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.
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. Jafari; A. Tavili; M. Rostampour; M. A. Zare Chahouki; J. Farzadmehr
Volume 62, Issue 2 , October 2009, , Pages 197-211
Abstract
This study was carried out to investigate the effective environmental factors in the distribution of vegetation in Zirkouh rangelands of Qaen. After delimitation of the study area, sampling of soil and vegetation were performed using randomized- systematic method. Vegetation cover was recorded by using ...
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This study was carried out to investigate the effective environmental factors in the distribution of vegetation in Zirkouh rangelands of Qaen. After delimitation of the study area, sampling of soil and vegetation were performed using randomized- systematic method. Vegetation cover was recorded by using Braun-Blanquet combined abundance-cover scale in each sample. Within each sample, one profile was dug and soil samples being taken at 0-20 cm and 20-100 cm depths. Physical-chemical characteristics were determined include texture, lime, organic matter, soil moisture content, saturation moisture, EC and pH. Five vegetation groups were identified after the application of TWINSPAN method and were named after the characterizing species as follows: Salsola richteri-Aelorupes littoralis; Zygophyllum eurypterum-Haloxylon ammodendron; Artemisia sieberi-Zygophyllum eurypterum; Ammodendron persicum-Stipagrostis pennata; Artemisia aucheri-Amygdalus scoparia. The results of PCA showed that environmental factors best related with the distribution of this vegetation are texture, lime, organic matter, soil moisture content, saturation moisture, elevation and slope.
H. Mohammadi; H. R. Karimzadeh; S. J. Khajeddin
Volume 62, Issue 1 , June 2009, , Pages 125-137
Abstract
Study of soil and plant relationships is nessesery for ecological- based and appropriate management. The objective of this study is to determine the influence of edaphic properties on Haloxylon persicum growth and also, indentifing growth limiting soil properties for saxaul. The study was performed through ...
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Study of soil and plant relationships is nessesery for ecological- based and appropriate management. The objective of this study is to determine the influence of edaphic properties on Haloxylon persicum growth and also, indentifing growth limiting soil properties for saxaul. The study was performed through the stratified random sampling and 3 sites were selected as follow: planted strong saxaul, planted weak saxaul, rangeland without saxaul. Then 6 samples of Haloxylon persiocum were selected in each region, meanwhile, plant parameters including canopy cover area, canopy cover perimeter, the smallest and the largest canopy cover diameter, average of canopy cover diameter, height, basal area and diameter were considered. Also, 9 profiles in sites were sampled and the followiong properties: pH, SP, EC, Ca+Mg, Cl-, CO3--,HCO3-, SO4--, gravel, CaCO3, CaSO4, organic matter, clay, silt, sand, available phosphorous, Na+, K+, CEC, SAR, ESP, PSS, PSW and TDS were measured. Ordination method was used for data analysis. Accordiong to the results, plant parameters have significant diffirences in saxaul sites with the same age. Soil physical characteristics including soil texture and chemical characteristics such as organic matter, available phosphorous, CEC, salinity, CaSO4 and CaCO3 content showed the highest influence on saxaul growth parameters.
