Mehri Dinarvand; Mohammad Fayaz; Hashem Keneshlo; Kourosh Behnamfar; Sajad Alimahmodi sarab; farhad khaksarian
Volume 29, Issue 1 , February 2022, , Pages 99-111
Abstract
Measuring the diversity and identifying plant vegetation traits and functional groups and classifying them, in addition to helping to accurately identify the vegetative capacity of the area, helps us to understand the vegetation response of the area to disturbances and presence. Potentially resistant ...
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Measuring the diversity and identifying plant vegetation traits and functional groups and classifying them, in addition to helping to accurately identify the vegetative capacity of the area, helps us to understand the vegetation response of the area to disturbances and presence. Potentially resistant species with similar or invasive traits help. The purpose of this study was to investigate and evaluate the vegetative status of the region, the trend of changes and evaluation of the second sequence of dust centers in Khuzestan after planting seedlings in different ways. Functional groups (PFTs) were used. To evaluate the changes in the vegetation of the area by field survey, 15 transects of 100 meters with distances of 50 meters were systematically randomly selected (the first transect was randomly selected and the rest with a defined distance of 50 meters). Due to the uniformity of plant species composition and the absence of environmental effects, a total of 180 fixed plots with dimensions of 1 square meter (location recording with GPS device) were installed. The results of a recent study in three areas of the dust center in the southeast of Ahvaz showed that in selected areas, various irrigation methods along with rainfall will cause significant changes in the percentage of cover (frequency) and the number of species from 2017 to 2020. Functional groups in the Tovayel region with surface irrigation (Faro) In 2020, nine groups were identified, in Bagan region with tanker irrigation and hole digging with seven excavators, and in Hanitieh region with tanker irrigation and hole digging seven functional groups. The results of T-test analysis also showed that there is a significant difference between the average of the two values of all indicators, including the diversity of Shannon and Simpson in March 2017 and March 2020 for all three regions so diversity indicators raised since number of species and cover increased.
Kourosh Behnamfar; Farhang Ghasriani; Mohammad Fayaz; Rajabali Mohamadi
Volume 28, Issue 2 , June 2021, , Pages 222-237
Abstract
Cymbopogon olivieri is a perennial grass in tropical regions. This species has very high compatibility in the rangelands of Khuzestan province by benefiting from type C4 photosynthesis. This species is specific to warm areas. The variation in the habitats of this species causes differences in phenotypes ...
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Cymbopogon olivieri is a perennial grass in tropical regions. This species has very high compatibility in the rangelands of Khuzestan province by benefiting from type C4 photosynthesis. This species is specific to warm areas. The variation in the habitats of this species causes differences in phenotypes and forage yield of its populations. In order to evaluate the populations of Cymbopogon olivieri species, at first, the addresses of herbarium were studied, and its habitats in Khuzestan province were identified by field surveys. Then, at the appropriate time, the seeds of seven identified populations were harvested from different habitats of the province and were planted in the Baghmalek research station and evaluated for three years (2011-2014) after establishment. To measure the traits from each population, at the stage of spike emergence, aerial parts of plants were harvested in three plots of 3 m2 from a height of 5 cm above the ground. After counting the number of tillers and plant height, they were dried and weighed in an oven at 70 ° C for 48 hours to determine dry forage yield, aerial parts. There was a significant difference between the studied populations for dry forage yield, plant height, and the number of tillers. The highest forage yield of Cymbopogan olivieri in the third year after the establishment of populations collected from Dezful-Dez Dam, Masjed Soleiman-Bardemar and Ahvaz-Masjed Soleiman route with a production of about 110 g dry m-2 and then Shushtar -Abgah, and Dezful- Shahion with a production of about 100 g dry m-2 respectively. In terms of plant height, populations related to Dezful-Dez Dam, Shushtar-Abgah, and Dezful-Sardasht-Gavmir with a longitudinal growth of more than 50 cm were statistically superior. In terms of mean tiller number per plant, the Dezful-Dez dam population with 125 tillers had the highest and the Ahwaz-Masjed Soleiman route population with an average of 69 tillers had the lowest tiller number per plant.
Kourosh Behnamfar; Aziz Orsham; Mohamad Hasan Salehe Shoshtari; Mehrzad Tavousi; Abdolreza danaie; jamaladdin Adel
Volume 26, Issue 1 , June 2019, , Pages 49-61
Abstract
The occurrence of below-zero temperatures in recent winters in Khuzestan province has caused the freezing of Prosopis juliflora trees. The aim of this study was to determine the sensitivity of this species to freezing under zero temperatures. In this study, a split split plot was used in a completely ...
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The occurrence of below-zero temperatures in recent winters in Khuzestan province has caused the freezing of Prosopis juliflora trees. The aim of this study was to determine the sensitivity of this species to freezing under zero temperatures. In this study, a split split plot was used in a completely randomized design with six replications. In order to apply the treatments, the branches of elderly trees and two-year old seedlings were considered as main treatment; below-zero temperatures (-1-, -3, -5 and 7 ° C) as the first sub treatment; and different times (1, 2, 3 and 4 hours) as the second sub-treatment. The amount of electrolyte leakage from the membrane of leaf and stem cells was measured and, based on this, LT50 was calculated. The chlorophyll (II) fluorescence and photosynthesis efficiency of the leaves were measured as indicators for determining the damage to frost. The results showed that there was no significant difference for all traits between branches of the old trees and two-year-old seedlings. The percentage of electrolyte leakage from leaf and stem increased significantly with decreasing temperature. The LT50 occurred at -5 ° C after three hours. At -7 ° C, after the first hour, LT50 occurred in the leaves and after the third hour in the stems. After freezing stress, the Fv/Fm decreased significantly. After two hours at -1°C, Fv/Fm did not change significantly but in three hours Fv/Fm decreased from 0.64 (in control) to about 0.48. It reached to 0.15 after applying four hours at -7°C.
Kourosh Behnamfar; Seyed Ataollah Siadat; Mohammad Hasan Salehe Shoshtari
Volume 21, Issue 1 , June 2014, , Pages 41-50
Abstract
In order to study and design a mixed plantation of rangeland and forest species (silvopastoral system), four rangeland species and three shrub and tree species were planted with different row spacings on the sand dunes of Karkheh river, in Khuzestan province. The biological stabilization of sand ...
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In order to study and design a mixed plantation of rangeland and forest species (silvopastoral system), four rangeland species and three shrub and tree species were planted with different row spacings on the sand dunes of Karkheh river, in Khuzestan province. The biological stabilization of sand dunes and production of forage were the aims of this study. The selection of species was done according to their ability to improve the production of forage, firewood, and industrial wood as well as species diversity. The study was performed using split plot in a completely randomized design with three replications for four years. The main treatment included tree and shrub species (Eucalyptu camaldulensis 9616, Acacia victoriae ,Prosopis juliflora). Row spacings of 4*4, 5*5, 6*6, and rangeland species (Panicum antidotale,Cenchrus ciliaris ,Cymbopogon olivieri , Pennisetum divisum) were considered as the first and second sub-treatments, respectively.Vitality percentage of all species, forage yield of rangeland species, and height growth of shrub and tree species were measured. Data were analyzed by SAS software and mean comparisons were performed by Duncan's Multiple Range Test. According to the results, C. olivieri (90%) and C. ciliaris (60%) showed the highest and lowest vitality of rangeland species. Among tree and shrub species, E. camaldulensis (80%), P. juliflora (65%), and A. victoriae (50%), showed the highest vitality, respectively.In four-meter row spacings of E. camaldulensis, forage yield of all range species decreased. In terms of height growth, E. camaldulensis, with a height of around 3.5 m, was better as compared to the other two species. The highest average dry matter yield was recorded for P. divisum (1437 Kg ha-1), P. antidotale (1035 Kg ha-1), C. olivieri (380 Kg ha-1), and C. ciliaris (235 Kg ha-1), respectively. Therefore, the determination of appropriate row spacing for trees causes to increase of species diversity as well as continued and increasing forage production and utilization.