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.
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.
Seyedeh Habibeh Hoseini; Gholamali Heshmati; Mehdi Mirza; Parviz Karami
Volume 26, Issue 2 , July 2019, , Pages 447-458
Abstract
This research was conducted to evaluate the environmental factors affecting functional characteristics (biomass, density, regeneration, cover%, basal area and species richness) of Ferula haussknechtii in Saral rangelands of Kurdistan. After determining three altitude classes (1850, ...
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This research was conducted to evaluate the environmental factors affecting functional characteristics (biomass, density, regeneration, cover%, basal area and species richness) of Ferula haussknechtii in Saral rangelands of Kurdistan. After determining three altitude classes (1850, 2250 and 2650 m), a systematic-random sampling was performed to measure aboveground biomass, cover percentage, height, basal area, and density of Ferula haussknechtii with 1.5-m2 plots along transects. In each plot, a soil sample was taken from 0-30 cm soil depth. Soil texture, CaCo3, acidity, electrical conductivity, nitrogen, potassium, phosphorus, and sodium were measured in the laboratory. Analysis of variance of data was done using a randomized complete design with R software, and also CCA was used to compare the relationship between species and environmental factors. The results showed that aboveground biomass, vegetation percentage, height and density of Ferula haussknechtii increased with increasing altitude, while the basal area of this species decreased. The green biomass, cover percentage, basal area and height of this species were positively correlated with nitrogen, carbon, potassium, silt and clay and negatively correlated with acidity, phosphorus and sand. The results also showed that due to the impact of this valuable species on the soil stabilization, forage supply and production of active ingredients, altitude, nitrogen, carbon, clay and silt were the most effective factors in establishing this species.
Hamidreza Mirdavoudi; Vahid Etemad; Mohammadreza Mohajer; Ghavamoddin Zahedi Amiri
Volume 25, Issue 1 , April 2018, , Pages 116-128
Abstract
Grazing is one of the most important factors in providing environmental conditions for change in species composition, structure and function of ecosystems. West oak woodlands of Iran as a valuable ecosystem are not immune from this threat. Therefore, it is essential to study the various ...
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Grazing is one of the most important factors in providing environmental conditions for change in species composition, structure and function of ecosystems. West oak woodlands of Iran as a valuable ecosystem are not immune from this threat. Therefore, it is essential to study the various aspects of this phenomenon in these ecosystems. The aim of this study was to examine the effects of relative grazing intensity on vegetation characteristics in an oak forest dominated by Quercus brantii. The research was conducted in Dalab Park, located in Ilam province, west of Iran. Information of vegetation, soil and other environmental variables were collected from 53 sample plots (16×16 m) using the random sampling method in various disturbances classes. Two-way indicator species analysis was used for classification of the ecological groups. Indicator species analysis was used to determine indicator species in each class and canonical correspondence analysis to identify the relationship between factors and the plant groups studied. The results showed that the grazing as well as soil, topographic factors and the light reaching to the forest floor was identified as the most influential factors on plant composition. Grazing explained the highest percentage of variance (11.2%) in floristic composition and caused an increased frequency of non-palatable species and resistant species to grazing and soil compaction as well as increasing of annuals including Bromus tectorum, Picnomon acarna, Minuartia picta, Rochelia disperma, Holesteum umbellatum, Lophocloa phlorides, and Valerianella vesicaria. These species were identified as invasive species based on density, abundance, and available resources. On the other hand, it seems that the spread of palatable species such as Vicia sativa,Trifolium physodes, Lens cyanea, and Lathyrus inconspicaus in the moderate grazing site indicates the role of balanced livestock grazing in maintaining the proper species composition in rangelands.
Fazel Amiri
Volume 23, Issue 2 , September 2016, , Pages 395-383
Abstract
In order to determine the attractiveness of plants for apiculture, an area was selected in the summer rangelands of Freidan region. To identify the plants and determine the apicultural potential, sampling was conducted randomly along three transects of 200 m and 30 plots when 10-20% of dominant species ...
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In order to determine the attractiveness of plants for apiculture, an area was selected in the summer rangelands of Freidan region. To identify the plants and determine the apicultural potential, sampling was conducted randomly along three transects of 200 m and 30 plots when 10-20% of dominant species were in the flowering stage. The attractivity index (AI) of each plant was determined by direct observation of the films taken from the study area, and averaging the number of bees and the time each bee spent on the flowers. The attractivity index (AI) of plant species was determined using ordination method, classified in four classes as excellent, good, fair and poor. Our results showed that a high number of visitor bees and a high time spent on species were the common characteristics of the plants classified in the class I. In the study area, Compositae, Labiatae, Umbelifera, and Cruciferae were the most important plant families used by bees. Of the 88 species in the region, 70 species, forming the dominant vegetation cover of poor rangelands, are used by bees.
Amir Hosein Parsamehr; Mohammadreza Vahabi; zahra Khorovani
Volume 22, Issue 1 , June 2015, , Pages 194-203
Abstract
Vegetation cover is one of the most important factors for ecosystem sustainability; thus, recognizing and understanding factors affecting the establishment and distribution of vegetation communities are necessary. This study was aimed to determine the relationship between vegetation and soil parameters ...
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Vegetation cover is one of the most important factors for ecosystem sustainability; thus, recognizing and understanding factors affecting the establishment and distribution of vegetation communities are necessary. This study was aimed to determine the relationship between vegetation and soil parameters of Ardestan rangelands, Isfahan Province. Primarily, the vegetation types were distinguished in the field using physiognomic method. Plot size was determined applying minimal area method. The number of plots was determined using statistical method. Systematic randomized sampling was used and performed along three transects of 100 m length. Ten plots of 6m2 were established along each transect at 10-meter intervals. Three soil profiles were dug in each area and soil samples were taken at a depth of 0-150 cm to study 21 soil factors. The results of factor analysis showed that among variables studied, 17 variables were the most effective factors on vegetation types of the study area. To determine the effect of environmental factors on the establishment of vegetation, canonical correspondence analysis was used applying CANOCO software. Ordination results showed that environmental factors such as soil texture, lime, potassium and electrical conductivity had the most important role in the establishment and expansion of plant communities in the study area.
Ardovan Ghorbani; Ali Asghari
Volume 21, Issue 2 , August 2014, , Pages 368-381
Abstract
The relationship between the distribution of Festuca ovina and ecological factors such as topography, climatic and edaphic characteristics was investigated in 45 sites of Southeastern rangelands of Sabalan in Ardabil province.Within the determined sites, three large plots of ...
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The relationship between the distribution of Festuca ovina and ecological factors such as topography, climatic and edaphic characteristics was investigated in 45 sites of Southeastern rangelands of Sabalan in Ardabil province.Within the determined sites, three large plots of 10 × 10 m, 40 meters away from each other, were established along a 120–meter transect from lower slopes to highlands. The measurement of canopy cover parameters was performed in three plots with dimensions of 60 × 25 cm within the middle plot and the lower and upper plots were used as control. Different parameters including altitude, slope and aspect were calculated and averaged for three plots. In the middle plot, a soil profile was dug to a depth of 30 cm and soil samples were collected from two depths of 0-15 and 15-30 cm to measure soil parameters. Cluster analysis and principal components analysis (PCA) were used to classify the sites and the importance of parameters was determined by discriminate analysis (DA). Using multivariate analysis, the study sites were classified into four groups.The sites having high canopy cover percentage of F.ovina were classified in group 3, in which altitude, slope, and precipitation were higher than those of other groups, while temperature, salinity and pH were lower. This shows that this species is more compatible to higher altitudes and lower temperatures and dose not tolerate soil salinity. It is more compatible to a pH of 7.1 to 7.3. Organic matter, phosphorus and potassium will provide better conditions for growth. Results of principal component analysis showed that the two main components could explained 95% of the data variations, and the classification of sites using these two components confirmed the results of cluster analysis. According to the obtained results, the distribution of F.ovina was affected by several ecological factors including temperature, climate, soil, and aspect.
Jalal Abdollahi; Hossein Naderi; Mohammad Reza Mirjalili; Monireh sadat Tabatabaeezadeh
Volume 20, Issue 1 , June 2013, , Pages 130-144
Abstract
Understanding the behavior and action of plant species and their ecological relationships with environmental variables is essential as an important part of the information required in range improvement, rehabilitation and proper utilization of rangelands. In this research, the effects of environmental ...
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Understanding the behavior and action of plant species and their ecological relationships with environmental variables is essential as an important part of the information required in range improvement, rehabilitation and proper utilization of rangelands. In this research, the effects of environmental factors on quantitative growth characteristics of Stipa barbata were investigated by ordination method in rangelands of Nodoushan –Yazd. For this purpose, twenty five sites were identified using the vegetation map and field visits, and in each reference area 30 plots were established along 3 transects of 500 m with random-systematic sampling. Inside the plots, a list of existing species, canopy cover, number of species and production were recorded. Three soil samples were taken from 0–30 cm depth. Soil samples were pooled together to obtain a composite sample. Clay, silt, sand, organic matter, lime, pH, electrical conductivity, sodium, calcium and magnesium were measured. Topographic features such as slope, altitude and aspect, were also recorded, and the type of formation was determined using geological maps. The relationships between growth parameters of stipa barbata and environmental factors were determined using Canonical Correspondence Analysis (CCA) method. Results showed that there were significant correlations among canopy cover, density and yield with soil factors. According to the results, among soil factors, soil texture, pH, SAR, Ca+2/Na+, calcium carbonate (T.N.V) and gravel had the most influence on canopy cover, density and yield. The effect of topography variables on growth characteristics was not significant. A significant relationship was found between growth characteristics of S. barbata and the type of geological formation.
Azadeh Asrari; Gholam reza Bakhshikhaniki; Abalfazl Rahmatizadeh
Volume 19, Issue 2 , September 2012, , Pages 264-282
Abstract
In this research relationship between vegetation and salt soil in Qom province was studied. The study area situated in central Iranian which is about 14631 km2 with Salt Lake. In this study, first considered region condition including the geographical position, geological history, pedology and ...
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In this research relationship between vegetation and salt soil in Qom province was studied. The study area situated in central Iranian which is about 14631 km2 with Salt Lake. In this study, first considered region condition including the geographical position, geological history, pedology and climate. The aim of this study was assessment of plant communities of area and their relationship with soil. Primarily the vegetation types were distinguished at the field with physiognomic-floristic-ecologic method. The species data were gathered with stratifield random sampling method using the 10m by 10m quadrats recording the species covers, litter, bare soil, stone and gravel cover in the quadrat. In this study were considered 11 soil factors in 48 types of rangeland. Using cluster analysis was separated 13 plant communities in the region. To determine the effect of environmental factors on the establishment of vegetation was used CCA ordination method using software CANOCO. Ordination results showed that environmental factors such as electrical conductivity (EC), lime, sodium (Na), potassium (K) and calcium(Ca), are studied the most important role in the establishment and expansion of areas plant communities. Also plants of Chenopodiceae family compared with plants of Poaceae family have efficient mechanisms of salt tolerance. In salt lands gradual change of soil moisture, zoning of different species and vegetation types to come in parallel strips. Thus topography of the ground, although small, are the main factors of soil chemical and physical changes, and naturally caused the formation of specific habitat for various plant species.
Zohreh Mirdeylami; Gholam Ali Heshmati; Hosein Barani; Yalda Hematzadeh
Volume 19, Issue 2 , September 2012, , Pages 333-343
Abstract
Recognition of ecological factors affecting the establishment and distribution of plants is necessary and the use of multivariate analysis could be useful to achieve this purpose. In the current research, relationship among the most effective environmental parameters on distribution and establishment ...
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Recognition of ecological factors affecting the establishment and distribution of plants is necessary and the use of multivariate analysis could be useful to achieve this purpose. In the current research, relationship among the most effective environmental parameters on distribution and establishment of vegetation types of Kachik Watershed was studied by multivariate analysis method. After providing land unit maps, density and canopy cover percentage were measured in reference areas of each land unit. Random-systematic method was used and sampling was performed on 53 quadrates established on 19 transects with intervals of 150 m. Soil samples were taken from the depth of 0-30 cm and pH, EC and percentage of clay, silt and sand were measured. Six separate ecological groups were identified by cluster analysis. Results of principal component analysis revealed that aspect, slope, pH, EC, soil texture and Ca had the most effect on distribution of ecological groups with correlation coefficients of 0.98, 0.96, 0.93, 0.89, 0.82 and 0.81, respectively.
Hamid Torang zar; Qavam aldin Zahedi; Mohammad Jafari; Hojat ... Zahedi pur
Volume 18, Issue 3 , September 2011, , Pages 384-394
Abstract
The main objective of the present study was finding spatial relationship model of the plant species composition to physico-chemical soil variability, in north-west of Mighan Desert in Arak. According to the condition of the studied habitats, the study was based on a survey of three identified vegetation ...
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The main objective of the present study was finding spatial relationship model of the plant species composition to physico-chemical soil variability, in north-west of Mighan Desert in Arak. According to the condition of the studied habitats, the study was based on a survey of three identified vegetation types. Sampling method for vegetation study was randomized systematic. Quadrate size was determined for each vegetation type using minimal area method. Soils sample were taken from 0-20 and 20-100 cm depths. The measured soil factors included, EC, organic matter, texture, lime, gypsum, available moisture, pH, and soluble ions (Ca2+, Mg2+, Na+, Co32- , H-Co3, Cl-, So42). The classification of vegetation was analyzed by TWINSPAN and DCA methods. To determine the most edaphically effective factors in distribution of vegetation, PCA and CCA were applied. Three main vegetation groups were identified by TWINSPAN analysisand DCA. The result indicated that soil salinity, soil texture, lime, and soluble ions (Mg2+, So42) played the main role in the distribution of plant species.