Document Type : Research Paper
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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 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.
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