Mohammad Gheitury; Borzou Yousefi; Reza Siahmansour; Mosayeb Heshmati
Volume 30, Issue 1 , April 2023, , Pages 111-130
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.
Reza Siahmansour; Mohammad Fayaz; Saeedeh Nateghi; Rostam Khalifehzadeh; Ali Mohammadian
Volume 26, Issue 4 , December 2019, , Pages 887-903
Abstract
Knowledge of preference value of plant species is one of the essential requirements for determining forage available and consequently, calculation of grazing capacity for rangeland habitats. This project was investigated in 36 species including of 21 perennials and 15 annuals species. For this purpose, ...
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Knowledge of preference value of plant species is one of the essential requirements for determining forage available and consequently, calculation of grazing capacity for rangeland habitats. This project was investigated in 36 species including of 21 perennials and 15 annuals species. For this purpose, during four-years period (2007-2010) in each month of the growing season (spring and summer) film was taken from a non-pregnant and non -lactating unit adult ewes (Lori)for at least 1800 seconds with an average weight of 50 kg inside the flock which were grazing in rangeland. Results indicated that annual grasses such as Boissiera squarrosa, Bromus danthonia, Bromus tectorum, Heteranthelium piliferum had the highest grazing time with a total duration of 3083 seconds compared to other species. Subsequent species including of Agropyron trichophorum with 2594 seconds, Bromus tomentellus with 1232 seconds, Onobrychis melanotricha with 681 seconds, broadleaf herbaceous annual such as Helianthemum ledifolhum, Viciea peregerina, Diplotaxis erucoides, talaspi perfoliatum, Minuartia obtusiloba with 670 second and Hordeum bulbosum with 565 second were ranked in the next. Finally, it was found that annual grasses and shrubs in May, perennial grasses in June, and broadleaf herbaceous annual in July have quite palatable and located in Class I. Also, total grasses and perennial forbs in July, annual forbs and shrubs in May and June have fairly palatable respectively which have located in class (II) and vegetative forms have palatable class III in other months.
Reza Siahmansour; Mohammad fayaz
Volume 25, Issue 4 , February 2019, , Pages 853-862
Abstract
Unfortunately, due to the improper use of natural resources, tremendous changes on the Earth happened which are harmful to human beings. The multidimensional nature of sustainable development has caused to pay more attention to the use of compatible, resistant, productive, high quality and palatable ...
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Unfortunately, due to the improper use of natural resources, tremendous changes on the Earth happened which are harmful to human beings. The multidimensional nature of sustainable development has caused to pay more attention to the use of compatible, resistant, productive, high quality and palatable species. One of these species is Astragalus curvirostris as a permanent species, which one of its habitats is in Beluman rangelands with an average height of 1960 meters above sea level and an average annual rainfall of 593.3 mm. In two times and two methods of planting, split plots were arranged in a randomized complete block design with three replications during four years (from 2013 to 2016). The main plot included two treatments of planting season consisted of autumn and spring, and the subplots included two methods of seed cultivation and seeding. Analysis of variance was used to compare significant differences between treatments, and distribution of mean treatments was analyzed by Duncan test. The results showed that there was a significant difference between the average number of available plant stands in different treatments including autumn seed sowing, autumn seed spreading, spring seed sowing and spring seed spreading at 1% level (P≤0.01). It means that its cultivation type and season have different performance on plant coverage. In addition, there was a significant difference between the plots at 1% level, which in fact can depend on the implementation of the treatments in each plot. Finally, it was found that Astragalus curvirostris achieved the best level of success in autumn and the seed sowing method.
reza siahmansour; Morteza akbarzadeh; Ehsan Zandi Esfahan
Volume 24, Issue 2 , July 2017, , Pages 418-428
Abstract
This research was carried out at the Zagheh research station in Lorestan province. A number of 440 individuals in each year and 2200 individuals in five years were cut and weighted inside and outside the exclosure. The difference in weight between the individuals outside and inside the exclosure indicates ...
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This research was carried out at the Zagheh research station in Lorestan province. A number of 440 individuals in each year and 2200 individuals in five years were cut and weighted inside and outside the exclosure. The difference in weight between the individuals outside and inside the exclosure indicates the amount of consumption. According to the results, there is a significant difference between the mean value of forage production and consumption in months and in different species (P<0.01). For the average of four years, the highest and lowest forage production was recorded in the third and second year, respectively. On average, forage production was calculated to be about 1,177 kg per year. On average during four years, 80% of the production was used by livestock. In all years, the highest amount of forage was produced in May. Ono.melanotricha, As. Remotijogus and As.bungei are consumed up to the basal area, while the highest consumption rate for Cen.virgata was obtained in June. Perennial grasses of the study site like Hor. bulbosum, Br.tomentellus, Festuca ovina, Stipa wiesnerii are also under severe grazing pressure. Under heavy grazing over a season, some species like Picris strigosa are not able to rejuvenate and their roots are shattered with little stress. Therefore, the imbalance between production and exploitation and inappropriate distribution is a major factor in the degradation of vegetation and rangeland ecosystems.