Farhad Aghajanlou; Peyman Akbarzadeh; Alireza Eftekhari
Volume 31, Issue 4 , January 2025, , Pages 323-346
Abstract
Background and Objectives
Growing awareness of environmental issues and sustainable natural resource management require continuous study and monitoring across various timescales and locations. Ecosystems, including rangelands, undergo constant change. Given their ecological significance, economic ...
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Background and Objectives
Growing awareness of environmental issues and sustainable natural resource management require continuous study and monitoring across various timescales and locations. Ecosystems, including rangelands, undergo constant change. Given their ecological significance, economic role, and vulnerability to irreversible alterations, rangeland monitoring is essential for their ongoing assessment.
Research Methodology
This study monitored changes in vegetation cover and soil indicators over five years at the Dagestan site in Zanjan Province. Field evaluations included plant and soil factors. Plant-related data encompassed canopy cover percentage, litter percentage, species density (where applicable), production, rangeland condition, and trend. Assessments were conducted using established methods, with adequate sampling and proper distribution across different plant communities during both initial evaluation and subsequent monitoring. Soil factors included pH, electrical conductivity, nitrogen, phosphorus, potassium, organic matter content, bulk density, and soil texture.
Results
Statistical analysis of vegetation changes and their effects on soil indicators under grazing and flooding over the five years revealed significant differences in most parameters. Total canopy cover and rangeland production differed significantly between years and site types (grazed vs. exclosure) at the 1% and 5% probability levels, respectively. The highest vegetation cover (56%) was observed in the grazed area in 2018, while the lowest (30%) occurred in the exclosure in 2021. Peak total production (126 g m<sup>-2</sup>) was recorded in the exclosure in 2018, while the lowest (48.7 g m<sup>-2</sup>) occurred in the exclosure in 2021. Total species density showed no significant differences between years, site types, or their interaction. However, on average, shrub density was higher outside the exclosure, while grass density was higher inside, indicating a significant difference. Vegetation changes due to grazing and flooding affected certain soil parameters. Increased grazing intensity correlated with decreased potassium, phosphorus, nitrogen, organic carbon, and electrical conductivity in the topsoil.
Conclusion
Over the five-year study period, grazing significantly influenced vegetation, and the decline in vegetation cover had a notable impact on soil physical and chemical properties. Vegetation changes in the study area were gradual and shaped by rangeland management practices. Regular monitoring of qualitative and quantitative changes in rangeland vegetation is essential for informed planning and the implementation of effective management strategies for sustainable rangeland use.
Bakhtiar Fatahi; Soheila Aghabeigiamin; Alireza Ildoromi; Maedeh ghorbanpour Dalivand
Volume 26, Issue 2 , July 2019, , Pages 302-312
Abstract
Land use change, land abandonment, overgrazing, expansion and spread of exotic species are of the most important challenges in the rangelands of the country. For this reason, in this research, it has been attempted to address the challenges by presenting a single improvement solution. Therefore, the ...
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Land use change, land abandonment, overgrazing, expansion and spread of exotic species are of the most important challenges in the rangelands of the country. For this reason, in this research, it has been attempted to address the challenges by presenting a single improvement solution. Therefore, the perennial rainfedd alfalfa was used for cultivation in degraded rangelands or abandoned lands for both goals of rangeland reclamation and carbon sequestration. Three rangelands were studied in the protected area of Lashgardar-Malayer reclaimed rangeland via alfalfa, medium grazing, and degraded rangelands. In each of these rangelands, sites were selected for sampling. The size and number of plots were determined by the minimal area and statistical method. In each plot, the aboveground and underground biomass and litter were collected. Soil sampling was performed in the plots and the measurement of carbon sequestration was conducted in the laboratory. Soil samples were collected from two layers of 0-15 and 15-30 cm and their carbon was measured. The three study rangelands were compared using a One-Way ANOVA analysis, and the results showed that the amount of carbon sequestration in the rangeland reclaimed with perennial rainfed alfalfa (36.8 ton / ha) after 4 years was around 1.25 fold higher than the medium grazing rangeland (29.27 ton / ha) and 1.71 fold as compared with the degraded rangeland (21.54 ton / ha). These results indicate that reclamation of degraded rangelands causes to achieve land conservation goals and increase the ability of the ecosystem for carbon sequestration.
Kazem Saedi; farhang ghasriani; Ali Ashraf Jafari; mohamad fayaz
Volume 24, Issue 3 , October 2017, , Pages 676-684
Ali Asghar Naghipour borj; Jamaladdin Khaeddin; Hosein Bashari; Majid iravani; Pejman Tahmasebi
Volume 23, Issue 3 , January 2017, , Pages 442-453
Abstract
The structure and composition of plant communities are mainly affected by fire and grazing, especially in arid and semiarid rangelands. This study aimed to investigate the role of fire and grazing on soil seed bank characteristics (density, diversity and species richness) in semi-steppe rangelands of ...
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The structure and composition of plant communities are mainly affected by fire and grazing, especially in arid and semiarid rangelands. This study aimed to investigate the role of fire and grazing on soil seed bank characteristics (density, diversity and species richness) in semi-steppe rangelands of Central Zagros. A stratified random sampling was used to collect the data from 12 sites with one and five years after the last fire, and with long term light and heavy grazing history. Soil samples were collected in the autumn by auger from 0-5 and 5-10 cm from the soil surface, and the samples were cultivated in the greenhouse. All the germinated seeds were identified and counted for a 6-month period. The results showed that the one year after fire treatment under both light and heavy grazing resulted to a significant decrease in density, richness, and diversity of the soil seed bank. The richness and diversity of soil seed bank in the five-year after fire treatment and under light grazing pressure increased significantly compared to its control site. According to the results, the soil seed bank in 5 to 10 cm from the soil surface did not vary statistically under fire and grazing pressure, indicating the role of soil depth in reducing the impact of fire and grazing. Overall, it can be concluded that the grazing management after a fire event has a key role in vegetation restoration through its effects on the soil seed bank.
Aezam Khosravi Mashizi; Gholamali Heshmati; Najmeh Faryabi
Volume 21, Issue 4 , March 2015, , Pages 571-579
Abstract
Negative and positive interactions among plants have important role for species coexistence and community diversity. The strength and direction of the interaction effect may change with environmental disturbances such as grazing and fire. This study was aimed to evaluate the effects of environmental ...
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Negative and positive interactions among plants have important role for species coexistence and community diversity. The strength and direction of the interaction effect may change with environmental disturbances such as grazing and fire. This study was aimed to evaluate the effects of environmental disturbances such as fire and grazing on interactions between shrubs and herbs in rangelands of Goghar Bafte. Hence, beneath 20 dominant species of Artemisia aucheri and 20 open patches, a quadrate of 20 cm×20 cm was plotted and the variation in the biomass, richness and vegetation cover of herbs were measured in regions under exclosure, fire and grazing. Results showed that biomass and vegetation cover of herbs were increased by shrub presence because of positive interaction between shrubs and herbs inside exclosure. Although the facility of shrubs was reduced by grazing and fire, its rate was not equal in both places. Under grazing, interaction between shrubs and herbs remained positive but shrubs were severely damaged by fire and the interaction between species altered from positive to negative. The overall conclusion is that fire plays a more important role in changing the interaction between shrubs and herbs.
Kazem Saedi; Adel Sepehri; Mohammad Pesarakli; Hosein Gharedaghi; Reza Azizinejad
Volume 21, Issue 3 , December 2014, , Pages 518-529
Abstract
In most Iranian rangelands, continuous grazing begins with melting snow and continues until the beginning of snow. This study was conducted to evaluate the effects of continuous grazing system on a number of morphological attributes of Bromus tomentellus and Ferula haussknechtii during 2010-2011 in Saral ...
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In most Iranian rangelands, continuous grazing begins with melting snow and continues until the beginning of snow. This study was conducted to evaluate the effects of continuous grazing system on a number of morphological attributes of Bromus tomentellus and Ferula haussknechtii during 2010-2011 in Saral Rangelands of Kurdistan Province. The 30-year exclosure was selected as control area inside the Saral Research Station. In different growth stages, the morphological attributes including the shortest and longest basal area diameter, the shortest and longest canopy diameter, and the height of 10 plants were measured. The annual yield of 30 plants of each species in each year was clipped and weighed to determine forage consumption intensity. All data were subjected to statistical analysis in a completely randomized design using combined analysis. Mean comparisons were performed using Duncan’s Multiple Range Test. Continuous grazing caused to the increase of basal area diameter and canopy diameter of B. tomentellus significantly; however, the height varied in two studied treatments, depending on the year. The three studied morphological attributes of F. haussknekhtii were affected drastically by continuous grazing. In this species, basal area diameter was more affected by the conditions of the year. In both species, ungrazed plants used seasonable rainfall more efficiently as compared to the grazed plants.
Fatemeh Salarian; Jamshid Ghorbani; Nosrat Allah Safaeian
Volume 20, Issue 1 , June 2013, , Pages 115-129
Abstract
Grazing animals affect rangeland vegetation structure and function directly and indirectly. These effects can be assessed in exclosures. In this study, the vegetation composition and some vegetation indices (functional groups, biomass, species diversity and richness) were compared in an exclosure (livestock ...
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Grazing animals affect rangeland vegetation structure and function directly and indirectly. These effects can be assessed in exclosures. In this study, the vegetation composition and some vegetation indices (functional groups, biomass, species diversity and richness) were compared in an exclosure (livestock excluded for about 10 years) and grazed areas in Chahar Bagh rangeland in Golestan province. The percentage of canopy cover, stone and gravel, bare ground, litter and the biomass were estimated in quadrates of 1 m2. Results showed that there were 34 species common in both areas while 7 and 11 species were restricted to exclosure and grazed areas, respectively. Results of t-test showed that exclosure significantly increased the percentage of canopy cover of some desirable species such as Agropyron intermedium, A. trichophorum, Festuca ovina. Also, the percentage of canopy cover of hemicryptophyte, grasses, forbs, and perennials significantly increased in exclosure area. Moreover, Simpson diversity index and species number significantly increased in exclosure. The biomass of grasses and total biomass also significantly increased from grazed area to exclosure. According to the results, exclosure for less than ten years could cause some changes in vegetation of this rangeland.
Maryam Nikan; Hamid Ejtehadi; Mohammad Jangju; Farshid Memariani; Hajar Hasanpour; Fariba Noadoost
Volume 19, Issue 2 , September 2012, , Pages 306-320
Abstract
Livestock grazing is one of the most influencing factors on the rangeland community structure and composition, which can also change the vegetation diversity. The main aim of this research was to survey the flora and plant biodiversity at three rangeland sites, being used under different grazing intensities, ...
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Livestock grazing is one of the most influencing factors on the rangeland community structure and composition, which can also change the vegetation diversity. The main aim of this research was to survey the flora and plant biodiversity at three rangeland sites, being used under different grazing intensities, Baharkish, Quchan, Iran. Three sites were systematically selected along a spatial gradient of low, moderate and high grazing intensity, and 20 quadrates were randomly established within each site. Species composition, abundance and canopy cover were recorded within the quadrates. Simpson and Shannon diversity and Carmago and Smith & Wilson evenness indices were measured for each site. Floristic studies led to the identification of 156 plant species belonging to 34 families. The floristic composition of the area was strongly dominated by the Irano-Touranian elements. Shannon and Simpson diversity indices were significantly higher under the moderate than the low and heavy grazing intensity sites and the lowest diversity was significantly recorded for the heavy grazing site. Evenness indices did not significantly differ between the low and moderate grazing sites, but it was significantly lower under the high grazing site. In conclusion, proper livestock grazing is necessary for preservation of species diversity in the semiarid rangelands; Moderate grazing maintained the species diversity while light and sever grazing reduced or even eliminated some sensitive plant species.
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.
Mohammad hosein Hadi Tavatory; Ahmad Akbarinia; Mahmood Khosravifard
Volume 15, Issue 3 , January 2008, , Pages 395-402
Abstract
The performances of Shal sheep breed were investigated in sukling and grazing periods in 2006.with 61 lambs utilized ewes milk 105 days of ages. They had grazed the pastures of Alfalfa-Bromus and Atriplex , and aftermath of barley and wheat respectively. Daily gain of lambs were measured ...
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The performances of Shal sheep breed were investigated in sukling and grazing periods in 2006.with 61 lambs utilized ewes milk 105 days of ages. They had grazed the pastures of Alfalfa-Bromus and Atriplex , and aftermath of barley and wheat respectively. Daily gain of lambs were measured in each periods. Data were analyzed through factorial model and by completely random design. Results indicated that nutrition periods were significantly different (p<0.01) but the factors of sex of lamb, sex period and covariate of initial weight of lamb had not significant(p>0.05). Sukling period had the highest daily gain(182±6 gr/day) . Atriplex and aftermath of barley and wheat had the least performances (42±10 and 68±4 g/day, respectively).This result proves that Atriplex pasture like Alfalfa-Bromus pasture and aftermath of barley and wheat can supply maintenance requirement of lamb. It can be utilized as a source of roughage for grazing intermittence in semi-arid regions.
Naser Baghestani Maybodi; Mohammad taghi Zare; Jalal Abdollahi
Volume 13, Issue 4 , February 2007, , Pages 337-346
Abstract
Study over vegetation on grazed and ungrazed rangelands is significant for range managemen, this the effects of 2-decade exclusion on vegetation of steppic rangelands in Nir range research station were studied. Three 7.5-hectare experimental plots were selected inside and outside of the exclosure. Exclosure ...
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Study over vegetation on grazed and ungrazed rangelands is significant for range managemen, this the effects of 2-decade exclusion on vegetation of steppic rangelands in Nir range research station were studied. Three 7.5-hectare experimental plots were selected inside and outside of the exclosure. Exclosure site had not been grazed from 1986 to 2004. The adjacent site was continuously grazed at the same time. Cover estimated on quadrates and forage yield were measured by clipping and weighting method. Data were analyzed by t-test method. Results showed that cover, density and yield of Salsola rigida and Stipa barbata increased significantly inside exclosure (p<0.01), but it was not significantly different in Artemisia sieberi (p>0.05).Cover, density and yield of Scariola orientalis , Launaea acanthodes and Noaea mucronatawere greater in grazed area, but only the yield of first species, density of second species and cover and density of third species were significantly high (p<0.05). Two-decade protection from grazing showed that vegetation trend is very slow in arid rangelands.