Abbasali Sanadgol
Volume 10, Issue 3 , September 2019, , Pages 321-338
Abbasali Sanadgol; Mohammadreza Moghaddam
Volume 10, Issue 1 , August 2019, , Pages 77-94
Seyed Mehrdad Kazemi; Hamidreza karimzadeh; Hosein Bashari; Mostafa Tarkesh Esfahani
Volume 25, Issue 4 , February 2019, , Pages 789-804
Abstract
Considering the role and importance of grazing on vegetation structural changes, thisstudy aimed to assess the effects of various grazing intensities on vegetation parameters in semi-steppe rangelands of Alavigeh, Isfahan. Three rangeland locations with relatively homogeneous ecological conditions ...
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Considering the role and importance of grazing on vegetation structural changes, thisstudy aimed to assess the effects of various grazing intensities on vegetation parameters in semi-steppe rangelands of Alavigeh, Isfahan. Three rangeland locations with relatively homogeneous ecological conditions and various long-term grazing intensities (light, moderate and heavy) were selected. Four perpendicular transects with 100 meters length (two parallel transects and tow transects perpendicular to the general slope of the area) were established in each site and vegetation parameters including vegetation cover, density and palatability class of the species were recorded in 10 plots. The Margalef richness index and Shannon-Vainer diversity and evenness indices of the plots were calculated. A one way ANOVA was used to compare the vegetation parameters in sites with various long term grazing intensities. According to the results, the sites with low and moderate grazing intensities had higher plant density and vegetation cover compared with site grazed heavily and these vegetation indices varied significantly between the sites (P< 0.05). The species composition of the light and moderate grazing areas mainly included class II species with 72% and 54%, respectively. The heavily grazed site was dominated by the species with low grazing palatability (69%). The plant diversity, richness and evenness indices of the sites with low and moderate grazing intensities varied significantly (p < 0.05). The log normal was the best fitted parametric model among species abundance models for the low and moderate grazed sites, indicating a stable vegetation community. Log series were fitted to diversity data in the heavy grazed site, indicating an unstable vegetation community. RDA analysis revealed that there was a distinct grazing gradient and three vegetation zones could be clearly separated with various vegetation compositions. Although vegetation condition is appropriate in the sites with low grazing intensity, also the vegetation regeneration can benefit from moderate grazing intensity. Biological considerations are required in the management of rangeland ecosystems in arid and semi-arid ecosystems due to the fragile nature of these ecosystems.
Fatemeh Alilou; farshad keivan Behjou; esmaeil sheidae karkaj; reza ahmadkhani; javad motamedi
Volume 24, Issue 3 , October 2017, , Pages 596-609
Amirhosein Kavianpour; zeynab Jafarian; Abazar Esmaeli Ouri; Ataollah Kavian
Volume 23, Issue 3 , January 2017, , Pages 593-605
Abstract
Soil is a suitable bed for plant growth and development of vegetation, so that if it is not conserved, it will result in the nutrient deficiency, soil erosion and degradation of natural resources. In this research, the spatial variability of some chemical and physical properties of soil was investigated ...
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Soil is a suitable bed for plant growth and development of vegetation, so that if it is not conserved, it will result in the nutrient deficiency, soil erosion and degradation of natural resources. In this research, the spatial variability of some chemical and physical properties of soil was investigated in different vegetation covers (minimum, moderate and maximum) and different grazing intensities including reference area (light grazing), key area (moderate grazing) and critical area (heavy grazing) in the winter rangelands of Nasho, Mazandaran province. Soil samples were collected from 0-30 cm depth according to a systematic grid (30×30 m) and then transferred to the laboratory. Soil chemical and physical properties including acidity (pH), Electrical Conductivity (EC), caco3, bulk density, particle density, total phosphorus, total nitrogen, available potassium, organic matter, initial moisture content, percentage of clay, silt and sand, sodium, calcium, and magnesium were measured in laboratory. In addition, soil surface resistance was measured in the field with a portable penetrometer. The results of statistical analysis showed that different grazing intensities had significant effects on organic matter, available potassium, pH, EC, caco3, calcium, bulk density, initial moisture content, and surface resistance of soil. Different vegetation covers had significant effects on silt percentage, organic matter, pH, EC, calcium and initial moisture content of soil.
Behnam Bahrami; Reza Erfanzadeh; Javad Moetamedi
Volume 22, Issue 1 , June 2015, , Pages 47-58
Abstract
Study on the effect of different grazing intensities on some soil characteristics could be helpful in management and conservation of soil and vegetation. In this study, six key areas were selected with different in grazing intensities. The grazing intensities level for Makueian sheep race was recognized ...
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Study on the effect of different grazing intensities on some soil characteristics could be helpful in management and conservation of soil and vegetation. In this study, six key areas were selected with different in grazing intensities. The grazing intensities level for Makueian sheep race was recognized based on the distance to the villageand the cover percentage of invasive, increaser and decreaser species. In each area, soil sampling was done along systematically established transects, in which 18 soil samples were collected from two depths (0-15 and 15-30 cm). Soil samples were then transferred to the laboratory for the chemical and physical analysis of 17 soil characteristics.The results of principle component analysis showed that silt percentage, coarse and fine aggregate percentage, saturation percentage, and particulate organic carbon of upper layer (0-15 cm) as well as soil texture, the carbon of coarse and fine aggregates, EC, and the bulk density of lower layer (15-30 cm) were more sensitive to sheep grazing as compared to other soil characteristics.
Elham Fakhimi Abarghouie; Seyed Akbar Javadi
Volume 21, Issue 1 , June 2014, , Pages 109-118
Abstract
From the perspective of rangeland ecology, awareness of the effects of livestock grazing on the changes of structure, plant vegetation and soil characteristics is essential. The aim of this study was to determine the effect of different grazing intensities including heavy (0-200 m distance from water ...
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From the perspective of rangeland ecology, awareness of the effects of livestock grazing on the changes of structure, plant vegetation and soil characteristics is essential. The aim of this study was to determine the effect of different grazing intensities including heavy (0-200 m distance from water point), moderate grazing (200- 800 m) and light grazing (800-1200 m) intensities on vegetation indices and soil characteristics in Nodushan region, Yazd province of Iran. For this purpose, plant vegetation cover and composition were recorded under three grazing intensities. Soil was sampled from depths of 0-30 cm. Data were analyzed by one way ANOVA, t-testandordination method (CCA) to assess the vegetation response in different grazing intensities. Results showed that plant species such as Astragalus achrochlarus, Salsola arbusculata and Tragopogon sp.were found in light grazing area.Allysum minus, Artemisia sieberi, Poa sinacia, Iris songarica, Lactuca glacifolia and Stipa barbata were identified in moderate grazing area. Eryngium sp., Cousinia desertii, Bromus tectorum and Peganum harmala were the major species in heavy grazing area.Soil properties including N, P, K, OC, EC and pH were measured. According to the results, nitrogen and soil organic matter were decreased by increasing grazing intensities but P, K, EC and pH were increased. Since grazing pressure causes damage to vegetation and some soil properties, a moderate grazing is recommended for sustainable utilization of rangelands.