Javad Motamedi; Esmaeil Sheidai Karkaj; Azizeh Babazadeh; Morteza Mofidi Chelan
Volume 29, Issue 2 , July 2022, , Pages 166-175
Abstract
One of the objectives in rangeland management is the accurate and rapid determination of forage production to determine grazing capacity. The relationship between forage production and morphological characteristics was investigated in this study. For this purpose, two grazed and non-grazed units were ...
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One of the objectives in rangeland management is the accurate and rapid determination of forage production to determine grazing capacity. The relationship between forage production and morphological characteristics was investigated in this study. For this purpose, two grazed and non-grazed units were selected in the mountainous rangelands of Nazlouchay, Urmia. In each of them, the morphological characteristics of A. aucheri, as the only dominant plant species that accounts for more than 50% of the plant composition, were measured within 60 one-square-meter plots located along with 100-meter transects in July 2017. After cutting off bases growth, the dry weight of the samples was determined, and its regression relationship with morphological characteristics was examined using hierarchical regression. The results showed that it was possible to estimate A.aucheri production in the unit where the plant bases were not grazed using multiple linear regression models based on diameter, average crown size (D1), collar diameter (D2), and height (H). In the grazed units, where plant bases were grazed in the fall of last year, only the average diameter of the crown (D1) and height (H) was validated with multiple linear regression models, as the best model with RMSE equal to 3.53 and coefficient of 0.52. Due to the relatively good performance of the model and the preference for combining several morphological features in production estimation, separating models into inside and outside the exclosure can play a role in rangeland monitoring and production estimation to calculate grazing capacity and assess the intensity of rangeland utilization.
Reza Chamanpira; Reza Siahmansour; Hossein Arzani
Volume 27, Issue 2 , June 2020, , Pages 204-214
Abstract
One of the main goals of rangeland assessment is to obtain the amount of forage production of rangeland species because it plays an essential role in determining rangeland capacity and grazing management. Measuring the amount of production requires a lot of time and costs, so finding cheap, fast and ...
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One of the main goals of rangeland assessment is to obtain the amount of forage production of rangeland species because it plays an essential role in determining rangeland capacity and grazing management. Measuring the amount of production requires a lot of time and costs, so finding cheap, fast and scientific methods to estimate the amount of production can be a great help in assessing vegetation and rangeland management. The purpose of this study was to find a suitable relationship between the percentage of canopy cover of species and plant classes with their production amount. For this purpose, the percentage of canopy cover of the species was examined during a six-year statistical period within 60 plots (1m2) located along six transects (200 m). In addition, each year, the amount of species production in a quarter of the plots (25% of them) that were caged to prevent possible grazing, was measured by clipping. To determine the amount of total forage production, the regression relationship between canopy cover and species production was used and based on the significance of the equation (p≤ 0.05) and coefficient of determination (R²), the best equation was fitted. The results showed that there was a significant correlation (p≤ 0.01) between production as a dependent variable and the percentage of canopy cover of the species as an independent variable. The coefficient of determination for each of the classes I, II and III were 0.77, 0.87 and 0.92, respectively, which provide the most appropriate linear production-canopy relationship for rangeland management.
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.
Yaser Ghasemi Aryan; Hossein Arzani; Esmaiel Filekesh; Reza Yari
Volume 20, Issue 1 , June 2013, , Pages 1-10
Abstract
Determination of grazing capacity is considered as one of the most fundamental aspects of range management and understanding the effective factors on it is of utmost importance. Since the amount of forage production in a growth period is the basis for calculation of grazing capacity, in this research ...
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Determination of grazing capacity is considered as one of the most fundamental aspects of range management and understanding the effective factors on it is of utmost importance. Since the amount of forage production in a growth period is the basis for calculation of grazing capacity, in this research the estimation of production through the measurement of plant’s dimensions was investigated. For this purpose, the habitat of Artemisia siberi was determined and then 8 transects of 50 m length were established with 10 m intervals by random-systematic method. The height and diameter of 40 species of Artemisia siberi with different dimensions were recorded and the production of each species was clipped and weighted after drying. All data were analyzed by SPSS. Results showed that there was a significant linear correlation between production as a dependent variable and volume, canopy cover and height of Artemisia siberi as independent variables (R2= 0.88, 0.84, and 0.74, respectively) at 1% probability level. Finally, the relationship between production and volume was identified as the best linear relationship.
Jahan bakhsh Pairanj; Ata... Ebrahimi; Abalfazl Ranjbar; Mohammad Hasan zadeh
Volume 18, Issue 4 , September 2012, , Pages 593-607
Abstract
Evaluation of forage production is an important issue in determining grazing capacity of rangelands. There is no doubt that all forage production in rangelands is not evenly accessible and different factors affect the accessibility of forage. In this research, factors affecting forage availability were ...
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Evaluation of forage production is an important issue in determining grazing capacity of rangelands. There is no doubt that all forage production in rangelands is not evenly accessible and different factors affect the accessibility of forage. In this research, factors affecting forage availability were studied. After a wide literature review, factors of distance from water supplies, density of shrubs, slope and land uses were identified as the main factors preventing forage accessibility. Forage production and shrub density were respectively measured using clip and weighing method in quadrates and distance method. Forage production measurements in representative area were extrapolated to the whole area using IRS satellite images. In this research, 18 vegetation indices were examined as forage production data (independent factor) were regressed against vegetation indices values (dependent factor) using SPSS. Map of forage production was created based on the best fit regression. Then, with adjusting all limiting factors, the map of accessible forage production was created based on the tables. The maps were illustrated and available forage was calculated after implementing adjustment of each factor. Statistical results showed significant differences (p≤0.05) between forage production with considering slope and shrub density and forage production based on all limiting factors of forage accessibility. While distance from water supplies and other land uses had no significant effect on forage production
Aman Rahbar; Ali Mir jalili; Naser Baghestani Meybodi
Volume 14, Issue 4 , February 2008, , Pages 579-588
Abstract
Knowing forage quality is necessary for assigning grazing capacity in range management program. For this aim, forage quality of two dominant range plants, Artemisia aucheri, and Peteropyron aucheri were studied in water spreading area of Heart station in Yazd province. Plant samples taken for two subsequent ...
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Knowing forage quality is necessary for assigning grazing capacity in range management program. For this aim, forage quality of two dominant range plants, Artemisia aucheri, and Peteropyron aucheri were studied in water spreading area of Heart station in Yazd province. Plant samples taken for two subsequent years from water spreading and control plots. Plant samples analyzed in laboratory and elements such as P, Ca, Mg, K, Na, Fiber, Fat and Proteins were measured. Statistical analysis indicated that in two years of study period, some elements has increased in water spreading plots (p<0.05), but, acceptable changes in forage quality of the two specie can not be reported.