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.
Ali mohebbi; Farhang Ghasriani; Mina Bayat; Gholamhosein Rahmani; qasem khodahami; ghasemali abarsaji; Mohamad ali Dehghani Tafti; Farideh Saghafi Khadem
Volume 24, Issue 3 , October 2017, , Pages 471-477
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.
Sedigheh Zare kia; Farhang Ghasriani; Mina Bayat; Hajar Nemati
Volume 22, Issue 2 , August 2015, , Pages 266-274
Abstract
Allowable use is one of the most important factors in determining grazing capacity. The present study was carried out to determine the allowable use of Salsola laricina in Khoshkerood site of Saveh. In this research, four treatments including 25%, 50% ,75% harvesting and no harvesting (control) ...
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Allowable use is one of the most important factors in determining grazing capacity. The present study was carried out to determine the allowable use of Salsola laricina in Khoshkerood site of Saveh. In this research, four treatments including 25%, 50% ,75% harvesting and no harvesting (control) were compared during three years. The results showed that the effect of the year and interaction of different harvesting intensities and year were statistically significant at the level of one percent. In the first year of study, there was no significant difference among treatments; however, in the subsequent years, the effects of treatments were visible. So that the treatments had the most impact on the speciesin the last year. It was clear that there was not significant difference between the 25% harvesting intensity and control treatment. These treatments had the most forage production and also, there was not a significant difference between the other two treatments. The observations showed that the vitality of species in control treatment was less than that of 25% and 50% harvesting intensities, indicating that grazing can increase the plants vitality. Based on the AMMI analysis, the first interaction principal component (IPC1) was significant at the level of 1%, so that 98.2% of the sum of squares of the interaction could be expressed by IPC1. According to the biplot of the IPC1 and mean production, the lowest production rate and stability was recorded for the harvesting intensity of 75%. According to the results, it can be stated thataharvesting intensity of 25% guarantees the survival of S.laricinain this region with no negative effect on the vitality of Salsola laricina.
Gholamreza Goudarzi; Ali Farmahini Farahani; Hamidreza Mirdavoudi
Volume 19, Issue 3 , December 2012, , Pages 395-405
Abstract
Determination of allowable use of the key species of rangelands is necessary to calculate the rangeland capacity. Actual rangeland capacity could be determined through having the exact values of this factor for rangeland species and the destruction of vegetation, soil and water loss on rangelands can ...
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Determination of allowable use of the key species of rangelands is necessary to calculate the rangeland capacity. Actual rangeland capacity could be determined through having the exact values of this factor for rangeland species and the destruction of vegetation, soil and water loss on rangelands can be avoided. In this research, Artemisia aucheri, Bromus tomentellus, Kochia prostrata, Asperula glomerata and Buffonia koelzii were investigated as the key species of Arak Enjedan rangelands. A key area of one hectare was selected in Arak Enjedan rangelands and was fenced in the first year of the study. Then, 40 individuals were selected from each species and harvesting intensities of 25, 50, 75% and control treatment were implemented. Harvesting was done by a clipper monthly during grazing season for 4 years. The influence of harvesting was investigated in the second to fifth years through the study of changes in phenological characteristics, forage and seed production, vitality, and mortality and other characteristics of plant species. Results showed that increasing the harvesting intensity caused problems and decline of vital abilities of all species especially, As. glomerata and Br. tomentellus that are more palatable species. According to the results, an allowable use of 25% is recommended for Br. tomentellus and As. Glomerata while for Ar. aucheri, Ko. prostrata and Bu. Koelzii an allowable use of 50% was obtained with the least negative effects on plant characteristics. Results of the analysis of variance for forage production data were significant for all of the studied species in %1 level of probability.