Journal of Rangeland

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This study aimed to evaluate the effects of various grazing intensity levels on rangeland indices. Various vegetation indices and soil parameters were compared in low, moderate and high grazing pressure in Tolkoloo rangelands-Ardabil province. Three transects were established in each grazing intensity area and 10 plots of 1 m² were placed in each transect and their species composition, density, canopy cover, litter, bare soil, stone and gravel percentages were recorded. Soil samples were collected from zero to thirty cm of soil depth in first, fifth and tenth plots of each transect. The soil parameters such as pH, electrical conductivity, sodium, magnesium, calcium, potassium, lime, phosphorus, organic carbon, organic matter and the percentages of sand, silt, and clay were measured in all soil samples. One-way analysis of variance and Duncan test were used for analyzing data. The results showed that plants canopy covers were decreased and bare soil, stone, and gravel percentage were increased significantly in severe grazed areas (P < 0/01). Trigonella monspeliaca L. and Astragalus rostratus C.A.Mey. were dominant palatable species in low grazing areas and their canopy cover were 30.94 and 6.44, and their densities were 104.23 and 12.10 stand per one m² respectively. The palatable species canopy covers were decreased by increasing grazing pressure while canopy covers of low palatable species (class II and III) increased. Although high grazing pressure caused a decline in soil organic carbon, clay, potassium, magnesium contents and soil pH, electrical conductivity, phosphorus, calcium, lime, and sand were increased significantly (P < 0/01). Overall, increasing grazing intensity reduced total canopy cover and soil nutrients, modified species composition, and caused instability of rangeland ecosystem. According to the results, grazing gradient framework can be used for range assessment in Moghan plain.
 

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Insight into the rangeland ecosystems, its components and their relationships, soil and vegetation for instance, is among the keys of proper range management. On the other hand, the use of machine learning methods to discover the relationship between these factors can help in Cost reduction of Soil sampling and testing. In this study therefore, the effect of some soil characteristics on distribution of Artemisia sieberi is tested in Nodoushan rangelands, Yazd province. Coverage information was measured in 320 plots put alongside of 40 transects. The soil profiles were dug at the beginning and end of each transect to take soil samples from two depths of 0 to 10 and 10 to 30 cm. samples were taken to the lab to be analyzed. Coverage percent of Artemisia sieberi was determined by using a machine learning method. Soil parameters and six algorithms were used for the task. Then, with weighting the factors, their effect on the prediction of the coverage was investigated. The results of the model showed that “Gaussian process model” with (RMSE= 1.385) and (R= 0.998) in the training dataset and (RMSE = 0.960) and (R = 0.9999) in the test dataset has a higher accuracy on the prediction of  the coverage percentage than other models. Weighting results also showed, that among the soil parameters, sodium at depths of 0 to 10 and 10 to 30 cm, has the most effect on vegetation estimation. The results generally showed that high soil parameters and machine learning methods are good way of  coverage prediction in the area.

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Background and objectives: Halophytes are plants resistant to salinity and have the potential to produce edible oil in their seeds. The focus on cultivating halophytes and salt-tolerant plants for edible oil production is increasing, primarily due to the critical salt problem in arid and semi-arid regions of the world, such as Iran. Large areas of salty lands, particularly in arid and semi-arid countries like Iran, make these plants especially valuable in saline lands. This study aims to investigate the quality and quantity of edible oil from three halophyte species- Halocnemum strobilaceum, Nitraria schoberi, and Suaeda aegyptiaca - in the rangelands around Hoze Soltan, Qom Province, to suggest their cultivation in saline lands.
Methodology: This study was conducted in the saline habitats of Qom Province around Hoze Soltan. After preparing vegetation maps and conducting field investigations, different plant types were selected at each site, and sampling was performed in each reference region. During the seeding phenological stage, three seed samples were prepared for each species in each region based on a completely randomized design. The first replication was chosen randomly near the salinity center, with the second and third replications selected at 200-meter intervals from the previous replication. Ten plants of each species were randomly selected in each replication. For each species in every region, three seed samples (corresponding to three replications in the seeding stage) were sent to the oil analysis laboratory. The oil percentage and fatty acid composition were determined using Soxhlet extraction and gas chromatography, respectively. Soil parameters were measured after sampling. All statistical analyses and correlations were performed using SPSS software.
Results: The findings showed that Suaeda aegyptiaca had a higher seed oil percentage than Halocnemum strobilaceum and Nitraria schoberi. Seven types of fatty acids were identified in the oil obtained from the seeds of the three studied species. The dominant saturated and unsaturated fatty acids were palmitic acid and linoleic acid, respectively. The results of RDA analysis indicated that the oil and linoleic acid content in S. aegyptiaca were higher than in other species. The highest amounts of sapienic, behenic, stearic, and arachidic acids were observed in N. schoberi. Palmitic acid was most abundant in H. strobilaceum.
Conclusion: Among the three studied species, Suaeda aegyptiaca is recommended for restoring saline regions of Hoze Soltan in Qom Province due to its desirable oil production and higher amounts of oil and linoleic acid. Cultivating and utilizing S. aegyptiaca in saline lands where agricultural plants cannot be cultivated not only conserves the soil and prevents desertification but also provides a viable option for entrepreneurship, production, and obtaining plant oils from halophytes. Further research and identification of oily halophyte species are needed.