https://aridbiom.yazd.ac.ir/ Journal of Arid Biome en daily 1 Fri, 21 Mar 2025 00:00:00 +0330 Fri, 21 Mar 2025 00:00:00 +0330 https://aridbiom.yazd.ac.ir/article_3940.html The aim of this study is to estimate the water requirement of green spaces in the University of Sistan and Baluchestan using the landscape coefficient and classifying water requirement for each plant species based on (WUCOLS) method. The university's green spaces (area 20.46 hectares) was divided into three zones according to three characteristics of the landscape coefficient, including plant factor, planting density, and existing microclimate. Zone A (coniferous trees with high density and green cover on the ground), zone B (broadleaf trees with medium and low density and green cover on the ground), and zone C (grasslands with low density, scattered trees and shrubs and soil cover on the ground). Climatic data from the Zahedan meteorological station over a 30-year period (1993-2023) were used to calculate reference evapotranspiration and effective rainfall. Findings show that the annual water requirement estimation to irrigate the entire green space is 872664.76 cubic meters with an efficiency of 35%. Maximum annual water resource consumption among the existing zones in order is, zone B (480141.53 cubic meters), zone A (385241 cubic meters) and zone C (7282.23 cubic meters). Planning to remove the ground level green cover in Zone A, due to high density of pine trees, and also replacing ornamental grass species in Zone B with xeriscape plants and artificial mulches can be short-term solutions to reduce water consumption in the university's green space. Also, developing sprinkler and drip irrigation systems and maximizing the use of gray water resources instead of drinking water in all three zones is proposed as a long-term solution. https://aridbiom.yazd.ac.ir/article_3941.html The amount of sediment and suspended matter in flowing water is a significant concern in the design of hydraulic structures, such as channels, gates, and dam turbines. This issue is very important for several reasons, including maintaining soil quality in agricultural lands, addressing environmental concerns, and managing water resources for drinking and industry. Meanwhile, remote sensing technology has become an efficient and popular tool for natural resource management and assessment, offering time and cost savings as well as more accurate results than traditional methods. This study aimed to estimate suspended sediments in the Dez Dam basin, from upstream to downstream, using Sentinel-2 time-series satellite data collected between 2015 and 2021. For this purpose, the Suspended Sediment Concentration (SSC) index was extracted, and the results were calibrated using data from hydrometric stations. The results showed that satellite reflectance and suspended sediment concentration (SSC) depend on the wavelengths of the imaging bands. In a study of 12 bands of Sentinel images, bands 4 and 5 exhibited the highest correlation with sediment concentration. According to the results, the highest accuracy was observed in June 2020, with a coefficient of determination of 0.89, while the lowest accuracy was recorded in June 2021, with a coefficient of determination of 0.69. In 2015, the coefficient of determination for Farvardin was 0.78, while for Khordad, it was 0.82. In 2017, the accuracy for Farvardin and Khordad was 0.88 and 0.74, respectively. https://aridbiom.yazd.ac.ir/article_3942.html Today, as the adverse effects of climate change become increasingly evident worldwide, scientists are concentrating on artificial desert forests as a novel source and potential means of carbon sequestration. This study aimed to investigate the Saqaleh-Sarayan region of South Khorasan province. In the first step, the restoration and development of artificial forests in the study area were examined using remote sensing images from Landsat 5 and 8 satellites, which have a 30-meter resolution and cover the years 1369 to 1402. This was conducted with a modified vegetation cover index adjusted for soil MSAVI. Next, to evaluate in the field, vegetation types and representative areas were identified, and five transects of 300 meters were established both randomly and systematically. By measuring five plots of 4 square meters along each transect, the density was calculated. Since black alder was the only dominant species in the study area, three stands of each type were cut at different heights to determine biomass weight accurately. The aerial and underground components were then completely removed and weighed. To evaluate soil carbon content using the Walkey and Block method, five topsoil samples were taken from a depth of 5-15 cm for each type. Subsequently, the plant carbon content was determined via combustion. The results showed spatial and temporal changes in the MSAVI index, which rose from 057 in 1980 to 22 in 1983. This increase was noted as moving from the north and northwest towards the east and southeast of the region. The average number of thuja shrub stands across various types was 308 stands per hectare. The total carbon sequestration in the man-made forests of the Sah Qala region was estimated at 1063838.5 tons, which equates to 106 kg and 11346 tons per hectare across the studied plant section, while in the soil section, it was 1349.7 kg and 1052492.5 tons, respectively. Overall, the carbon sequestration capacity in arid and desert areas can be attributed to the expanse of these lands, as soil organic carbon levels in these regions are typically low. Nevertheless, man-made forests in desert areas significantly contribute to the sequestration of organic carbon. https://aridbiom.yazd.ac.ir/article_3988.html German chamomile (Matricaria chamomilla L.) is a medicinal plant with a wide range of applications, the therapeutic properties of which largely depend on the quantity and quality of its essential oil. In arid regions, deficit irrigation is a critical management strategy for optimizing water use and enhancing productivity, as it can increase the concentration of secondary metabolites in medicinal plants. Furthermore, the foliar application of certain compounds may have an eliciting effect, boosting the production of medicinal metabolites. This study investigated the effects of deficit irrigation and elicitor compounds on the quantitative and qualitative yield of German chamomile. A split-plot experiment, arranged in a randomized complete block design with three replications, was conducted in 2021 at the Agricultural Sciences and Natural Resources University of Khuzestan. The main factor was deficit irrigation at three levels (irrigation after 60 mm (control), 80 mm, and 100 mm of evaporation from a class A evaporation pan). The sub-factor was the foliar application of four types of elicitors: control (distilled water), sorbitol, mannitol, and ethanol. The results indicated that with increasing deficit irrigation intensity, fresh and dry biomass yield decreased; however, essential oil percentage and yield, dry flower weight, and chamazulene content increased significantly. Foliar application of elicitors, particularly sorbitol, mitigated the negative effects of drought stress and positively influenced the essential oil's quantitative and qualitative yield. The highest essential oil content (1.57%) and chamazulene percentage (1.86%) were observed under the combined treatment of severe deficit irrigation (100 mm evaporation) and sorbitol application. In conclusion, the combined application of mild drought stress and sorbitol foliar spraying can be recommended as an effective management strategy to enhance the economic return of chamomile essential oil production. https://aridbiom.yazd.ac.ir/article_3987.html Rangelands serve as crucial reservoirs of biodiversity and play a vital role in the balance of dry and semi-arid ecosystems. This research aimed to analyze the trends in vegetation cover and species diversity in the semi-arid warm rangelands of the Bardemar region in Khuzestan province, and to investigate their relationship with rainfall fluctuations over a seven-year period (2018-2024). Field sampling was conducted using a random-systematic method, employing four fixed transects and 40 one-square-meter plots in each sampling period. Throughout this duration, parameters including canopy cover percentage, density, and above-ground plant biomass were measured, and species diversity indices, namely the Simpson and Shannon-Wiener indices, were calculated. The studied area's flora consists of 113 species from 31 plant families, with Asteraceae (28 species), Apiaceae (8 species), and Lamiaceae (3 species) being the richest families. Annual plants (therophytes), represented by 72 species (64%), constitute the dominant life form, followed by hemicryptophytes (19%) and chamaephytes (8%). The obtained results revealed significant fluctuations in vegetation parameters. Canopy cover percentage increased from 18.80% in 2018 to 37.10% in 2023, while forage production varied between 140.59 and 400.49 kg of dry matter per hectare. Data indicated that the peak in both the quantity and quality of vegetation occurred during the high-rainfall years of 2019 and 2023, which received 312.75 mm and 320.65 mm of precipitation, respectively. Consistent with these observations, the Shannon index value increased from 0.76 in 2018 to 1.05 in 2021, and the Simpson index also recorded higher values (0.57 to 0.60) during wetter years, indicating a positive influence of rainfall on species richness and evenness. In conclusion, the findings of this study clearly demonstrate the strong dependence of the structure and function of vegetation in semi-arid warm rangelands on rainfall fluctuations. It emphasizes that annual precipitation acts as the primary environmental factor controlling the dynamics and diversity of these sensitive ecosystems. https://aridbiom.yazd.ac.ir/article_3994.html Vegetation is a fundamental component of natural ecosystems and plays a crucial role in soil conservation, carbon sequestration, and climate change. It serves as an important indicator for assessing ecosystem functionality and health. Proper vegetation management requires an understanding of its current status and long-term trends. Given the lack of historical vegetation data, remote sensing technology plays a critical role in assessing long-term vegetation dynamics. This study investigates vegetation cover changes in Ivan County, Ilam Province, over a 24-year period (2000–2024) using multi-temporal Landsat satellite imagery across five distinct time intervals (2000, 2005, 2010, 2015, 2020, and 2024). In this regard, different vegetation cover classes (bare, poor, moderate, good, and excellent) were first extracted and analyzed based on NDVI index data. Furthermore, vegetation cover changes (increased, unchanged, and decreased) were assessed for two 10-year periods (2000-2010 and 2015-2024) using image differencing and change thresholding methods. To assess the significance of observed change trends, the Mann-Kendall test was employed. The results revealed that the poor vegetation class represented the most extensive vegetation cover type in the study area, exhibiting a declining trend throughout the study period. Specifically, its coverage decreased from 88.18% in 2000 to 39.86% in 2020. Conversely, areas with moderate and good vegetation cover demonstrated increasing trends, rising from 10.74% and 1% in 2000 to 41.09% and 11.29% in 2024, respectively. The Mann-Kendall test results indicated that areas with poor vegetation cover exhibited a statistically significant decreasing trend, while those with moderate and good cover showed statistically significant increasing trends. However, areas with excellent vegetation cover and bare lands displayed no significant trends. According to the image differencing results, the majority of the study area (94.55%) remained unchanged during the 2000-2024 study period. The findings of this study demonstrate the high efficacy of remote sensing tools, particularly vegetation indices, for long-term vegetation monitoring. Furthermore, the results suggest that since the observed increase in moderate, good, and excellent vegetation classes primarily resulted from expanded irrigated lands and conversion of croplands to orchards; rather than improvement of forest or rangeland conditions conservation management programs should be implemented to enhance rangeland quality and prevent conversion of natural resources to agricultural uses, and promote natural revegetation to replace areas with poor vegetation cover. https://aridbiom.yazd.ac.ir/article_3996.html This study aims to develop a system dynamics model to simulate the groundwater conditions of the Isin plain aquifer and to assess groundwater supply and demand in the agricultural and domestic sectors under a business-as-usual scenario, projected through the horizon year 2031. The proposed model was developed by considering three subsystems: groundwater resources, water demand, and population. It simulates and forecasts the volume of the groundwater reservoir, the demand and deficits in agricultural and domestic water consumption, as well as the population. The dynamic model of the proposed system was developed using Vensim software and was calibrated and verified for the period of 2010-2020 for the Isin Plain-Bandar Abbas aquifer. The relevant variables were then simulated up to the horizon of 2031. The results showed that the model has a high level of accuracy in simulating the status of the groundwater resources system. Considering that agricultural water demand is decreasing at a negative growth rate, it is expected to decline to 6.7 MCM by 2031. As a result, the agricultural water deficit has also decreased. The population of Isin Plain will have increased by 7,722 people by 2031, and the domestic water demand will rise from 4 MCM to 12.1 MCM. The Isin Plain has experienced a drinking-water deficit of 3.9 MCM since 2022, and this deficit is projected to reach 10.7 MCM by 2031. Considering that the agricultural sector, as the main consumer of groundwater, has shown a downward trend, the volume of the Isin groundwater resource increased from 128 MCM in 2020 to 226.5 MCM in 2031. The supply and demand of groundwater in this plain should be based on sustainable development, as the future of agriculture in the Isin plain is facing a serious crisis with significant economic and social consequences for the users. In addition, the transfer of treated wastewater from the city of Bandar Abbas, the expansion of artificial recharge facilities, and the dredging of previously constructed infrastructure will contribute to improving the condition of the aquifer. https://aridbiom.yazd.ac.ir/article_4033.html Winter heat waves are among the rare but influential climatic phenomena in the arid regions of Iran, with significant environmental and agricultural consequences. In this study, the frequency, trend, and statistical characteristics of heat waves were analyzed using daily maximum temperature data over a 15-year period (2003–2017) from seven synoptic stations in Yazd Province, including Yazd, Meybod, Bafq, Aqda, Marvast, Gariz, and Robat-e Posht-e Badam. The results revealed that the highest number of heat-wave events was recorded at Bafq station in 2017 with 17 events, while Yazd station experienced 14 events in both 2005 and 2017. The longest heat-wave episode occurred at Yazd station during autumn 2007 and persisted for 28 days, whereas the longest event at Marvast station lasted 23 days in 2016. Seasonal analysis indicated that in Meybod, Bafq, Aqda, and Robat-e Posht-e Badam stations, the highest occurrence of heat waves was observed in autumn, accounting for more than 51% of all events. In contrast, Yazd, Gariz, and Marvast stations experienced the highest frequency of heat waves during winter, representing more than 52% of total events. The non-parametric Mann–Kendall test and Sen’s slope estimator indicated increasing trends at all stations except Robat-e Posht-e Badam. The strongest positive trend was detected at Bafq station with a Sen’s slope of Q = 0.182 and a Mann–Kendall statistic of Z = 1.01. Synoptic analysis of the most extensive and persistent heat wave (a 10-day event in December 2005) demonstrated that the establishment of the Azores High ridge at the 500-hPa level and warm air advection from the Arabian Peninsula at the 850-hPa level played a dominant role in the development of this event. These findings suggest an increasing likelihood of the persistence and intensity of winter heat waves in the arid climate of Yazd Province under the influence of climate change. https://aridbiom.yazd.ac.ir/article_4034.html Drought is one of the most significant climatic phenomena, with substantial impacts on natural resources, agriculture, and the economies of human societies. Among the various types of drought, meteorological drought is considered a primary indicator for the analysis of both long-term and short-term droughts due to its direct relationship with atmospheric conditions, particularly variations in temperature and precipitation. This phenomenon can significantly influence vegetation and water resources by altering precipitation patterns and land surface temperature. The Semnan Shurab Basin, located in an arid and semi-arid region of Iran, is highly sensitive to climatic variability and changes in land surface temperature. In this study, the Vegetation Health Index (VHI) was used to examine the relationship between drought conditions and vegetation dynamics. First, VHI values were calculated for four 16-day periods corresponding to the months of April, May, and June—when natural vegetation in Iran typically reaches its peak—over the period from 2001 to 2022. Subsequently, the Standardized Precipitation Evapotranspiration Index (SPEI) was computed at a 12-month time scale for ten meteorological stations located within and around the study area. The SPEI values were spatially interpolated using the inverse distance weighting (IDW) method. In the final step, the correlation coefficients and trend slopes between the 12-month SPEI and VHI were calculated and analyzed. The results indicate a strong correlation between the standardized precipitation–evapotranspiration index and vegetation condition, particularly in April and May. Furthermore, the assessment of vegetation sensitivity to climatic fluctuations and drought in the Semnan Shurab Basin using VHI reveals a spatially diverse response of vegetation to climate variability. https://aridbiom.yazd.ac.ir/article_4035.html Drought, as one of the most complex and multidimensional climatic phenomena, is inherently associated with high uncertainty and nonlinear dependencies among climatic variables. In this study, a hybrid framework integrating phase space reconstruction (PSR), Vine Copula, and quantile regression was developed to improve the accuracy and interpretability of drought prediction in the hyper-arid climate of Bandar Abbas over the period 1960–2022. The results demonstrate that phase space reconstruction, by unveiling the hidden dynamical structure of the SPEI time series, significantly enhances model performance, such that the coefficient of determination (R^2) in the testing phase increases from approximately 0.10 to more than 0.80. The Vine Copula approach effectively captures the nonlinear and asymmetric dependencies among climatic variables and, when combined with PSR, provides a coherent framework for representing the dynamic behavior of the drought system. Quantile-based models, including QRF, QXGBoost, and QVineCopula, not only improve predictive accuracy but also enable data-driven quantification of uncertainty, resulting in superior coverage of prediction intervals (PICP = 0.91). Variable importance analysis highlights the dominant role of lagged SPEI components—particularly SPEI9 and SPEI8—along with maximum temperature and wind speed, in governing regional drought dynamics.Overall, the hybrid PSR–QVineCopula model achieves an optimal balance between accuracy, robustness, and interpretability, and offers a novel framework for both deterministic and probabilistic drought prediction in hyper-arid regions. https://aridbiom.yazd.ac.ir/article_4039.html The desert regions of Semnan Province, characterized by arid and fragile climatic conditions, are increasingly threatened by interconnected challenges such as desertification, depletion of water resources, and intensified soil erosion. This study aims to provide a strategic analysis of the role of indigenous knowledge in combating desertification and promoting the sustainable management of natural resources by evaluating the capacities of local communities and their traditional practices. To achieve this, the Delphi method was employed to identify and assess the strengths, weaknesses, opportunities, and threats (SWOT) associated with the application of indigenous knowledge. A subsequent SWOT analysis was performed to develop effective strategies for leveraging this knowledge in desertification mitigation and water and soil conservation. Furthermore, the Quantitative Strategic Planning Matrix (QSPM) was applied to prioritize these strategies and justify their relative significance. Results from the internal factors analysis indicated that indigenous knowledge, with a final score of 54.3 points, represents a substantial strength, particularly due to long-standing adaptation to local climatic conditions, effective soil protection through native vegetation, and water-efficient agricultural practices. In contrast, weaknesses, scoring 64.1 points, were mainly related to the oral transmission of knowledge and limited intergenerational transfer. The external factors analysis revealed that opportunities (66.3 points) slightly outweigh threats (66.1 points), particularly regarding community participation, institutional support, and integration with modern scientific knowledge. Based on these findings, a total of 24 operational strategies were identified across four categories (SO, WO, ST, and WT) with an emphasis on integrating indigenous knowledge with modern technologies, revitalizing traditional water and soil management systems, and institutionalizing participatory natural resource management https://aridbiom.yazd.ac.ir/article_4056.html به منظور تحلیل فراوانی وقوع و دوره بازگشت بارندگی‌های یک منطقه، از منحنی‌های شدت–مدت–فراوانی بارش استفاده می‌شود. در تحقیق حاضر، هدف استخراج منحنی‌های شدت–مدت–فراوانی ایستگاه‌های باران‌سنجی و سینوپتیک حوزه آبخیز سانیج (ایستگاه بیدآخوید) می‌باشد. برای این منظور از داده‌های بارش ۲۴ ساعته و بارش لحظه‌ای ایستگاه مذکور استفاده گردید. برای تهیه منحنی‌های مورد نظر به کمک بارش‌های ۲۴ ساعته از روش قهرمان استفاده شد. همچنین، استخراج منحنی‌های مطالعاتی به کمک بارش لحظه‌ای با بهره‌گیری از نرم‌افزار ایزی فیت و به کمک توابع انتخابی صورت گرفته و منحنی‌های شدت–مدت–فراوانی (IDF) برای تداوم‌های مختلف تا ۲۴ ساعت و دوره بازگشت‌های ۲ تا ۲۵۰ سال استخراج شد. نتایج نشان داد شدت بارش در نیم‌سال دوم (پاییز و زمستان) به‌طور میانگین حدود ۶۰ درصد بیشتر از نیم‌سال اول (بهار و تابستان) است و این اختلاف در دوره‌های بازگشت بلندمدت و تداوم‌های طولانی‌تر بیشتر است. میانگین سالانه شدت بارش نیز حدود ۳۵ درصد بیش از نیم‌سال اول برآورد شد. از آنجا که بخش قابل توجهی از بارش‌های نیم‌سال دوم به صورت برف است و نقش محدودی در تولید سیلاب دارد، بررسی دقیق‌تر فصلی بارش‌ها برای تحلیل رواناب ضروری است. نتایج نشان می‌دهد که عدم تفکیک زمانی–فصلی بارش می‌تواند منجر به خطای بیش از ۳۰ درصد در برآورد شدت بارش مؤثر گردد. بنابراین، کاربرد روش‌های ترکیبی از جمله تحلیل‌های ماهواره‌ای، داده‌های محلی و پرسشگری از ساکنان منطقه، در تفکیک بارش‌های مؤثر و غیرمؤثر در تولید سیلاب توصیه می‌شود. این رویکردها می‌توانند دقت مدل‌سازی‌های هیدرولوژیکی و مدیریت منابع آب و کنترل سیلاب را در منطقه بهبود دهند. https://aridbiom.yazd.ac.ir/article_4057.html This study investigated the effect of two plant growth promoting bacteria B. amyloliquefaciens and B. halotolerans on physiological, biochemical and functional traits of safflower (Carthamus tinctorius L.) under drought and dust stress. A factorial experiment was conducted in a randomized complete block design with different treatments including individual and combined inoculation of the two bacteria, irrigation at three levels of irrigation period (every 4, 6 and 8 days) and dust at two levels. The results showed that the simultaneous effect of drought and dust on safflower was more destructive than the effect of each alone. Meanwhile, dust had a less negative effect on safflower than drought. Drought reduced the absorption of mineral elements, soluble sugars, chlorophyll b, seed weight per plant and dry weight of safflower and increased phenol, proline and carotenoids. In contrast, dust only reduced the amount of phosphorus and soluble sugars in safflower and increased ascorbic acid and phenol. Bacterial inoculation improved the physiological and functional conditions of safflower in most cases, while the combination of two bacteria performed better than the individual inoculation of bacteria in most of the measured traits. While B. halotolerans and the combination of two bacteria performed better in increasing safflower seed weight, the dry weight of the plant increased more with B. amyloliquefaciens inoculation. The findings of this study emphasize the importance of using simultaneous combinations of plant growth-promoting bacteria as a sustainable biological solution to improve the growth of plants that often face multiple stresses.