Hasan Eslami; Javad Motamedi (Torkan); Habib Nazarnejad; Esmael Sheidaye Karkaj
Volume 26, Issue 3 , September 2019, , Pages 613-628
Abstract
Species diversity is one of the characteristics indicating changes in rangelands. In this regard, the relationship between range condition as a result of managerial measures and species diversity was investigated. Spearman correlation test and one-way analysis of variance were used for ...
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Species diversity is one of the characteristics indicating changes in rangelands. In this regard, the relationship between range condition as a result of managerial measures and species diversity was investigated. Spearman correlation test and one-way analysis of variance were used for testing the variations of Shannon-Wiener diversity index values of plant types with their conditions. Then, by plotting rank-frequency curves and applying the frequency distribution models, the vegetation types with higher diversity were identified and their relationship with range condition was interpreted. The results showed that Shannon-Wiener diversity index had no significant correlation with range condition. Range condition had no significant effect on the amount of diversity and all three categories of condition (good, average, poor) were classified according to the mentioned index. In general, no significant trend was observed between range condition and amount of diversity. The results suggest that the high values of numerical indices of diversity are not the reason for the improvement of range condition, but their species composition and abundance should also be investigated. Drawing rank-frequency curves and matching the frequency distribution models showed that plant types with good and moderate condition, species with less abundance, were less frequently observed and its curve had a mild slope than those with poor condition, so their diversity was higher. In most plant types, the geometric series model was consistent, indicating low plant diversity and poor range condition. In general, concerning the degree of conformity of the results of the frequency distribution models with the condition of the plant types, the results emphasize the need to pay attention to the parametric indices of species diversity in rangeland health assessment.
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.
Alireza Eftekhari; Hosein Arzani; Ehsan Zandi Esfahan; esmaiel Alizadeh
Volume 23, Issue 2 , September 2016, , Pages 218-209
Abstract
Given the breadth and importance of rangelands in water and soil conservation, fodder production and environmental services and evidence of the destruction of this resource, some measures must be taken to prevent damage and also improve its condition. One of the most important measures is preparation ...
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Given the breadth and importance of rangelands in water and soil conservation, fodder production and environmental services and evidence of the destruction of this resource, some measures must be taken to prevent damage and also improve its condition. One of the most important measures is preparation and implementation of Range Management Plans. Hence, it is necessary to consider implemented projects to know that how much they have contributed in preventing damage and improving rangelands. In this research winter rangelands (with and without Range Management Plans) were investigated in Zarandieh. For this purpose, 16 rangelands with Range Management plan and 14 rangelands without Range Management plan were selected so that all management types (private, collective and different areas of rangeland) were taken into consideration with same climate conditions as far as possible. Consequently all rangelands were selected from Mamoonieh-Zarandieh region with warm and dry weather. After calculating the number of plots (60) and its size (2m2) in each vegetation type, a reference area was selected in which vegetation factors including canopy cover, yield, density, litter, species richness, range condition and trend were evaluated in time of range readiness. Statistical analysis of data was performed by t-test. According to the results, there were significant differences between studied rangelands in most of factors. Overall result of the study showed a better condition for rangelands with Range Management Plans.