Abdolhamid Hajebi; Mohammad Amin Soltanipoor; Mohammad Fayaz; Ehsan Zandiesfahan
Volume 29, Issue 4 , January 2023, , Pages 485-497
Abstract
One of the important factors in determining the grazing capacity of rangelands is determining the preferred value of rangeland plants according to the type of livestock using the rangeland and its changes during the grazing season. In this study, the preference value of rangeland species in Zaminsang ...
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One of the important factors in determining the grazing capacity of rangelands is determining the preferred value of rangeland plants according to the type of livestock using the rangeland and its changes during the grazing season. In this study, the preference value of rangeland species in Zaminsang rangeland in Hormozgan province in the months of grazing season (January to May) and different years (2007-2010) was investigated. To determine the preference value, the method of utilization percentage of plant species and determination of preference index were used. The results were analyzed in a split plot statistical design in time in a randomized complete block design in SAS software and the statistical mean of the studied trait was compared with LSD test. The results showed that the most preferred livestock is primarily Aeluropus lagopoides and Atriplex leucoclada and Alhagi graecorum. The lowest percentage of exploitation was from Halocnemum strobilaceum and Desmostachya bipinnata. Based on the preference value index classification, Aeluropus lagopoides and Atriplex leucoclada species are relatively palatable species (relative preference), Alhagi graecorum and Halocnemum strobilaceum species are moderately palatable species (moderate preference) and Desmostachya bipinnata was one of the almost non-palatable (relative avoidance) species.
Ali Asghar Naghipour Borj; Sina Nabizadeh; Javad Pourezaie
Volume 26, Issue 3 , September 2019, , Pages 587-598
Abstract
Fire is one of the most important influencing factors on the structure and composition of plant communities, especially in arid and semiarid rangelands. This study was designed to investigate the role of fire on vegetation dynamics in semi-steppe rangelands of Central Zagros. ...
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Fire is one of the most important influencing factors on the structure and composition of plant communities, especially in arid and semiarid rangelands. This study was designed to investigate the role of fire on vegetation dynamics in semi-steppe rangelands of Central Zagros. A stratified random sampling was used to collect the data from six sites with one and five years after the last fire. At each rangeland site, 20 plots with four square area meters, 10 plots in the burned sites and 10 plots in the control sites, were used. The cover percentage of each species was accurately recorded. A one-way analysis of variance and Tukey's test were used to compare each of the variables. The results showed that the fire significantly reduced the vegetation cover and litter, and increased the bare soil surface in the region. The composition of the fire region was close to the control area after a period of five years. The fire caused a decrease in the percentage of shrubs and an increase in the proportion of perennial grasses, annual grasses, and annual forbs in the region. The fire also changed the vegetation composition of rangelands, so that the proportion of hemicryptophytes, therophytes, and geophytes were decreased while chamaephytes increased. Fire also increased the proportion of high and moderate palatable species (class I and II) and reduced the proportion of class III species. Based on the results of this study, it can be concluded that the fire reduces litter and increases the bare soil; consequently, the soil erosion is exacerbated, hence this should be considered in rangeland management. Overall, uncontrolled fires in the semi-arid regions of the country will not lead to the restoration of vegetation cover.
Aazam Khosravi Mashizi; Gholamali Heshmati; Aadel Sepehri; Hossein Azarnivand
Volume 17, Issue 4 , November 2011, , Pages 549-563
Abstract
Considering previous studies which showed no significant relation between the distance from water point and total vegetation cover, in current research plant species were classified based on life forms (shrub, bush, perennial grass, perennial forbs and annual forbs) and palatability classes (I, ...
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Considering previous studies which showed no significant relation between the distance from water point and total vegetation cover, in current research plant species were classified based on life forms (shrub, bush, perennial grass, perennial forbs and annual forbs) and palatability classes (I, P and PI). One way ANOVA was applied to determine the variations with distance from water point 8 main directions. Results showed that 8 main directions had no significant effect on vegetation cover and palatability classes of studied life forms. While life forms and palatability classes had different reactions to grazing according to the distance from water point. As shrubs, bushes, perennial grasses and palatability class I increased and annual forbs and palatability class PI decreased with distance from water point. Perennial forbs and palatability class P had uniform distribution. Using results of Duncan multiple range test a critical area was determined at 400 m distance from water point. In the mentioned critical area, shrubs and bushes showed a decrease in vegetation composition while annual forbs increased. Palatability class I also was eliminated in this area. According to the variations in perennial grasses and palatability classI, very sensitive to grazing, it can be concluded that grazing intensity had been very severe at a distance of 800-1000 m from water point.