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.) ...
Read More
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.
shokoofeh Shokrollahi; Hamidreza Moradi; Ghasem Ali Dianati Tilaki; Zahra Jabeolansar
Volume 21, Issue 3 , December 2014, , Pages 541-548
Abstract
This study is focused on investigation of plant species distribution in relation to edaphic and physiographic factors. For this purpose, after the initial visit and selection of the study area, 23 land units were selected from overlaying the maps of slope, aspect and height using geographic information ...
Read More
This study is focused on investigation of plant species distribution in relation to edaphic and physiographic factors. For this purpose, after the initial visit and selection of the study area, 23 land units were selected from overlaying the maps of slope, aspect and height using geographic information system (GIS). Within each unit, vegetation sampling was performed with randomized-systematic method along three transects of 100 m length. Ten plots (1m2) were established along each transect at 10 meter intervals. Soil samples were taken from 0-30 centimeter in starting, mean and ending points of each transect. Soil factors such as N, P, organic matter, pH, EC and texture were measured. CANOCO software and redundancy analysis (RDA) were used to examine the relationship between species and environmental factors. The first axis of RDA showed a significant correlation with slope, aspect, sand, silt, P, pH and litter, while the second axis had just a significant correlation with EC.
Masoud Borhani; Hossein Arzani; Zahra Jaberolansar; Mojgan Azimi; Mahdi Farahpor
Volume 17, Issue 1 , September 2010, , Pages 1-20
Abstract
Range condition is known as an important indicator for assessment in range management. Many techniques have been exploited for determining this indicator, from which four-factor method has been used in this study. Some communities at stepic regions of Isfahan province were selected. In each selected ...
Read More
Range condition is known as an important indicator for assessment in range management. Many techniques have been exploited for determining this indicator, from which four-factor method has been used in this study. Some communities at stepic regions of Isfahan province were selected. In each selected community, an area was chosen as key area, and a total of eight sites were selected in the key areas. Soil erosion, canopy cover, plant composition, and plant vigor were monitored for each site. The results revealed a significant difference between the sites in terms of the above mentioned parameters, as well as their rainfall (p<0.01). Moreover, there was a significant correlation between annual precipitation and range condition score. The correlation showed different patterns within years in each site, where the difference between years was significant in terms of plant vigor and canopy cover, but non-significant in terms of soil erosion and plant composition. There was also a positive correlation between the trend of individual parameters and the overall condition score. Cluster analysis grouped Aluyjeh, Northern Shahreza, and Charmshahr sites in one branch, Mooteh, Shoorabad, and Golpayegan in another, and finally Komeshcheh and Southern Shahreza in a third branch. The lowest rank for canopy cover, canopy production and soil erosion belonged to Komeshcheh and Southern Shahreza sites. Aluyjeh, Northern Shahreza, and Charmshahr sites were in better condition than the previous group, yet in poor conditions, and the rest of the sites showed the best conditions among study sites. Generally speaking, Isfahan's stepic rangelands are ranked as poor to very poor, while their condition showed a constant trend.