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.
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.