Azam Khosravi Mashizi; Mohsen Sharafatmandrad
Volume 28, Issue 2 , June 2021, , Pages 266-279
Abstract
The complexities of the relationship between biodiversity and human welfare can be simplified by identifying the impact of species diversity on ecosystem function. Since annual production plays an important role in the grazing management and sustainability of rangeland ecosystems, this study examines ...
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The complexities of the relationship between biodiversity and human welfare can be simplified by identifying the impact of species diversity on ecosystem function. Since annual production plays an important role in the grazing management and sustainability of rangeland ecosystems, this study examines the relationship between species diversity and annual production of semi-arid rangelands in Khabar National Park under the hypothesis of ecological nest. The annual production of species in 1×1 square plots was estimated in two rangeland types of Artemisia sieberi and Artemisia sieberi- Stipa barbata using the cutting and weighing method. The results showed that although the two plant types differed significantly in terms of annual production (p < /em> <0.05), but there was no significant difference between the two rangeland types in terms of diversity indicators of Shannon, Simpson, Margalf, Manichae, and uniformity index. Pearson’s correlation analysis showed that annual production had a positive and significant relationship with species diversity indicators in Artemisia sieberi- Stipa barbata type; however, no significant relationship was observed in Artemisia sieberi. Contrary to the hypothesis of the ecological nest, species did not have the same contribution in annual production, and the dominant species of Artemisia aucheri had the highest contribution in production. According to the hypothesis of mass ratio, the diversity of functional traits in the dominant species has led to better success of rangeland type the Artemisia aucheri- Stipa barbata than the Artemisia aucheri in terms of annual production. In general, it is recommended that conserving of the composition of plant communities is more important to protect ecosystem services compared to maintaining the maximum number of species.
Hamzeh Ali Shirmardi; Atosa Mojiri; Mostafa Saeedfar; Mohamadreza Tatian; Parviz Gholami
Volume 23, Issue 1 , June 2016, , Pages 138-149
Abstract
Livestock grazing can lead to changes in plant composition. In this study, the effect of four grazing intensities including heavy, moderate, light and no grazing (exclosure) were studied on vegetation indices in order to improve management practices and proper planning for sustainable use of rangelands ...
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Livestock grazing can lead to changes in plant composition. In this study, the effect of four grazing intensities including heavy, moderate, light and no grazing (exclosure) were studied on vegetation indices in order to improve management practices and proper planning for sustainable use of rangelands in Karsanak and Bardeh area in Chaharmahal & Bakhtiari province of Iran. Therefore, vegetation sampling was done to record canopy cover percentage and vegetation composition under four grazing intensities. Data were analyzed by one-way ANOVA, t-test,andordination method (CCA) to assess vegetation changes under different grazing intensities. Results showed that plant species such as Agropyron repens, Bromus tomentellus, Astragalus effuses and Poa bulbosa were more found in exclosure and light grazing area.The major species found in heavy grazing area were Boissiera squarrosa, Echinops leiopolyceras, Sisymbrium irio and Euphorbia heteradenia. Due to the vegetation damage and reduction of palatable species, a moderate grazing is recommended in the study rangeland.
Nematollah Madadi Zadeh; Hossein Arzani; Ghavaloddin ahedi; Najmeh Faryabi
Volume 21, Issue 1 , June 2014, , Pages 128-138
Abstract
In the current study, the effects of exclosure were examined on rangeland vegetation at two study sites including, reference site (inside the exlosure) and critical site (outside the exclosure). Research was conducted by the systematic-random method and 160 2*1.5 m plots were established. Inside each ...
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In the current study, the effects of exclosure were examined on rangeland vegetation at two study sites including, reference site (inside the exlosure) and critical site (outside the exclosure). Research was conducted by the systematic-random method and 160 2*1.5 m plots were established. Inside each plot, the percentage of canopy cover, litter, gravel and bare soil as well as density of class I, II, and III species were recorded. Dry matter yield was also calculated. Four-factor method and trend balance method were applied to determine the range condition and range trend, respectively. According to the obtained results, due to the exclosure, litter, yield, canopy cover percentage and class I species composition increased up to 24.72%, 37.42%, 23.6%, and 80.6%, respectively. On the other hand, the percentage of bare soil, gravel, and class III species composition decreased to 34.29%, 17.16%, and 26.96%, respectively. Mean differences in all parameters inside and outside the exclosure were significant at both study sites. Our results also indicated that exclosure led to the improvement of range condition and range trend.