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.
Zahra Jaberalansar; Masoud Borhani; Babak Bahreininejad; Hamidreza Mirdavodi
Volume 28, Issue 3 , October 2021, , Pages 551-563
Abstract
Understanding the ecological characteristics of plant species and how they respond to environmental factors provides the information needed to manage vegetation and restore rangeland ecosystems. The aim of this study was to determine the environmental factors affecting the habitat of Krascheninnikovia ...
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Understanding the ecological characteristics of plant species and how they respond to environmental factors provides the information needed to manage vegetation and restore rangeland ecosystems. The aim of this study was to determine the environmental factors affecting the habitat of Krascheninnikovia ceratoides (L.) species and its response to changes in ecological factors in the rangelands of Isfahan province. Accordingly, canopy cover and density of K.ceratoides and the associated species were measured in 19 ecological sites using random systematic sampling method. In each site, climate, physiography and soil factors were identified. Canonical Correspondence Analysis (CCA) and Generalized Additive Models (GAM) using CANOC4.5 software were used to investigate the vegetation relationship with environmental factors. The results showed that the response pattern of K. ceratoides along the gradient of absorbable potassium follows the incremental model. Conversely, the response of this species along the gradient of sand percentage, average annual temperature and rock and gravel percentage has followed a decreasing model and with increasing these factors, the percentage of canopy cover has decreased. The response pattern of K. ceratoides along the changes of the amount of absorbed phosphorus, the percentage of gypsum and the altitude of the sea, follows the bell model (Unimodal), and its optimal growth limit for these factors is 10 mg kg-1, 6.4% and and 2250 meters. The study of K. ceratoides species response along the gradient of topographic, soil and climate factors provided valuable information to determine the ecological needs of this species that can be considered in vegetation management and rangeland improvement operations in similar areas.