sahar ghafari; Ardavan Ghorbani; mehdi moameri; Raoof Mostafazadeh; Mahmood Bidar lord; Azad Kakemami
Abstract
The aim of this study was to investigate the effects of topographic, edaphic, climatic and landscape metrices on the distribution of plant communities in the altitude gradient of Moghan-Sabalan rangelands in Ardebil province. To determine and study the ecological species groups, 28 sites and 840 one ...
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The aim of this study was to investigate the effects of topographic, edaphic, climatic and landscape metrices on the distribution of plant communities in the altitude gradient of Moghan-Sabalan rangelands in Ardebil province. To determine and study the ecological species groups, 28 sites and 840 one square meter sampling plots were samples by the random systematic method. To determine soil factors, soil samples were collected from each site from 0–15 and 15-30 cm depth and physicochemical parameters were measured at the lab. Using TWINSPAN, vegetation of the study area was classified and then PCA and CCA were used to investigate the relationship between species and environmental factors. According to TWINSPAN results, four ecological groups were identified. The first ecological group is located in the opposite direction of elevation, slope, rainfall and patch area gradients, and the same direction with pH, clay and dispersible clay (the first depth), bulk density, edge density and patch area (coefficient of variation). The second and third ecological groups are located in the interfaces of the first and fourth ecological groups in terms of plant composition and environmental conditions. These two groups prefer the middle elevations. The fourth ecological group at the end of the elevation, rainfall, slope, patch area and inverse direction of clay and dispersible clay (the first depth) and typically prefer high altitudes and light texture soils.
Bahram Gholinejad; Mohammad Jaffari; Mohammad Ali Zarechahuki; Hossein Azarniuand; Hassan Pourbabaei
Abstract
This research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in Saral rangelands of Kurdistan province. After selecting plant types as working area were done sampling from plant types and determined some of plants parameters ...
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This research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in Saral rangelands of Kurdistan province. After selecting plant types as working area were done sampling from plant types and determined some of plants parameters such as kind and number of plants and cover percentage. Various environmental factors such as topographic factors (slope, slope direction and elevation), soil physical factors (depths, soil texture, gravel and saturation moisture) and various chemical factors such as acidity, electrical conductivity, lime, gypsum percentage, organic material, nitrogen, phosphor and potassium) were measured and grazing intensity were considered as managerial factors. After collecting data, the Principal Component Analysis (PCA) was used to determine relationship between vegetation cover and environmental factors by PC-ORD software. The results showed that among various environmental and managerial factors affecting in plant distribution, soil depth, grazing intensity, elevation, sand, gravel and silt percentage have the highest correlation with Principal Component Analyses. These factors are the most effective factors on plants type distribution in rangeland ecosystems. Among effective soil factors on distribution of plant communities in this study, soil physical factors have greater impact than soil chemical properties. Physiographic factors including elevation and managerial factors including grazing intensity have considering effect on distribution of plant communities.
Mohammad Ali Zare Chahouki; Masoud Yousefi; Mohammad Jafari; Hossein Azarnivand; Marjan Shafizadeh Nasrabadi
Abstract
The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the ...
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The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the region were determined. Sampling method was randomized–systematic and within each sampling unit 3-5 parallel transects with 300-500 m length, each containing 30-50 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area; hence suitable quadrate size for different species was determined 1*2m–10*10m (2-100 m2). Soil samples were taken from 0-30 and 30-80 cm in starting and ending points of each transect. Measured soil properties included gravel, texture, available moisture, saturation moisture, organic matter, lime, gypsum, pH and electrical conductivity. To analyze environmental data, classification (using TWINSPAN) and ordination (using PCA, CCA) were used. The results indicated that soil salinity, texture and available water play the main role in distribution of plant species.
M.A Zare Chahouki; A Zare Chahouki; M Zare Ernani
Volume 63, Issue 3 , December 2010, , Pages 331-340
Abstract
The objective of this research was to study the relationships between edaphic and topographic factors with distribution of plant species. For this purpose, current study was conducted in Eshtehard rangelands of Tehran province. The sampling method was randomized–systematic and in each sampling unit, ...
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The objective of this research was to study the relationships between edaphic and topographic factors with distribution of plant species. For this purpose, current study was conducted in Eshtehard rangelands of Tehran province. The sampling method was randomized–systematic and in each sampling unit, three parallel transects with 750 m length containing 45 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area; hence suitable quadrate size for different species was determined 1*2m (2 m2). Soil samples from the beginning and end of each transect at two depths 0-30 and 30-80 cm were taken and the measured soil properties included gravel, texture, organic matter, lime, pH and electrical conductivity. To analyze the environmental data, PCA was considered. The results indicated that gravel, texture, EC and lime play the main role in the distribution of plant species.
