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.
Asad Sadeghpour; Javad Motamedi; Esmaeil Sheidai Karkaj; Mostafa ghanamijaber
Volume 25, Issue 4 , February 2019, , Pages 944-955
Abstract
Knowing medicinal plants, measuring structural features and their species diversity indices are of the essential requirements to determine the suitability of rangelands for the use of medicinal plants. In this regard, the research was carried out in the mountain rangelands of Anbaran. For this purpose, ...
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Knowing medicinal plants, measuring structural features and their species diversity indices are of the essential requirements to determine the suitability of rangelands for the use of medicinal plants. In this regard, the research was carried out in the mountain rangelands of Anbaran. For this purpose, vegetation cover was measured using 320 plots of one square meter, with a distance of 10 meters from each other along 100-meter transects in 16 vegetation types, and the values of species diversity indices in different elevation classes and aspects were calculated. Based on the results, 16 medicinal species are distributed in the plant composition, with a relative importance varying from 0.9 to 59. The highest relative importance is related to Verbascum erianthum, Cynodon dactylon and Acroptilon repens, and the least belongs to Papaver acrochaetum, Hyoscyamus arachnoideus, Iris falcifolia, Allium scabriscapum and Matricaria chamomilla.The results showed that the values of the Shannon–Winear in the altitudes of 1750-1500 meters and 1750-200 meters were 0.569 and 0.651, respectively, showing no significant difference with each other. The value of the index in the northern and southern directions is equal to 0.691 and 0.511, and the northern aspects are more favorable than the southern ones. Therefore, with regard to the range of Shannon–Winear index (0-4.5), it seems that the rangelands are not desirable for the species diversity of medicinal plants, which is necessary to increase species diversity with direct management. The findings of this study can be used to locate medicinal plants in order to protect, exploit, seed production and provide part of the livestock holder’s income.