Hasan Ghelichnia; Hamidreza Mirdavoodi; Ali Cherati Araie
Volume 30, Issue 2 , September 2023, , Pages 264-285
Abstract
Background and objective Today, predictive models of plant species distribution play a crucial role in assessing, restoring, protecting, and developing rangeland ecosystems. It is one of the most important tools to learn about species distribution and habitat suitability. This research determined ...
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Background and objective Today, predictive models of plant species distribution play a crucial role in assessing, restoring, protecting, and developing rangeland ecosystems. It is one of the most important tools to learn about species distribution and habitat suitability. This research determined ecological factors affecting plant composition, species response to environmental factors changes, and the potential of the target species in the study area using multivariate analysis. Based on this, with a better understanding of the ecological niche of this plant, the necessary recommendations can be made for using the species in rangeland improvement programs in similar habitats. Methodology Vegetation sampling was done by a systematic-random method during 2016-2018.Vegetation studies were carried out, including the percentage of canopy cover of species and the density of species inside the plots. Also, the percentage of litter, bare soil, stones, and pebbles was determined in each plot. For this purpose, five transects with the same distance were used. Then, six plots (with 2 x 2 meters dimensions) were established on each with the same distance. To investigate the effect of environmental factors on the distribution of the studied species, three soil samples were taken from each plot at a depth of 0 to 30 cm, and their physical and chemical properties were measured in the laboratory. Climatic factors such as average rainfall and annual temperature were collected using data from weather stations near the study area. To investigate the relationship between effective and significant environmental variables and vegetation and to choose the appropriate linear and non-linear method, DCA was performed on the vegetation data, and the gradient length was determined. A generalized additive model predicted plant species' response to environmental changes. Canoco software version 4.5 was used to analyze the data in this section. Results The results of conventional comparative analysis showed that environmental factors such as clay percentage, geographical direction, acidity, sand, saturated moisture percentage, organic matter percentage, average annual temperature and soil lime percentage in the studied habitats, respectively 10.3, 4.4, 3.3, 3.3, 1.6, 1.4, 1.4 and 1.3 percent of the variance in plant composition, play an important role in changes in vegetation in the habitats.It showed that A.specigera species respond to the amount of phosphorus, percentage of organic matter, electrical conductivity, percentage of nitrogen, percentage of clay, percentage of organic carbon, and altitude. This is following the monotonic decrease model. The response pattern of this species to the percentage of silt, percentage of sand, average annual temperature, average annual rainfall, the direction of slope, acidity, potassium, the apparent specific gravity of soil, percentage of soil saturation and percentage of slope follows the bell model (Unimodal) and limit its growth optimum for each of these factors is 21%, 60%, 16°C, 400mm, for eastern and southern slopes, 8, 650mg/liter, 1.4g/cm3, 39% and 40-50%. Conclusion The generalized incremental model provides valuable information to determine species' ecological needs. This information can be used in vegetation management and rangeland improvement operations in similar areas using the data from this research. Forage production is high in the studied species, suggesting its potential for increasing rangeland vegetation cover.
Hassan Ghelichnia; Hamidreza Mirdavoudi; Ali Cherati
Volume 29, Issue 4 , January 2023, , Pages 513-529
Abstract
Understanding the ecological characteristics of plant species and how they respond to environmental factors provides information necessary for vegetation management and rangeland management. Therefore, in the present study, the ecological needs of the species Salsola kerneri (Wol) Botsch with emphasis ...
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Understanding the ecological characteristics of plant species and how they respond to environmental factors provides information necessary for vegetation management and rangeland management. Therefore, in the present study, the ecological needs of the species Salsola kerneri (Wol) Botsch with emphasis on determining the ecological factors affecting vegetation changes and investigating the response of these species to ecological factors changes using Canonical Correspondona Analysis (CCA) and Generalized Additive Models (GAM) in Mazandaran province were discussed. Data were analyzed using SPSS17 and CANOC 4.5 software. The results showed that S.kerneri showed a significant response to some of environmental factors in its habitat. The response pattern of S.kerneri along the Ec, pH and Tnv (Lime) followed the monotonic increase model and increased with increasing values, abundance and percentage of vegetation. Therefore, with the increase of these factors in a certain range, the coverage percentage of this species increases. The response of this species along the pH of soil followed the monotonic increase model and by increasing this factor, the presence and percentage of vegetation decreased. The response of this species along the organic matter (%) of organic carbon (%), nitrogen (%) and litter%) followed the monotonic decrease model and by increasing this factor, the presence and percentage of vegetation decreased. The response pattern of S.kerneri along the clay (%),soil specific gravity, Altitude of sea, mean annual temperature, potassium (ppm) and phosphorus (ppm) followed the unimodal model and its optimum growth rate for these factors were 11%, 1.1 g/cm3,13C°,1700m,12.5°C, 700 ppm and 5 ppm respectively. It grows in lands with low to relatively high slopes, but it has more abundance in slopes of 40-50%. The highest cover percentage of this species in the eastern slopes and the lowest in the northeastern slopes. The stone (%), sand (%) and silt (%) response also followed the bimodal model. The study of this species response curve along the slope of topographic and soil factors provided valuable information to determine the ecological needs of this species that can be considered in rangeland improvement operations in similar areas.
Masoud Borhani; Zahra Jabrolansar; Hamidreza Mirdavoodi
Volume 29, Issue 2 , July 2022, , Pages 111-125
Abstract
Understanding the ecological characteristics of plant species and how they react to environmental factors provides the necessary information for vegetation management and rangeland improvement. In the present study, the ecological needs of sainfoin (Onobrychis melanotricha Boiss.) ...
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Understanding the ecological characteristics of plant species and how they react to environmental factors provides the necessary information for vegetation management and rangeland improvement. In the present study, the ecological needs of sainfoin (Onobrychis melanotricha Boiss.) were studied with emphasis on environmental factors affecting vegetation changes, and the response of this species to changes in ecological factors was investigated using the Canonical Correspondence Analysis (CCA). Data collection was performed in 2018 in 19 study sites in the west and south of Isfahan province. In each site, the vegetation sampling was performed by random-systematic sampling method in 30 plots of one square meter, located along 3 200-meter transects, and soil sampling was done from a depth of 0-30 cm in each site. Data were analyzed using SPSS17 and CANOC4.5 software. Using a generalized additive model with Poisson error distribution for each of the environmental variables showed that environmental factors including height, clay percentage, rainfall, organic matter percentage, phosphorus, and sand percentage, and the average annual temperature significantly affect (p<0.01) vegetation. This species is distributed on semi-deep to deep soils with medium to semi-heavy textures. This species is distributed on semi-deep to deep soils with medium to semi-heavy textures. The optimal altitude range for the growth of this plant was 1600-3200 meters above sea level, and the optimal rainfall for this plant was 370 mm. Overall, the results of this study had an acceptable efficiency in determining the ecological needs of the species, which can be considered by natural resource managers in vegetation management and rangeland improvement operations in similar areas.
reza yari; Gholamali Heshmati; Hamed Rafiee
Volume 28, Issue 4 , November 2021, , Pages 745-758
Abstract
Assessment of the potential ecological and natural capacity of each area with proper planning can lead to sustainable and continuous utilization of natural areas. By increasing the population and psychological pressures resulting from the bustle of cities, ecotourism has become doubly ...
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Assessment of the potential ecological and natural capacity of each area with proper planning can lead to sustainable and continuous utilization of natural areas. By increasing the population and psychological pressures resulting from the bustle of cities, ecotourism has become doubly important as one of the ways to reduce the pressures on people. The development of ecotourism to conserve natural resources should be commensurate with the natural and social potential of the region. Due to the importance of conserving natural resources, the purpose of this study is to evaluate the ecotourism potential of Chaharbagh summer rangelands in Golestan province based on the FAO limiting method and using GIS. The factors assessed include two ecological categories (climate, altitude, slope, soil, water resources, distance to attraction places, value attractive vegetation) and infrastructure (distance to city, amenities, roads, and access routes). The results showed that the total area of the region is 25.36% (2249.29 ha) with medium potential and competence (S2), 28.65% (2542 ha) with low potential and competence (S3), and 45.98% (4079) hectare lacks ecotourism competence and potential (N). The results also showed that water resources, soil, slope percentage, vegetation attraction value, access routes, and distance to attractions are factors that reduce the potential and merit of tourism and altitude factors, distance to city and facilities, welfare as well as climate (temperature) are factors that increase the potential and merit of tourism. Chaharbagh rangelands have suitable facilities and potentials in terms of tourism, and observing the principles of tourism and preserving natural resources, in addition to creating employment and income for the residents of the region, can help the protection and sustainable development of the region.
Zahra Jaberalansar; Masoud Borhani; Babak Bahreininejad; Hamidreza Mirdavodi
Volume 28, Issue 3 , October 2021, , Pages 551-563
Abstract
Understanding the ecological characteristics of plant species and how they respond to environmental factors provides the information needed to manage vegetation and restore rangeland ecosystems. The aim of this study was to determine the environmental factors affecting the habitat of Krascheninnikovia ...
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Understanding the ecological characteristics of plant species and how they respond to environmental factors provides the information needed to manage vegetation and restore rangeland ecosystems. The aim of this study was to determine the environmental factors affecting the habitat of Krascheninnikovia ceratoides (L.) species and its response to changes in ecological factors in the rangelands of Isfahan province. Accordingly, canopy cover and density of K.ceratoides and the associated species were measured in 19 ecological sites using random systematic sampling method. In each site, climate, physiography and soil factors were identified. Canonical Correspondence Analysis (CCA) and Generalized Additive Models (GAM) using CANOC4.5 software were used to investigate the vegetation relationship with environmental factors. The results showed that the response pattern of K. ceratoides along the gradient of absorbable potassium follows the incremental model. Conversely, the response of this species along the gradient of sand percentage, average annual temperature and rock and gravel percentage has followed a decreasing model and with increasing these factors, the percentage of canopy cover has decreased. The response pattern of K. ceratoides along the changes of the amount of absorbed phosphorus, the percentage of gypsum and the altitude of the sea, follows the bell model (Unimodal), and its optimal growth limit for these factors is 10 mg kg-1, 6.4% and and 2250 meters. The study of K. ceratoides species response along the gradient of topographic, soil and climate factors provided valuable information to determine the ecological needs of this species that can be considered in vegetation management and rangeland improvement operations in similar areas.
Maryyam Molaei; Ardavan Ghorbani; Mehdi Moameri; Asgar Hossainzadeh
Volume 27, Issue 3 , October 2020, , Pages 545-560
Abstract
The purpose of this research was to model the spatial distribution of Artemisia fragrans and A. chamaemelifolia in Ghezelozen-Aghdagh elevation profile rangelands of Khalkhal city. For modeling, information about species and habitat factors such as topography, soil, and climatic factors ...
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The purpose of this research was to model the spatial distribution of Artemisia fragrans and A. chamaemelifolia in Ghezelozen-Aghdagh elevation profile rangelands of Khalkhal city. For modeling, information about species and habitat factors such as topography, soil, and climatic factors were used, and habitat distribution modeling was performed by a logistic regression method. All parameters affecting the distribution of species were prepared as a raster map. Then, by combining the maps of the factors affecting the species distribution, the distribution map was predicted through the logistic regression method. The results showed that the most important factor in spatial prediction of A. fragrans in the region was altitude and with each meter of elevation, the presence of this species decreased by 0.88%. The results also showed that the presence of A. chamaemelifolia species was inversely related to altitude, mean temperature, and soil potassium. The Kappa index was used to determine the agreement between the prediction models with ground truth. The kappa coefficient was 0.91 for A.fragrans and 0.62 for A. chamaemelifolia, which indicates the excellent agreement of the model with reality. According to the prepared forecast map, A. fragrans and A. Chamaemelifolia species can be considered for lowland and higher altitude rangelands.
Masoud Borhani; Zahra Jabeolansar
Volume 26, Issue 3 , September 2019, , Pages 741-753
Abstract
Correlation between vegetation and environmental variables is the most important issue related to the structure and function of rangeland ecosystems. Environmental factors such as climate, topography, and soil can alter the dynamics of plant communities. In this study, the effects ...
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Correlation between vegetation and environmental variables is the most important issue related to the structure and function of rangeland ecosystems. Environmental factors such as climate, topography, and soil can alter the dynamics of plant communities. In this study, the effects of environmental factors on vegetation of some rangeland sites in Semirom region of Isfahan province were evaluated. Sampling was carried out at 52 rangeland sites in a random-systematic way. At each location, 40 plots of one square meter were placed along four transects, and the percentage of vegetation cover in each plot was measured using ocular-estimate method. The grid layers of bioclimatic and topographic variables were prepared in ArcGIS 10.1 and values for each range site were extracted. Soil samples were collected from range sites and some physical and chemical properties of the samples were measured. Redundancy Analysis (RDA) was used to evaluate the relationships between environmental factors and the plant species cover. Cluster analysis was also used to group the studied range sites based on environmental factors. According to the results, annual mean temperature, isothermality, mean temperature of wettest quarter, soil texture, pH, organic matter, and elevation were identified as the most important ecological factors affecting plant species cover.
Aydin Faraji; Hamed Joneidi Jafari; Bahram Gholinejad
Volume 25, Issue 2 , August 2018, , Pages 427-437
Abstract
This study aimed to determine the most important ecological factors affecting the canopy cover of Astragalus gossypinus in some parts of semi-steppe rangelands of the Kurdistan province. Field survey was carried out in three areas of Kurdistan meadows including Dezli, Narran, and Murvarid saddle. The ...
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This study aimed to determine the most important ecological factors affecting the canopy cover of Astragalus gossypinus in some parts of semi-steppe rangelands of the Kurdistan province. Field survey was carried out in three areas of Kurdistan meadows including Dezli, Narran, and Murvarid saddle. The number of plots, according to the characteristics of the vegetation and other environmental factors, was calculated to be 6 for Dezli, 3 for Naran, and 4 for Murvarid saddle. The plots of vegetation were sampled in a random-systematic manner in an area of 1 × 1 m and along two transects of 100 m. Soil sampling in each plot was performed with three replications and at the depth of 0 to 50 cm at and between the base of the plants. Factors such as soil, clay, silt, sand, gypsum, lime, electrical conductivity, pH, phosphorus, calcium, magnesium, stones and pebbles, nitrogen, carbon, and potassium were measured. For the analysis of soil and vegetation, ANOVA, and in order to determine the effect of different environmental factors on the vegetation cover, multiple regressions were applied. To determine the most important factors affecting the canopy cover of vegetation, principal component analysis was also used. The results showed that the factors including carbon, potassium, pH, magnesium, phosphorus, calcium, lime, nitrogen, clay, sand, average annual rainfall, and the canopy cover percentage were significantly different at the level of 1%; while, the factors such as gypsum and electrical conductivity were not significant among the different habitats. The regression results showed that the factors including lime, height, and precipitation justified the changes of cover 25%, 12% and 7%, respectively.
Hamid reza Mirdavoodi; Hojat... Zahedi; Masud Shakoei; Javad Tourkan
Volume 13, Issue 3 , February 2006, , Pages 201-211
Abstract
The initial step of each phenomenon is complementary recognizing and understanding of its relationship with other effecting and affecting phenomena. Regarding rangeland vegetation as the first chain of nutrition in rangeland's ecosystems, recognition of its homogeneous areas and vegetation type classification ...
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The initial step of each phenomenon is complementary recognizing and understanding of its relationship with other effecting and affecting phenomena. Regarding rangeland vegetation as the first chain of nutrition in rangeland's ecosystems, recognition of its homogeneous areas and vegetation type classification seems necessary. The present study was carried out in order to determination the most effectiveness ecological factors on vegetation types using Multivariate data analyzing. For that vegetation type was determine of type using GPS together with field survey and drawing map of the areas on the 1/50000 scale. Some data layers for each of vegetation type including density and cover percentage, climate, the mean elevation classes, mean annual rainfall, the mean slop, mean annual temperature, land types and Geographical aspect of the areas were collected and analyzed using Statistica program package and the method of factor analysis. The results of factor analysis shows that between applied variable, three main variables including climate, land types, and Geographic aspect with Eigenvalues of 82.8 are the most effectiveness ecological factors on vegetation types. Using cluster analysis rangelands classified in to 22 groups of Markazi province. the groups were confirm by Discriminate Analysis method.
Khosro Mirakhorlo; Zein ... Hosseini
Volume 13, Issue 2 , February 2006, , Pages 127-138
Abstract
Estimating rangelandsۥ production is one of the range management tools. This requires detailed information about the present available forage of the rangelands. The assessment of the parameters is difficult and cost-intensive using clipping method. Therefore, new estimating methods are required. We ...
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Estimating rangelandsۥ production is one of the range management tools. This requires detailed information about the present available forage of the rangelands. The assessment of the parameters is difficult and cost-intensive using clipping method. Therefore, new estimating methods are required. We estimated available forage using remote sensing data in the production model that it extracted from ecological parameters and remote sensing data. For quantifying evaluation of vegetation cover stratified random sampling and transect sampling methods were selected. Plot size calculated from “minimal area and species curve” method. Overall, 28 transects (50m) one transect in each site that contain 280(1m2) sample plots were measured. Modeling performed using NDVI index, animal density and effective ecological factors (altitude, slope, aspect, precipitation, temperature and evaporation) on rangelandsۥ yield. After analyzing of ecological factors of Damavand region, some ineffective factors omitted. Finally three factors namely slope, precipitation and NDVI index were entered in the model for calculating the available forage in the study area. The calculated amount of average standard predict value of forage model is 38% and its standard deviation value is 97%. They show that the validation of model for predicting of forage is fairly acceptable.