Rostam Moslempour; Reza Yari; Seyedeh Mahboubeh Mirmiran
Volume 31, Issue 4 , January 2025, , Pages 347-362
Abstract
Background and objectives: Desert ecosystems usually receive less attention in carbon sequestration studies due to their low vegetation cover and limited carbon sequestration. However, since more than a third of the earth's surface covers 55% of the total area of Iran and more than 50% of the area of ...
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Background and objectives: Desert ecosystems usually receive less attention in carbon sequestration studies due to their low vegetation cover and limited carbon sequestration. However, since more than a third of the earth's surface covers 55% of the total area of Iran and more than 50% of the area of South Khorasan province, so they can be a significant carbon storage place. This research was conducted with the aim of investigating the carbon sequestration by six desert species: Calligonum polygonoides, Seidlitzia rosmarinus, Artemisia sieberi, Stipagrostis pennata, Salsoa richteri and Zygophyllum eurypterum in the rangeland of Ferdows.Methodology: In this Study, 30 plots of four square meters were randomly established in Calligonum polygonoides, Seidlitzia rosmarinus, Zygophyllum eurypterum and Salsoa richteri and in Artemisia sieberi and Stipagrostis pennata habitats, 30 plots of two square meters were randomly established and the canopy percentage and plant density were estimated in each plot. Vegetation cover and plant density were estimated in each plot. In the same plots, the soil profile was dredged down to a depth of 70 cm under the canopy, and the soil sample was taken and transported to the laboratory. By estimating the percentage of soil organic carbon (using the Walkley-Black method) and bulk density of the soils (using the paraffin method), the amount of soil carbon sequestration was finally measured. The data was used in the form of a completely random design, and Tukey's test was used to compare the means at the five percent probability level. The Shapiro-Wilk and Bartlett tests were used to check whether residual value variances were normal and homogeneous. The data obtained from the results of the experiments were analyzed using R software.Results: In general, the results showed that the highest amount of soil organic carbon was observed in Salsoa richteri and Artemisia sieberi habitats and the lowest amount was observed in Seidlitzia rosmarinus habitat. The highest amount of bulk density was observed in Calligonum polygonoides habitats. The results of the analysis of variance showed that the effect of the habitat on soil carbon sequestration is significant (p<0.01) and the amount of this effect is moderate to high (ηp2 between 0.10 and 0.47). The highest and lowest amount of carbon sequestration was observed in Zygophyllum eurypterum (28.66 tons per hectare) and Seidlitzia rosmarinus (12.80 tons per hectare habitats, respectively. Also, in terms of the percentage of vegetation, a significant difference was observed between habitats. The highest and lowest of vegetation cover percentage was obtained in Zygophyllum eurypteru (36.84%) and Seidlitzia rosmarinus (10.15%) habitats, respectively. Seidlitzia rosmarinus habitat had the lowest amount of soil organic carbon and also the highest percentage of vegetation, and compared to other plants, it produced the lowest amount of carbon sequestration. The highest and lowest plant density was obtained in the Stipagrostis pennata and Zygophyllum eurypterum habitats, respectively. Despite the high organic carbon in the soil of its habitat, Salsoa richteri plant also had low carbon sequestration due to the low density and percentage of vegetation cover. The results of correlation analysis show that there is a positive and significant relationship between vegetation percentage and carbon sequestration (p<0.01), but no significant relationship was observed between plant density and carbon sequestration (p>0.05).Conclusion: The amount of carbon sequestration was different depending on the percentage of vegetation and there was a positive and significant relationship between the percentage of vegetation and the amount of carbon sequestration, while no relationship was observed between the amount of vegetation density and carbon sequestration. So, in this study, Zygophyllum eurypterum habitat produced the highest percentage of vegetation cover and carbon sequestration, and Seidlitzia rosmarinus habitat had the lowest percentage of vegetation cover and carbon sequestration. Therefore, the vegetation percentage parameter can be used to estimate carbon sequestration. In other words, in the habitats that have bushy and shrubby plants, it is possible to estimate the amount of carbon sequestration based on the canopy percentage.
morteza Khodagholi; Razieh Saboohi; Alireza Eftekhari; Mina Bayat
Volume 31, Issue 4 , January 2025, , Pages 363-381
Abstract
Background and purpose:Increasing awareness of the environment and efforts for sustainable management of natural resources require study and monitoring in different time scales and places. Continuous changes should be considered as an inseparable part of any ecosystem. As natural ecosystems, rangelands ...
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Background and purpose:Increasing awareness of the environment and efforts for sustainable management of natural resources require study and monitoring in different time scales and places. Continuous changes should be considered as an inseparable part of any ecosystem. As natural ecosystems, rangelands are not exempt from this issue. So that rangeland monitoring is necessary in the sense of continuous investigation of these lands with regard to the ecological importance, economic functions and constant changes of these resources. Access to such data is extremely important both for national planning and for the use of rangelands, and it provides the basis for the use of advanced facilities such as remote sensing. Based on this, in order to monitor the trend and intensity of changes in vegetation cover and soil indicators of rangelands for 4 years at the Goorab site located in Isfahan province, it was evaluated and monitored.Materials and methods:The site of Goorab Fereydoonshahr Isfahan is located 230 kilometers west of Isfahan city and 35 kilometers west of Fereydoonshahr city. Plant factors including canopy cover of plant species and production rate of plant species and percentage of dead leaves were evaluated. Evaluation was done in the first year by random-systematic method and in the following years systematically with sufficient number of samples and appropriate distribution of samples in the plant type determined at the time of rangeland preparation. Soil sampling was done in theResults:The results showed that the 4-year average vegetation canopy cover percentage of Goorab site is about 42.2%, and the highest and lowest coverage is 59.4% in 1398 and 31.6% in 1400, respectively. The production rate is 1374.2 kg of dry matter per hectare. The production, like the canopy cover percentage, shows a lot of changes during the 4-year evaluation at the Goorab site, so that in 2019, the production reached 1957 kg per hectare, and in 2021, it decreased by 50% compared to 2019 to 955.7 kg per hectare. The results of the correlation and regression test also showed that the amount of precipitation in the growing season had the highest correlation with the amount of crown cover and production of plants in the region.Conclusion:Considering the importance of rangelands, both in terms of production and in terms of environmental values and services they provide to the society, studying the changes of rangelands in terms of the aforementioned factors and knowing the factors of those changes will be an effective help in developing a basic management plan and sustainable use of rangelands.
Mahnaz Amini; Hosein Bashari; Mohammad Taghi Feizi
Volume 31, Issue 2 , August 2024, , Pages 129-148
Abstract
Background and objectivesVarious environmental and managerial stresses are severely threatening wetland ecosystems in Iran. The Gavkhouni Wetland, one of the largest and most strategically significant wetlands in the central plateau of Iran, faces numerous challenges. Given its unique ecological importance ...
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Background and objectivesVarious environmental and managerial stresses are severely threatening wetland ecosystems in Iran. The Gavkhouni Wetland, one of the largest and most strategically significant wetlands in the central plateau of Iran, faces numerous challenges. Given its unique ecological importance and the diverse plant habitats surrounding it, studying the vegetation in this area is crucial. Understanding the various conditions of the plants, including dominant families, geographical distribution, biological forms, and conservation status, is essential for any conservation, management, or ecological research activities in this region. MethodologyThe study area encompasses the upper reaches of the Zayandehrud River in Isfahan Province, covering 50,000 hectares with elevations ranging from 1,470 to 2,533 meters above sea level. This region has an arid climate characterized by saline soils, including solonchaks, marshy areas, and sandy soils. The average annual temperature at Gavkhuni Wetland is 17.6 degrees Celsius, with total annual precipitation measuring 91 millimeters. According to the Ambrothermic curve, the area experiences a prolonged dry period from April to November. Field surveys were conducted using 1:25,000 scale topographic maps from early October to November 2021. During these surveys, plant samples were collected, pressed, dried, and identified at the herbarium of the Natural Resources Department of Isfahan University of Technology, with consultation from experts and reliable scientific sources. This research resulted in a comprehensive list of plant species, detailing their scientific names, families, genera, life forms, geographical distribution, and conservation statuses. ResultsThe study identified 100 plant species from 16 families and 65 genera in the region, with 27 species possessing medicinal and industrial properties. The Amaranthaceae family, with 31 species, and the Asteraceae family, with 14 species, collectively constitute 45% of the vegetation cover. Other prominent families include Poaceae with 10 species and Fabaceae with 9 species. In terms of life forms, therophytes dominate at 40%, followed by hemicryptophytes at 23%. Geographically, 71% of the identified species belong to the Irano-Turanian floristic region. Despite the ecological challenges faced by the area, its diverse topography and edaphic factors have fostered significant species diversity. ConclusionGavkhuni Wetland's flora is highly sensitive to climate and management practices. Despite facing severe biological constraints, the region exhibits relatively robust plant diversity. Inadequate management of the Zayandehrud watershed, particularly in Gavkhuni Wetland, has resulted in declining groundwater levels and increased aridity, threatening many plant species with drying, pest infestations, shrub encroachment, and overgrazing. Continued adverse conditions, exacerbated by climate change, pose a significant threat to the region's flora.
Saeed Abdollahzadeh; Marzieh Rezaie; Rasoul Mahdavi
Volume 31, Issue 2 , August 2024, , Pages 204-218
Abstract
IntroductionThe distribution of plants in different habitats is influenced by environmental and edaphic conditions. Identifying the relationship between soil factors and vegetation, as well as the specific soil characteristics in which these species are found, is one of the important goals of this research. ...
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IntroductionThe distribution of plants in different habitats is influenced by environmental and edaphic conditions. Identifying the relationship between soil factors and vegetation, as well as the specific soil characteristics in which these species are found, is one of the important goals of this research. Taking steps in this direction will help prevent habitat destruction and facilitate the restoration of damaged areas. Let me know if you need any further adjustments! Materials and methods The study identified three representative areas using the physiognomic-systematic method, focusing on the habitat of Ferula assafoetida L. Areas with less than 15% coverage were classified as low-density, those with 15-30% coverage as medium-density, and areas with more than 30% coverage as high-density. In each representative area, eight transects of 1000 meters were systematically established and positioned perpendicularly to each other. To account for slope variations in sampling, quadrat sampling along the transects was employed. The plot size was determined using the minimum level method, with species density measured in 2 x 2 square meter plots across a total of 240 plots. To prepare soil samples, two soil profiles were dug at a distance of 500 meters along each transect, resulting in a total of 48 profiles from which soil samples were collected at depths of 0 to 30 cm. In each representative area, three transects of 1000 meters were placed perpendicularly, with ten sampling bases spaced 100 meters apart along each transect. The collected samples were transported to the Water and Soil Laboratory of Hormozgan University for analysis. The amount of gum collected from each base was measured using a digital scale with an accuracy of 0.001 grams. A comparison of the production of this plant gum was conducted across the different habitats. The changes in edaphic factors in representative areas were analyzed using SPSS software with the GLM test, revealing low density at 15.8 bases per hectare, medium density at 27.8 bases per hectare, and high density at 46.9 bases per hectare of Ferula assafoetida L. Results In the areas with low density, the soil acidity level was measured at 7.4, while in the medium-density area, it was 7.8, and in the high-density area, it reached 8. These results indicate that soil acidity is higher in densely populated areas and lower in areas with low density, suggesting that Ferula assafoetida is more compatible with alkaline soils. As soil acidity increases, the density of this plant decreases. The analysis of density changes in relation to organic matter percentage showed that organic matter has a direct effect on plant density; as organic matter increases, so does the density of the plant. Conversely, when the soil has low organic matter content, the density of Ferula assafoetida declines. Additionally, the comparison of average potassium levels revealed that the low-density area had the lowest potassium content, while the high-density area had the highest. The combined levels of calcium and magnesium were also lowest in the low-density area and highest in the dense Angozeh habitat. Furthermore, the number of Ferula assafoetida bases per unit area increased in regions with higher sand content, whereas the number of bases decreased in clay soils. This plant is not compatible with saline or acidic soils. ConclusionUnderstanding the ecological needs and performance of plant species is essential for implementing remedial activities in dry and desert ecosystems. Bestak city, located in Hormozgan province, is home to numerous Anghuzeh plantations, which have the potential to produce gum, generate currency, and provide significant economic value for local communities. The region is characterized by elevations ranging from 1900 to 2500 meters. This species exhibits a greater geographical distribution in areas with sand, silt, and high acidity, with increased density and decreased distribution in clay-rich areas. According to the findings, it appears that this plant thrives in light soils.
Zahra Jaberalansar; Babak Bahreininejad; Alireza Eftekhari; Masoud Borhani
Volume 30, Issue 3 , January 2024, , Pages 424-440
Abstract
Background and objectivesThe study of vegetation changes under habitat protection conditions has a significant role in rangeland management. The studies confirm that permanent changes in rangelands in terms of plant composition, canopy cover, and forage production are influenced by ecological and management ...
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Background and objectivesThe study of vegetation changes under habitat protection conditions has a significant role in rangeland management. The studies confirm that permanent changes in rangelands in terms of plant composition, canopy cover, and forage production are influenced by ecological and management factors. This research was conducted to investigate and monitor the plant vegetation indices of semi-steppe rangelands of central Zagros for five years (2016-2020) at the Zayandehrud watershed management research site (Isfahan province). Methodology Vegetation sampling was performed by a systematic random method in each exclosure and grazed site during 2016-2020. Vegetation characteristics, including the percentage of canopy cover of species, the percentage of gravel, bare soil, and litter were determined in each plot. For this purpose, four 100-meter segments were used. Then, ten plots (with 1 x 1-meter dimensions) were established with the same distance. In total, vegetation cover was measured in 80 plots of one square meter in exclosure and grazed sites. To calculate rangeland production, ten samples of each plant species were collected, and their canopy cover percentage was measured. After drying and weighing the samples, by establishing regression equations between the canopy cover percentage and the weight of the dried samples, the amount of production of plant species was determined separately for growth form and palatability class. Rangeland's condition was also evaluated according to the four-factor method and by scoring the factors of soil, vegetation, plant composition and age classes, and plant vigor. After collecting the data in Microsoft Excel, the variance analysis for the vegetation traits was done as a completely random design in a factorial format. This was done through the GLM (General Linear Model) method. Tukey's test investigated vegetation traits mean comparison in MINITAB 16 software. ResultsThe analysis of variance showed a significant difference between vegetation indices, including total canopy cover and production, separately for growth form and palatability class. This was in the exclosure and grazed sites during the assessment period. The average percentage of canopy cover in exclosure sites during different years was 26.7%, 13.7%, 25.84%, 33.74%, and 13.33%. In grazed sites, it was 22.33%, 12.65%, 27.09%, 30.9%, and 11.59%, respectively. Total production at the exclosure site during different years was 624.26, 349.86, 556.79, 894.54, 664.53 kg/ha. Production at the grazed site was 456.45, 243.85, 455.6, 605.47, and 323.44 kg/ha, respectively. The highest values of canopy cover and production belonged to 2019, which was a wet year based on meteorological indices. The lowest canopy cover and production were assigned to 2017 (a drought year). The highest amount of litter was found at the exclosure site. The highest percentage of bare soil and annual plant canopy cover was obtained from the grazed site. The highest percentage of canopy cover and production in the exclosure site belonged to Stipa hohenackeriana. At the grazed site, Hedysarum criniferum and Stipa hohenackeriana accounted for the highest canopy cover and production, respectively. According to the four-factor method, the rangeland condition at the disclosure site was fair in 2016, 2018, and 2019 and poor in 2017 and 2020. At the grazed site, the rangeland condition was fair in 2018 and 2019 and poor in the rest of the years. Conclusion The comparison of vegetation parameters inside and outside the exclosure shows the good condition of vegetation inside the exclosure. It also shows the effectiveness of the exclosure in rangeland rehabilitation. Balanced livestock grazing on the vegetation caused no significant difference between vegetation characteristics, such as canopy cover in the exclosure and grazed sites. Continuous evaluation and monitoring of rangelands through creating a regular database of vegetation indicators and investigating their changes under different managements. This investigation of their relationship with climatic factors can provide the necessary background for fundamental rangeland planning and management.
Mehri Dinarvand; Mohammad Fayaz; Hashem Keneshlo; Kourosh Behnamfar; Sajad Alimahmodi sarab; farhad khaksarian
Volume 29, Issue 1 , February 2022, , Pages 99-111
Abstract
Measuring the diversity and identifying plant vegetation traits and functional groups and classifying them, in addition to helping to accurately identify the vegetative capacity of the area, helps us to understand the vegetation response of the area to disturbances and presence. Potentially resistant ...
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Measuring the diversity and identifying plant vegetation traits and functional groups and classifying them, in addition to helping to accurately identify the vegetative capacity of the area, helps us to understand the vegetation response of the area to disturbances and presence. Potentially resistant species with similar or invasive traits help. The purpose of this study was to investigate and evaluate the vegetative status of the region, the trend of changes and evaluation of the second sequence of dust centers in Khuzestan after planting seedlings in different ways. Functional groups (PFTs) were used. To evaluate the changes in the vegetation of the area by field survey, 15 transects of 100 meters with distances of 50 meters were systematically randomly selected (the first transect was randomly selected and the rest with a defined distance of 50 meters). Due to the uniformity of plant species composition and the absence of environmental effects, a total of 180 fixed plots with dimensions of 1 square meter (location recording with GPS device) were installed. The results of a recent study in three areas of the dust center in the southeast of Ahvaz showed that in selected areas, various irrigation methods along with rainfall will cause significant changes in the percentage of cover (frequency) and the number of species from 2017 to 2020. Functional groups in the Tovayel region with surface irrigation (Faro) In 2020, nine groups were identified, in Bagan region with tanker irrigation and hole digging with seven excavators, and in Hanitieh region with tanker irrigation and hole digging seven functional groups. The results of T-test analysis also showed that there is a significant difference between the average of the two values of all indicators, including the diversity of Shannon and Simpson in March 2017 and March 2020 for all three regions so diversity indicators raised since number of species and cover increased.
Masoud Barzali; Mojgansadat Azimi; Mohammad Abdolhosseini; Abdolrahim Lotfi
Volume 29, Issue 1 , February 2022, , Pages 133-144
Abstract
The various services that we obtain directly and indirectly from the natural environment are referred to as ecosystem services. The purpose of these services is to communicate with human welfare in four categories of services: provision, support, regulation and culture. The purpose of this study was ...
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The various services that we obtain directly and indirectly from the natural environment are referred to as ecosystem services. The purpose of these services is to communicate with human welfare in four categories of services: provision, support, regulation and culture. The purpose of this study was to investigate the supply of soil conservation services at different land uses and also to compare their amount. InVEST model was used for this research. To calculate soil retention, this model estimates soil erosion potential using the Modified Soil Erosion Equation (RUSLE) and sediment retention rate based on sediment delivery ratio. Therefore, the required input information of the model including biophysical table and maps of digital elevation model, rain erosion, soil erodibility, vegetation and land use were prepared with the help of ArcGIS 10.4 software and entered into the model in the form of raster maps. The results of this study showed that among different land uses, forests and rangeland with good and average condition had the highest soil conservation and the lowest amount was related to barren lands, residential areas and poor pastures. The results also showed that the highest rate of soil conservation occurs in the east and southeast and upstream of the basin and factors such as reduced vegetation and soil type have contributed to the intensification of erosion in this area. The results of this research can be useful in land management programs and appropriate decision making for rangeland management.
Somayeh Naseri
Volume 27, Issue 4 , December 2020, , Pages 732-741
Abstract
Carbon sequestration in soil and plant tissues is an effective way for climate change mitigation in the world. In this study, the effect of biomechanical operations (gabions which planted by Agropyrum elongatum) on carbon sequestration were examined in the rangelands of Kardeh basin, Mashhad and compared ...
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Carbon sequestration in soil and plant tissues is an effective way for climate change mitigation in the world. In this study, the effect of biomechanical operations (gabions which planted by Agropyrum elongatum) on carbon sequestration were examined in the rangelands of Kardeh basin, Mashhad and compared with natural rangelands and non- established waterways. In each treatment, Sampling from soil in two depths, above-below biomass of dominant species and litter were done by a systematic - randomly method and analyzed for carbon stocks. Carbon sequestration in biomechanical treatment during 1996- 2014 has been calculated by subtracting carbon stocks in this treatment and non- established waterways. Generally, total carbon stocks in biomechanical operation (above- below biomass, litter and soil up to 50 cm depth) is 16.23 ton/ha and carbon sequestration in this treatment during these years is 5.69 ton/ha. Also, carbon stocks in natural rangelands and non- established waterways is 54.07 and 10.61 ton/ha respectively. Overall, implementation of biomechanical practices in Kardeh basin in addition to soil conservation and restoration of vegetation,has improved the economic value of eroded lands in terms of carbon stocks and sequestration.
Leila Bakhshandehmehr; Mohammadreza Yazdani; Reza Jafari; Saeid Soltani
Volume 27, Issue 3 , October 2020, , Pages 463-484
Abstract
Research on the environmental controllers in plant communities is one of the research fields for many ecologists. Identifying the factors affecting the vegetation cover in the arid regions is the first step to recognize the destructive factors, which inhibit the growth and development of vegetation. ...
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Research on the environmental controllers in plant communities is one of the research fields for many ecologists. Identifying the factors affecting the vegetation cover in the arid regions is the first step to recognize the destructive factors, which inhibit the growth and development of vegetation. In the current study, using the structural equation modeling method and Partial Least Square – Structural Equation Modeling (PLS-SEM), climatic and pedological variables that affecting the vegetation cover in steppe rangelands of Zayandehrood basin of Isfahan province were identified and modeled. According to the results, soil clay content, maximum runoff height on the soil, temperature, and dryness of the environment are the most important variables affecting the quantity and quality of vegetation in the rangelands of the Zayandehrud basin. Besides, the role of climatic factors is more than soil factors in the distribution of vegetation in the region. The model presented in this research has good accuracy and high flexibility for modeling ecological phenomena.
Kazem Dashtakian; Mohammad Khosroshahi
Volume 11, Issue 4 , September 2019, , Pages 383-408
Mohammad Khosroshahi; Majid Hasani; Shirin Mohammadkhan; Abbas Attarpour; Seyed Aziz Karami; Abolfazl Khalilpour; Ebrahim Farahani; Hamidreza Abbasi
Volume 10, Issue 4 , August 2019, , Pages 409-428
Hosein Arzani; Jalal Abdollahi; Mehdi farahpour; Mojganolsadat Azimi; ali Ashraf Jafari; Mahmoud Moalemi
Volume 12, Issue 3 , August 2019, , Pages 263-286
farhad Azhir; Naser Ansari; Valiollah mozafarian
Volume 12, Issue 1 , August 2019, , Pages 81-96
Hesam Ahmadi Birgani; Parisa Ravan
Volume 26, Issue 2 , July 2019, , Pages 487-499
Abstract
Researchers and target groups studying the vegetation are seeking to answer the question “what ground indicators determine the establishment and distribution of vegetation types and vegetation communities of a basin and which landforms can best determine the boundaries of each ...
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Researchers and target groups studying the vegetation are seeking to answer the question “what ground indicators determine the establishment and distribution of vegetation types and vegetation communities of a basin and which landforms can best determine the boundaries of each plant type or community?”. In this regard, the Gardaneh-Ghooshchi basin, overlooking the Urmia Lake in West Azarbaijan Province was selected. Vegetation cover map, land capability evaluation map, geology map, soil map, geomorphology map, and land units map, were precisely and accurately generated based on the technical methods and field surveys. The multinomial logistic regression method was used to compare, describe and accurately predict vegetation types with different landforms. The results showed that homogeneous units with a quantitative value of 0.432 had the highest impact, followed by geomorphology, geology, and soil with quantitative values of 0.389, 0.351 and 0.156, respectively, in the next rank. Therefore, slope, aspect, and elevation (physiographic characteristics of the basin) have a more effective role in the distribution of vegetation, which could be used before ground monitoring as a baseline map in mountainous areas.
Bahram Gholinejad; Arian Farhadi; Parviz Karami
Volume 26, Issue 1 , June 2019, , Pages 260-269
Abstract
Collection of appropriate quantitative data is necessary for proper management and planning in rangelands. One of the ways to access this information is choosing the appropriate methods of sampling and determining the appropriate length of transect for vegetation cover measurement. Therefore, this study ...
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Collection of appropriate quantitative data is necessary for proper management and planning in rangelands. One of the ways to access this information is choosing the appropriate methods of sampling and determining the appropriate length of transect for vegetation cover measurement. Therefore, this study was conducted in 2016 in Ariz rangelands located in the northwestern of Sanandaj city. For this purpose, transects with a length of 20, 50, 100, 150, 200, 300 and 400 meters, each with four replications were established perpendicular to slope and parallel to slope in the vegetation type of Bromus tomentellus - Festuca ovina. The 400-m transect was considered as a control for calculations. The obtained data from sampling were compared by ANOVA. The obtained results from different transect lengths were also compared by (E%) 2×T factor. The mean comparisons of vegetation cover percentage of transects were performed using t-student test. According to the results of this study, the transects of 20, 50, 100 and 150m length showed a significant difference with the control transect (400 m) in terms of accuracy index ((E%) 2 × T). However, there was no significant difference among the transects of 200, 300 and 400 meters length for the accuracy index. Therefore, the application of 200-meter transect is recommended regarding the cost and time.
Mahshid Souri; Mohammad Fayaz; Nadia Kamali; Saeedeh Nateghi
Volume 25, Issue 4 , February 2019, , Pages 911-922
Abstract
The main objective of this research was to evaluate vegetation changes and soil indicators in the Kalat Sadat Sabzevar area under rangeland management practices. Vegetation factors including plant species production, vegetation cover, cover percentage, litter percentage, plant ...
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The main objective of this research was to evaluate vegetation changes and soil indicators in the Kalat Sadat Sabzevar area under rangeland management practices. Vegetation factors including plant species production, vegetation cover, cover percentage, litter percentage, plant species density, and rangeland condition and trend were measured at the exclosure site and adjacent control site. The assessment was conducted using a random-systematic method with a sufficient number of samples and appropriate distribution of samples at the time of rangeland readiness. The rangeland trend was determined on the basis of two methods, and rangeland condition was determined based on the four-factor method. Soil sampling was carried out at a depth of 20 cm. A total of 12 soil samples were taken from the first, second and third transects (exclosure site), as well as fourth, fifth and sixth (control site). Data were analyzed by the independent t-test using SPSS software. According to the obtained results, the highest canopy cover percentage in terms of palatability belonged to class II plants (19.37), and in terms of vegetative form belonged to the perennial plants (16.2). Also, the largest share of production in the exclosure site and grazing site was related to shrubs and perennial grasses, respectively. The results showed that clay, silt, lime, organic carbon, nitrogen and electrical conductivity were significantly different at 5% level between the exclosure and grazing sites, but there was no significant difference between acidity and phosphorous. Therefore, exclosure could be recommended as an improvement practice to be carried out in more areas of the region.
Hamid Amirnejad; Kamal Ataie Solout; Ardavan Zarandian
Volume 25, Issue 1 , April 2018, , Pages 216-226
Abstract
Bamou national park in Iran has many environmental functions such as ecosystem regulation functions. The ecosystem function of water regulation by forest and rangeland ecosystems includes seasonal water flow regulation, water supply for various uses, treatment and storage of ...
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Bamou national park in Iran has many environmental functions such as ecosystem regulation functions. The ecosystem function of water regulation by forest and rangeland ecosystems includes seasonal water flow regulation, water supply for various uses, treatment and storage of water. In this study, effects of dominant vegetation in the Bamou National Park (including Astragalus gossypinus, Astragalus susianus, Ebenus stellate, Amygdalus scoparia, Amygdalus lycioides, Scariola orientalis and Scariola orientalis) on the runoff control were estimated in four soil erosion types using Justin method. According to the results, effects of vegetation on the runoff height reduction were estimated to be 1.28, 0.71, 0.71 and 1.19 centimeter in four erosion types of E1 to E4, respectively. In addition, the economic value of water conserved in the underground aquifers in the current area of park was estimated to be 68.105 billion rials and 1.792 million rials per hectare in 2012.
Mohammad Khosroshahi; Morteza Abtahi; Mohammadtaghi Kashki; Sakine Lotfinasab; Fateme dargahian; Zohre Ebrahimi
Volume 24, Issue 2 , July 2017, , Pages 404-417
Abstract
So far, different statistics have been presented for the area of deserts in the world and Iran by individuals and organizations. The reason for this difference is mainly due to the disagreement among experts in providing a comprehensive definition of desert and factors affecting its formation. In this ...
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So far, different statistics have been presented for the area of deserts in the world and Iran by individuals and organizations. The reason for this difference is mainly due to the disagreement among experts in providing a comprehensive definition of desert and factors affecting its formation. In this paper, the factors of natural environment, such as climate, vegetation, geomorphology, soil, geology and hydrology, whose effects are directly or indirectly involved in the emergence and general appearance of the desert, were investigated. Therefore, to identify and define the desert ranges in terms of the study factors, a number of indicators were defined, based on which desert zones were identified for each factor individually. Then, digital maps were produced by overlaying the layers. Results showed that the largest area of desert regions in Iran with a surface of 693690 and 567711 square kilometers is influenced by climatic and vegetation factors, respectively, and the least area of desert regions with a surface area of 208041 and 272,258 km is affected by the geological and geomorphologic factors, respectively. From the aspect of soil science, the area of desert regions in Iran covers a surface of 514930 km2. The total area of deserts was calculated to be 9007293 square kilometers, which accounts for 55 percent of the total area of Iran.
savan shahrokhi; Mahshid Souri; javad moetamedi; Alireza Eftekhari
Volume 24, Issue 1 , May 2017, , Pages 98-109
Abstract
Global warming has devastating effects on the lives of organisms, causing damage to natural ecosystems, floods, droughts and climatic and ecological imbalance. Resonance effects of greenhouse gases in the atmosphere as a result of carbon dioxide concentration causes warming, melting polar ice caps, ...
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Global warming has devastating effects on the lives of organisms, causing damage to natural ecosystems, floods, droughts and climatic and ecological imbalance. Resonance effects of greenhouse gases in the atmosphere as a result of carbon dioxide concentration causes warming, melting polar ice caps, massive flooding, and deforestation. Biological carbon sequestration is soil and plants' ability to absorb carbon dioxide from the atmosphere and store it in plant and soil. Therefore, it is a method that helps to reduce atmospheric carbon and to mitigate the consequences of climate changes. In this project, the effects of restoration rangeland practices (contour furrow) on carbon sequestration were investigated in Khalifan region of Mahabad. For this purpose, in each study site (contour furrow and control), four 100-m transects were established. Along each transect, five plots spaced 20 m apart were set up systematically. At the beginning and end of each transect, a profile was excavated at two depths (0-15 and 15-30 cm). Soil and plant samples were transferred to the laboratory. Plant biomass was measured in all plots by cutting and weighing method. Carbon sequestration rate was determined for each of the samples. The data were analyzed by ANOVA and T-test. The results indicated that the highest rate of carbon sequestration in the study sites belonged to the litter. The results demonstrated that the rate of carbon sequestration in both biomass and soil in contour furrow site was higher in comparison with control site. This can be due to the positive effect of contour furrow practice on the amount of participation storage in soil, run off and erosion control and increasing the vegetation.
Zahra Jafari; Hamid Nik Nahad Gharemakher; Samira mesri
Volume 23, Issue 4 , March 2017, , Pages 680-688
Abstract
This research was aimed to study the vegetation changes under grazing and non-grazing conditions during five years in order to evaluate vegetation improvement or destruction over time.The study of vegetation changes was carried out inside and outside the exclosure within the sample units. Each sample ...
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This research was aimed to study the vegetation changes under grazing and non-grazing conditions during five years in order to evaluate vegetation improvement or destruction over time.The study of vegetation changes was carried out inside and outside the exclosure within the sample units. Each sample unit consisted of two parallel transects with 20 quadrates. Within each quadrate, the canopy cover percentage and composition percentage of each species were estimated. The forage yield was measured by clipping and weighing using one-square-meter quadrates. No significant difference was recorded for the canopy cover of inside and outside the exclosure. Statistical analysis was performed in a completely randomized block design and no significant differences were found among the study years. However, significant differences were found for forage yield of inside and outside the exclosure. Therefore, the reduction in forage yield of outside the exclosure is directly related to the intensity of utilization. The life form of species was determined based on Raunkiaer's system. Hemicryptophytes was the dominant form in the study area. The results showed that although the exclosure caused to improve rangeland vegetation, the difference between inside and outside the exclosure was not significant. Generally, the results indicated that vegetation changes in the study area were slow and gradual and exclosure could not be considered as an improvement method in short-term. Direct human intervention is required for the restoration of rangelands, located in arid regions.
Leila Mostafavi; Gholamali Heshmati; hamid mostafalou
Volume 23, Issue 4 , March 2017, , Pages 785-799
Abstract
Range suitability assessment for different objectives is along with management principles and guarantees sustainable development. A considerable area of Golestan Province plains is covered with halophytes, grazed by different livestock including sheep. A study was done to assess the suitability of saline ...
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Range suitability assessment for different objectives is along with management principles and guarantees sustainable development. A considerable area of Golestan Province plains is covered with halophytes, grazed by different livestock including sheep. A study was done to assess the suitability of saline winter rangelands with dominant species of Halocnemum strobilaceum and Aleuropus lagopoides for sheep grazing. The F.A.O method in GIS environment was used in this research for Gomishan Plain, Golestan province, Iran. In the method, three criteria of vegetation, water and soil erodibility were used as the sub-models and constituted the final model components. For vegetation sub-model, vegetation types, cover percentage, forage production, range condition and trend and range capacity were determined. Distance from water resources, water quantity and quality were determined for water sub-model. For the soil erodiblity sub-model evaluated by the EPM model, slope, rock and soil sensitivity to erosion were determined. The final model of range suitability for sheep grazing revealed that 38.69 and 61.31 percent of the region were classified as low suitability and no suitability, respectively. Among all factors determined in sub-models, the distance from water resource was the most limiting factor for sheep grazing and forage production was the most reducing factor of range suitability. Finally, utilization of rangelands in the region could be improved by reducing grazing intensity and implementing range restoration practices.
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.
Abolfazl Rahmati Zadeh; Mostafa Jafari; Mostafa Karimian Eghbal
Volume 21, Issue 4 , March 2015, , Pages 580-590
Abstract
Identifying the border of saline lands is the first step to deal with the problem of salinity in these regions. This research was aimed to investigate the relationship between edaphic, climatic and vegetative factors in each habitat and its extension to other similar areas. In the current research, the ...
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Identifying the border of saline lands is the first step to deal with the problem of salinity in these regions. This research was aimed to investigate the relationship between edaphic, climatic and vegetative factors in each habitat and its extension to other similar areas. In the current research, the vegetation types were detected by Landsat satellite images. For this purpose, a soil profile was dug in each vegetation type and where water was found, samples were analyzed. In addition, a number of soil profiles were dug in areas without vegetation. Results showed that half of the studied vegetation types grew on saline soils and the other half grew on non-saline soils. The soil of the study area was classified as saline and alkaline soils. Seidlitzia sp. and Aeluropus sp. were identified as the most and least resistant halophytes, respectively. Geological formations containing evaporite deposits (Neogen), Qom formation deposits, little precipitation, Qom salt dome, saline water flowing in the region and geomorphological position were the factors increasing the salinity of the study area.
Morteza Hoseini |Tavasol; Hosein arzani; manoocher farajzadeh asl; Mohamad Jafari; sasan babayee kafaki; asghar kohandel
Volume 22, Issue 4 , March 2015, , Pages 615-624
Abstract
This research was aimed to monitor the vegetation changes in the rangelands of Alborz province during 2000-2011 using satellite images as well as determining its relationship with climatic factors including average rainfall, temperature, and relative humidity. According to the results, the highest NDVI ...
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This research was aimed to monitor the vegetation changes in the rangelands of Alborz province during 2000-2011 using satellite images as well as determining its relationship with climatic factors including average rainfall, temperature, and relative humidity. According to the results, the highest NDVI was recorded for Taleghan followed by Savojbolagh and Karaj, and then Eshtehard and Karaj with less significant difference. Based on the obtained model, the rainfall of November, December, January, February, and average annual rainfall had the most positive impact on the growth of range plants, while other factors including temperature and relative humidity had no significant relationship with the vegetation of the study period. According to the trend of vegetation changes, the amount of vegetation has been reduced after year 2000 and it has increased again in 2011.
Vahideh abdollahi; Farhad zolfaghari; Mitra Jabari; Mohamad rafie dehghan
Volume 22, Issue 4 , March 2015, , Pages 658-672
Abstract
This research was aimed to investigate the effects of crescent pond structure on soil and vegetation properties in the Saravan rangelands. For this purpose, two treatments including crescent pond and control treatment were determined. For each treatment, the density, canopy cover percentage, and litter ...
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This research was aimed to investigate the effects of crescent pond structure on soil and vegetation properties in the Saravan rangelands. For this purpose, two treatments including crescent pond and control treatment were determined. For each treatment, the density, canopy cover percentage, and litter were estimated by random-systematic sampling using five transects of 100 m and 50 plots. Two soil samples were taken along each transect from 0-30 cm depth and soil physico-chemical properties were measured. Data were analyzed statistically. According to the obtained results, significant differences were found for all vegetation parameters between the crescent structure and control treatment, indicating the positive effect of crescent structure on vegetation parameters. The results of soil properties indicated reduced soil salinity; however, the organic matter, potassium, and pH showed no difference between the two regions. According to the results, due to the climatic conditions of the study area, longer time is needed to achieve better results.