could be recommended as an optimal allowable use of forage with the least negative impacts on plant vitality.
Muhammad Reza Shooshtari; Farhang GHasryani; Amir ghorbankhani
Volume 23, Issue 4 , March 2017, , Pages 810-822
Abstract
Rangelands cover about half of Iran’s territory with unique ecological characteristics. Understanding these characteristics is an essential need for any management in these arenas. In this regard, the present study was carried out to evaluate the intensity of grazing on vegetative and reproductive ...
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Rangelands cover about half of Iran’s territory with unique ecological characteristics. Understanding these characteristics is an essential need for any management in these arenas. In this regard, the present study was carried out to evaluate the intensity of grazing on vegetative and reproductive characteristics of Bromus tomentellus, as a key species in the rangelands of Gavanban in Kermanshah province during four years. At first, a reference area of one hectare was selected and fenced. Simulation method was used in this study. Treatments included four harvesting intensities of 25, 50 and 75% and control on Bromus tomentellus. In each treatment, 40 individuals of species were selected. The effect of exploitation on phenological characteristics such as height, number of flowering stems, vigor, vitality, collar area, forage production and other characteristics were evaluated. All data were analyzed using combined analysis of variance in a completely randomized design. Results showed that production of Bromus tomentellus did not differ statistically in response to different harvesting intensities, and up to 75 percent of the species could be harvested; however, in some cases, morphological traits were affected, leading to decreased number of flowering stems, and increased collar diameter over the years. Also, it did not have any significant effect on height and vitality. In other words, the regeneration of species harvested decreased (due to reduction in the number of flowering stems). However, 75% harvesting intensity caused increased collar area.
Javad Moetamedi; saeedeh Toupchizadegan
Volume 23, Issue 3 , January 2017, , Pages 527-542
Abstract
Determining the allowable use is one of the basic requirements to calculate the grazing capacity in range management plans. In this study, initially, the range condition and trend of vegetation types and the suitability class of soil susceptibility to erosion were determined. Then, the allowable use ...
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Determining the allowable use is one of the basic requirements to calculate the grazing capacity in range management plans. In this study, initially, the range condition and trend of vegetation types and the suitability class of soil susceptibility to erosion were determined. Then, the allowable use was determined for each vegetation type regarding the mentioned indices and that the allowable use in each climate region is recommended differently to maintain rangeland health. The maximum allowable use for the study rangelands, representing mountainous semi-steppe, was calculated to be 40%. The allowable use of other vegetation types was determined regarding the limitations of indices. According to the results, the allowable use was calculated to be 40%, 30%, 25%, and 15% for 21.4%, 13.6%, 19.3%, and 27.6% of the study rangelands, respectively. Around 18.1% of the study rangelands were classified as non-utilizable due to the poor range condition, negative trend and the soil susceptible to erosion. In most areas, poor range condition and negative trend acted as a limiting factor and led to a low estimate of allowable use. Therefore, care must be taken in selecting the indices affecting the allowable use of range habitats and in addition to plant health, range condition and trend as well as ecosystem health should be considered.
Ghader Karimi; Hasan Yeghaneh; Hasan Barati; Farhang Ghasriani
Volume 21, Issue 4 , March 2015, , Pages 631-642
Abstract
A proper utilization of rangelands could result in preventing degradation, maintaining desirable species and improving range condition, leading to longterm and economic production. This research was aimed to investigate the allowable use of Stipa hohenckeriana in Kordan rangelands. In this study, a reference ...
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A proper utilization of rangelands could result in preventing degradation, maintaining desirable species and improving range condition, leading to longterm and economic production. This research was aimed to investigate the allowable use of Stipa hohenckeriana in Kordan rangelands. In this study, a reference area of one hectare was selected and fenced in the first year of the study. Treatments included four harvesting intensities of 25, 50 and 75% and 0 (control group). Finally, data were analyzed using split plot design in time with 10 replications for each treatment. Data analysis was performed by SAS software. Results showed that the effects of harvesting intensity, different years and their interactions on the forage production were significant at 1% level of probability, indicating that in different years, production rate varied with varying climate conditions. According to the results, an allowable use of 25% is recommended for Stipa hohenckeriana in the study area. The recommended allowable use can be used in determining the allowable use for the study area and areas of similar climate, along with information from other plants.
Farhang Ghasryani; Mina Bayat; Afsaneh Jabarzare; Mirtaher Ghaemi
Volume 21, Issue 3 , December 2014, , Pages 507-517
Abstract
The calculation of carrying capacity and allowable use of key species is necessary for sustainable range management. Vegetation degradation and soil and water loss can be prevented in the rangeland through calculating the actual carrying capacity. The aim of this research was to evaluate the effects ...
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The calculation of carrying capacity and allowable use of key species is necessary for sustainable range management. Vegetation degradation and soil and water loss can be prevented in the rangeland through calculating the actual carrying capacity. The aim of this research was to evaluate the effects of different harvesting intensities on forage production of Puccinellia distans in saline lands of West Azarbaijan Province. Initially, an area of 0.5 hectare was selected in saline rangelands, located around the Urmia Lake and in the first year of the study excluded from grazing. Forty individuals of the studied species were selected and harvested monthly by clipper at harvesting intensities of 25%, 50%, and 75%. Ultimately, the effects of harvesting intensities on phenological characteristics, forage production, vigor and vitality and mortality of each species were investigated. According to the obtained results, increased harvesting intensity resulted in decreased vitality of the studied species. Our results clearly showed that a harvesting intensity of 50% could be recommended with the least negative effects on plant characteristics and optimal use of forage.