Hamed Joneidi; Neda Ragideh; Parviz Karami
Volume 31, Issue 4 , January 2025, , Pages 382-394
Abstract
Background and objectivesAllelopathy refers to the direct and indirect harmful effects of one plant on another. These effects occur through the production of allelochemical compounds and their release into the environment, causing stimulation or inhibition. Considering the importance of the ecological ...
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Background and objectivesAllelopathy refers to the direct and indirect harmful effects of one plant on another. These effects occur through the production of allelochemical compounds and their release into the environment, causing stimulation or inhibition. Considering the importance of the ecological relationships of the two species Daphne mucronata and Amygdalus lycioides as one of the most important and suitable plants for implementing rangeland improvement projects in the region, it is essential to examine their allelopathic relationships in order to achieve the results of improvement programs.MethodologyIn order to investigate the separation factors of D.mucronata and A.lycioides habitats, the effect of the allelopathic D. mucronata was studied on the early seedlings of Amygdalus Lycioides seeds. An experiment was conducted in an entirely randomized design with 20 iterations to investigate the allelopathic Daphne effects on germination (percentage and velocity, plumule growth, early growth indices (seed vigor, percentage deterrence, average germination time, mean germination time) and A. lycioides seeds. Test treatments were accomplished with the ratio of 0 (control), 20, 40, 60 and 80 percentages for both root and leaf extracts in experiment in a plate and germinator. Data analysis was performed using one-way ANOVA. Duncan test was used for grouping these treatments. All statistical analyses were performed in SPSS software.Result According to the results, the allelopathic effect was observed in D. mucronata leaf extract in concentrations of 60 and 80% and D. mucronata root extract in all concentrations. D. mucronata leaf extract in concentrations of 60 and 80% decreased germination (by 6.5% and 13%, respectively), root length (by 20.1% and 26.2%, respectively) and inhibition percentage (respectively). 6.8 and 13.6 percent). The greatest effect of D. mucronata root extract on A.lycioides seeds was observed at a concentration of 80%, which decreased the germination percentage (69%), root length (93.01), inhibition percentage (73%) and average germination time (9.2%). and germination speed (12.42%).The root extract showed more allelopathic effect than the leaf. Also, in both root and leaf extracts, the allelopathic effect increased with increasing concentration. Finally, these investigations showed that the effect of allelopathy is one of the factors that played a significant role in the separation of daphne and almond habitats in a region. This finding indicates that when implementing rangeland improvement projects, especially biological operations in similar areas using these two species, ecological considerations should be taken into account in terms of the harmful effects of these two species on each other to increase the likelihood of success of such projects.
Leila Zandi; Reza Erfanzadeh; Hamed Joneidi Jafari
Volume 29, Issue 1 , February 2022, , Pages 24-35
Abstract
The aim of this study was to investigate the effect of conversion of rangeland into agricultural and horticultural land uses on important soil properties including aggregate stability in Salavatabad watershed in Eastern Sanandaj. For this purpose, simultaneously with the predominant growth of plants, ...
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The aim of this study was to investigate the effect of conversion of rangeland into agricultural and horticultural land uses on important soil properties including aggregate stability in Salavatabad watershed in Eastern Sanandaj. For this purpose, simultaneously with the predominant growth of plants, four land uses including 1) rangeland 2) orchard 3) chickpea field 4) wheat field were selected as the study area and 42 soil samples were random-systematically collected. Then soil physico-chemical properties including aggregate stability, total nitrogen, total carbon and particulate organic carbon of each sample were measured in the laboratory. One-way ANOVA of the data showed that due to the conversion of rangeland into three uses of orchard, chickpea and wheat fields, aggregate stability, particulate organic carbon at the level of 5%, total organic carbon and total nitrogen in all three uses at the level 1% decreased significantly. As the aggregate stability in orchard, chickpeas and wheat 35.51, 25.94 and 19.56% respectively, particulate organic carbon in orchard, chickpeas and wheat 62.5%, 79.16 and 75%, respectively, total organic carbon in orchard, chickpea and wheat use decreased by 23.63%, 50% and 49.09%, respectively, and total nitrogen decreased by 31.25% in orchard, 62.5% in chickpea use and 75% in wheat use. According to the results of this study, the conversion of rangelands to any of the agricultural and horticultural uses is unacceptable, but in case of forced conversion, the use of the orchard is recommended because the orchard has less negative effects on soil quality factors than wheat and chickpeas. It is also emphasized in converting rangeland use to cropland, as much as possible to maintain the balance between the input and output of the plant residual into the soil bed, it should be prevented the exit or fire of remaining straw, or grazing livestock after harvest.
Nahid Azizi; Hamed Joneidi; Khaled Osati
Volume 26, Issue 3 , September 2019, , Pages 717-730
Abstract
This research monitored changes in canopy cover percentage of typical species during a 10-year period in the Ghosheh rangelands to find out the relationship between two important climate variables (precipitation and temperature) and canopy cover changes. Therefore, the canopy cover ...
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This research monitored changes in canopy cover percentage of typical species during a 10-year period in the Ghosheh rangelands to find out the relationship between two important climate variables (precipitation and temperature) and canopy cover changes. Therefore, the canopy cover percentages of six typical species (separately) and annual species (overall) were measured during 10 years at the end of growing season in thirty 2-m2 plots, distributed along two 250–m transect lines. The results demonstrated that the maximum canopy cover percentage for water year 2006-2007 (wet-year) and the minimum value for water year 2012-2013 (drought) were 15% and 5.5%, respectively. The canopy cover percentage modeling was performed based on linear regression method using precipitation and temperature variables. The precipitation of April explained 65% of changes in canopy cover percentage of A. sieberiat 95% confidence level (RRMSE = 0.26 & MAE=0.49). The best simple linear regression model for estimating canopy cover percentage of S. barbata and Z. eurypterum was introduced by total precipitation of March-June and precipitation of March, representing 77% (at 99% confidence level) and 67% (at 95% confidence level) of changes in canopy cover, respectively. Considering the dominant role of A. sieberi, S. barbata and Z. eurypterum in vegetation composition of study areas, it can be concluded that most changes in canopy cover of the studied rangeland are predictable by variabilityofprecipitation during growing seasons.