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Riparian ecosystems comprise less than 2% of the landscape in the arid western United States, yet they provide habitat and resources to over half of arid‐land wildlife species, including a broad diversity of anurans (frogs and toads). Despite this, relatively few studies describe riparian herpetofaunal communities in the Southwest, and remote wilderness areas are particularly undersurveyed.We employed passive acoustic monitoring to capture anuran advertisement calls in wilderness area tributaries of the Verde River, Arizona, USA. In the spring and summer of 2021 and 2022, 13–29 autonomous recording units (ARUs) were deployed along perennial, intermittent and ephemeral tributary stream reaches. We characterized sites based on the per cent of pool, riffle, run and side channel habitat within 100 m of each ARU and quantified substrate, wetted channel width and canopy cover. To relate anuran occupancy to environmental and hydrological variables, we evaluated acoustic detection data using single‐species, single‐season occupancy models.Four species were detected in this study: canyon treefrog (Hyla arenicolor), red‐spotted toad (Anaxyrus punctatus), Woodhouse's toad (Anaxyrus woodhousii) and non‐native American bullfrog (Lithobates catesbeianus), with canyon treefrog being the most ubiquitous species observed. Vocal activity of canyon treefrog was higher at perennial and intermittent sites compared to ephemeral sites, and the presence of pools was most strongly associated with canyon treefrog occupancy.Persistent, slow‐moving water best predicted the presence of breeding canyon treefrogs. Notably, this study did not detect several species with historical records in the middle Verde River catchment, including Arizona toad (Anaxyrus microscaphus) and northern leopard frog (Lithobates pipiens).Given climate change‐related flow declines and intensifying demands for water in arid lands globally, maintaining stream flows that provide consistent and suitable hydroregimes for anuran breeding and larval development is of increasing importance. Determining habitat use and flow regimes necessary to support anuran populations can aid in prioritization of conservation actions related to water management and predict how changes in water availability may impact stream‐breeding anurans. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusions Warm deserts are characterised by water shortages and high temperature extremes. A commonly reported adaptive strategy in such environments is maximisation of photosynthetic capacity, which allows plants to achieve positive carbon budgets by taking advantage of short periods of water availability and non‐inhibitory temperatures. Considering the well‐supported interspecific covariation between photosynthetic capacity and leaf N concentration, we tested the hypothesis that environmental aridity is related to an elevated leaf nitrogen content.53 locations in the transitional zone spanning the Mediterranean and the Sahara Desert in Morocco. The mean maximal temperature (Tmax) within the area varied between 35.7°C and 43.5°C, and the mean annual precipitation (MAP) was between 12 and 246 mm.225 vascular species representative of local vegetation.Leaf samples were collected along a regional aridity gradient and preserved in herbarium presses. The leaf mass per area (LMA) and N concentrations expressed on leaf mass (Nmass) and area (Narea) basis were determined. We also obtained LMA and Nmass values for 6711 species from a worldwide database for comparative analysis.Significant increases in mean LMA, Nmass and Narea accompanied the increase in Tmax and the decrease in MAP in woody species and in non‐graminoid herbs, but not in graminoids. Considering the overall aridity of our sampling area, we compared the Nmass values of Moroccan plants with those from a worldwide database. We found that at a common LMA, the Moroccan plants showed on average elevated Nmass relative to global values.These two lines of evidence: regional gradient and global comparison confirm that hot deserts select for high leaf N content. This result suggests the direction of natural selection that will accompany future climate warming and habitat aridification. [ABSTRACT FROM AUTHOR]

AbstractAn accurate investigation is needed to determine if the selected location, the tree species, and the applied treatments can support a successful seedling establishment and outplanting performance to ensure the success of large-scale tree-planting initiatives. To shed light on the growth pattern of the trees used in the Green Belt Project plantations in the Mongolian steppe, we analysed the biomass allocation in the stem and roots of Ulmus pumila in terms of ring width, considering different management techniques involving irrigation and fertilisation. We found that the root and shoot ring width of U. pumila followed a bell-shaped curve and reached maximum values after three or four years from seedling outplanting. Moreover, our data confirm that increasing watering regimes may enhance plant growth, especially the root system, while fertilisation did not show a positive effect independently of the fertilisation type (i.e. NPK and compost). Our data allowed us to develop a predictive regression model that could be used with other species and in different environmental conditions to forecast stem and root tree growth and to simulate afforestation performances in different climatic conditions. [ABSTRACT FROM AUTHOR]

Despite quinoa (Chenopodium quinoa Willd.) gaining international popularity in the early 21st century for its nutritional benefits, there remains a critical need to optimize its cultivation practices in arid regions. Current research often overlooks the combined effects of supplemental irrigation and foliar treatments on quinoa's yield and water efficiency, particularly under challenging environmental conditions like those in Borg El-Arab, Egypt. Field studies were conducted in Borg El-Arab, Alexandria, Egypt, during the winter seasons of 2021/2022 and 2022/2023 to determine the influence of supplemental irrigation (rainfed, 2000, and 4000 m3/hectare, respectively) and foliar spraying of sodium silicate (control, 200, and 400 ppm) on yield, yield components, seed quality, and water usage efficiency in quinoa cv. Chibaya grown in arid lands. Three replications were used in a split-plot design. The main plots were designated for irrigation, while the subplots were designated for foliar spraying. The results indicate that applying irrigation at a rate of 4000 m3/hectare significantly increased leaf dry weight per plant by 23.5%, stem dry weight per plant by 18.7%, total dry weight per 25 plants by 21.4%, leaf area per plant by 19.2%, and straw yield by 26.8% compared to the control treatment. There were no significant differences between irrigation with the rate of 4000 m3 or 2000 m3/hectare on biological yield kg/hectare, N (%), P (mg/100 g), and protein (%). The utilization of sodium silicate had no significance on all studied features except for straw yield kg ha−1 at the rate of 200 or 400 ppm. The results regarding the RAPD1 primer revealed that the 2000+0 silicon treatment was the only treatment that resemble the control with no up- or downregulated fragment. Moreover, 20 upregulated fragments were observed in all treatments, while 19 DNA fragments were downregulated. Furthermore, the results obtained regarding the RAPD2 primer revealed that 53 fragments were upregulated and 19 downregulated. Additionally, the RAPD3 primer demonstrated that 40 DNA fragments were upregulated, whereas 18 downregulated DNA fragments were detected. It may be inferred that the application of irrigation at a rate of 4000 m3 ha−1 might serve as a supplemental irrigation method. Spraying sodium silicate at a 400 mg L−1 concentration could alleviate the dry climate on the Egyptian shore. [ABSTRACT FROM AUTHOR]

Roadsides are home to a diverse range of species with varying geographic origins. The aim of the current study is to describe the floristic diversity of roadside vegetation in western Saudi Arabia, as well as to examine the impact of altitude on this diversity. Roadsides were divided into belts according to their elevations above sea level. The floristic composition, the exotic aliens, weeds, life forms, and the chorology of each belt were determined. The study showed that the amount of rain, temperature, heavy traffic, and altitude have a major role in the distribution of these plants. The total species recorded on both roadsides was 228 species, where the difference between the two roads was not only in species number but also in the floristic composition. In the current study, two endemic species, Kickxia pseudoscoparia and Euphorbia ammak, were recorded. The most frequent species overall was Forsskaolea tenacissima, which was found in all studied belts, followed by Aerva javanica, which was found in 87% of the studied belts. The therophytes dominated the other life forms by 44.8%, followed by chamerophytes which exhibited about 26.5%. Primarily, this study will improve the understanding of the distribution of plants on roadsides in the study area and help to manage alien and invasive species. [ABSTRACT FROM AUTHOR]

Orenburg Region is located in the South Urals, mostly in the steppe zone and is characterised by various landscapes suitable for many Chenopodiaceae. The species of Chenopodiaceae are present in all major plant communities (saline vegetation, steppes, on limestone, chalk and sand, and as degraded or ruderal communities). In the steppe zone, many native subshrubby species (Atriplex cana, Caroxylon laricinum, Suaeda physophora) playing a crucial role in semi-deserts (known as southern steppes in the recent Russian literature) located southwards of Orenburg Region are locally found, and several annuals (Salicornia perennans, Suaeda spp.) are most common dominants in plant communities. Some typical semi-desert species (Kalidium foliatum, Bassia hyssopifolia, Soda foliosa, Spirobassia hirsuta) are found in the easternmost part of the region.We compiled a checklist of Chenopodiaceae in Orenburg Region, with two new records (Chenopodium virgatum, Corispermum laxiflorum), based on our critical revision, comprehensive inventory of herbarium specimens and documented observations and field research. In total, we report 76 species in the Region, which is the third-highest number of the Chenopodiaceae species compared with other administrative territories of European Russia, North Caucasus and West Siberia. Alien and native taxa are distinguished. Zonal patterns of species distributions are confirmed. A preliminary conservation status is proposed for each native species. Three species are recommended for exclusion from the Red Data Book of Orenburg Region: Petrosimonia triandra (because of its extensive distribution), Kalidium foliatum and Anabasis salsa (because of the lack of actual threat to their populations). Arthrophytum lehmannianum and Salsola rosacea are considered threatened (Vulnerable) because of their restricted occurrence and population size and because their localities are under anthropogenic pressure. Atriplex hortensis, Atriplex rosea, Chenopodium acuminatum, C. karoi, C. praetericola, C. vulvaria, Climacoptera affinis, C. crassa, Halimocnemis karelinii, Salsola paulsenii and Xylosalsola arbuscula are excluded from the checklist, based on various reasons as discussed in the paper. Point distribution maps are provided for each species. Agriophyllum pungens (Vahl) Link is accepted as the correct authorship instead of "M.Bieb. ex C.A.Mey."

Hot deserts impose extreme conditions on plants growing in arid soils. Deserts are expanding due to climate change, thereby increasing the vulnerability of ecosystems and the need to preserve them. Arbuscular mycorrhizal fungi (AMF) improve plant fitness by enhancing plant water/nutrient uptake and stress tolerance. However, few studies have focused on AMF diversity and community composition in deserts, and the soil and land use parameters affecting them. This study aimed to comprehensively describe AMF ecological features in a 5,000 km2 arid hyperalkaline region in AlUla, Saudi Arabia. We used a multimethod approach to analyse over 1,000 soil and 300 plant root samples of various species encompassing agricultural, old agricultural, urban and natural ecosystems. Our method involved metabarcoding using 18S and ITS2 markers, histological techniques for direct AMF colonization observation and soil spore extraction and observation. Our findings revealed a predominance of AMF taxa assigned to Glomeraceae, regardless of the local conditions, and an almost complete absence of Gigasporales taxa. Land use had little effect on the AMF richness, diversity and community composition, while soil texture, pH and substantial unexplained stochastic variance drove these compositions in AlUla soils. Mycorrhization was frequently observed in the studied plant species, even in usually non-mycorrhizal plant taxa (e.g. Amaranthaceae, Urticaceae). Date palms and Citrus trees, representing two major crops in the region, however, displayed a very low mycorrhizal frequency and intensity. AlUla soils had a very low concentration of spores, which were mostly small. This study generated new insight on AMF and specific behavioral features of these fungi in arid environments. [ABSTRACT FROM AUTHOR]

Estimating soil erodible fraction based on basic soil properties in arid lands is a valuable research topic in the field of soil science and land management. The Proximal Sensing (PS) technique offers a non-destructive and efficient method to assess wind erosion potential in arid regions. By using Partial Least Squares Regression (PLSR) and Support Vector Machine (SVM) models and combining soil texture and chemical properties, determined through Visible-Near Infrared (vis-NIR) spectroscopy in 96 soil samples, this study aims to predict soil erodibility, soil organic matter (SOM), and calcium carbonate equivalent (CaCO3) in arid lands located in Elkobaneyya Valley, Aswan Governorate, Egypt. Results showed that the soil erodibility fraction (EF-Factor) had the highest values and possessed a strong relationship between slope and SOM of 0.01% in determining soil erodibility. The PLSR model performed better than SVM for estimating SOM, CaCO3, and EF-Factor. Furthermore, the results showed that the spectral responses of CaCO3 were observed in separate places in the wavelengths of 570, 649, 802, 1161, 1421, 1854, and 2362 nm, and the wavelengths with SOM parameter were 496, 658, 779, 1089, 1417, 1871, and 2423 nm. The EF-factor shows the highest significant correlation with spectral reflectance values at 526, 688, 744, 1418, 1442, 2292, and 2374 nm. The accuracy and performance of the PLSR model in estimating the EF-Factor using spectral reflectance data and the distribution of data points for both the calibration and validation data-sets indicate a good accuracy of the PLSR model, with RMSE values of 0.0921 and 0.0836 Mg h MJ−1 mm−1, coefficient of determination (R2) values of 0.931 and 0.76, and RPD values of 2.168 and 2.147, respectively. [ABSTRACT FROM AUTHOR]

Increased occurrence, size, and intensity of fire result in significant but variable changes to hydrology and material retention in watersheds with concomitant effects on stream biogeochemistry. In arid regions, seasonal and episodic precipitation results in intermittency in flows connecting watersheds to recipient streams that can delay the effects of fire on stream chemistry. We investigated how the spatial extent of fire within watersheds interacts with variability in amount and timing of precipitation to influence stream chemistry of three forested, montane watersheds in a monsoonal climate and four coastal, chaparral watersheds in a Mediterranean climate. We applied state-space models to estimate effects of precipitation, fire, and their interaction on stream chemistry up to five years following fire using 15 + years of monthly observations. Precipitation alone diluted specific conductance and flushed nitrate and phosphate to Mediterranean streams. Fire had positive and negative effects on specific conductance in both climates, whereas ammonium and nitrate concentrations increased following fire in Mediterranean streams. Fire and precipitation had positive interactive effects on specific conductance in monsoonal streams and on ammonium in Mediterranean streams. In most cases, the effects of fire and its interaction with precipitation persisted or were lagged 2–5 years. These results suggest that precipitation influences the timing and intensity of the effects of fire on stream solute dynamics in aridland watersheds, but these responses vary by climate, solute, and watershed characteristics. Time series models were applied to data from long-term monitoring that included observations before and after fire, yielding estimated effects of fire on aridland stream chemistry. This statistical approach captured effects of local-scale temporal variation, including delayed responses to fire, and may be used to reduce uncertainty in predicted responses of water quality under changing fire and precipitation regimes of arid lands. [ABSTRACT FROM AUTHOR]

Introduction Analysis of the spatial and temporal trends of precipitation is pertinent for the future sustainable management of water resources. Urbanization and climate change affected local rainfall and intensity. As rainfall characteristics are often used to design urban drainage systems, so watershed modeling, and estimate of the flood properties, updating and reviewing rainfall characteristics is necessary. The Intensity-Duration-Frequency (IDF) curves are a suitable tool to estimate the threshold values of precipitation in different return periods. IDF curves should be prepared based on the long-term rainfall statistics in each region and can change under the influence of climate change. These curves which indicate the frequency and maximum intensity of annual rainfall in the different return periods are suitable tools for planning and managing the water resources. IDF curves are broadly used for different purposes, such as the design of flood control and diversion structures in the cities. The main purpose of this research is to investigate the effect of climate change on temperature, precipitation, and IDF curves in the different return periods in an arid environment. Materials and Methods In this research, the effect of climate change on IDF curves was investigated in Kashan City as a dry region. Kashan city with an area of 9647 km2 is located in the northern part of the Isfahan Province. In this study, RCP8.5, RCP4.5, and RCP2.6 scenarios (which are introduced as optimistic, intermediate, and pessimistic scenarios) reported in the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC), were used to predict the impacts of climate change on temperature and precipitation changes. Then, IDF curves were calculated evaluated, and compared for the basic (1993-2017) and future periods (2011-2070). To examine the impact of climate change on the rainfall intensity patterns, it is necessary to extract IDF curves in different climate conditions. Bell's method is a usual method for extraction of the IDF curves, which was promoted by Gharehman-Abkhezr in Iran. In this study, the latest promoted relationships developed were for the desert and southern regions (e.g;Nizar-Salfachgan, Kuhpayeh, Herat, and Jiroft basins in the central Provinces, Qom, Isfahan, Kerman, and Yazd) have been presented and used to extract IDF curves. To investigate the effects of climate change on IDF curves, first, the base period curves were extracted via rainfall data measured at the Kashan synoptic station. Then, using the new climate scenarios (RCP8.5, RCP4.5, and RCP2.6) and the output data of the LARS exponential microscale model, the IDF curves were extracted for different climate scenarios in the future (2011-2030), (2031-2050), and (2051-2070). Finally, the results of these curves were compared with the base period. Results and Discussion According to the results, for the base period, the precipitation and temperature data were predicated with an acceptable accuracy by the LARS model. The accuracy of the model has been higher in estimating the minimum and maximum temperature. the Nash and explanation coefficients for the maximum and minimum temperatures were 0.99 and 0.99, respectively. While, the explanatory and Nash coefficients for precipitation data were 0.95 and 0.93, respectively. Based on the results, the rainfall intensity will have fewer changes compared to the base period for long-term duration rainfall compared to short-duration rainfall (less than four hr. The maximum changes are related to rainfalls with a duration of less than one hour, whereas the minimum changes are predicted for 24- hr rainfalls. For all studied scenarios, a significant difference (P<0.05) was predicted between the average rainfall intensity of 0.17 to 24 hr in the region. As in the two-year return period and under the 2.6 scenario, rainfall intensity was increased from 10.75 to 30.54 mm hr-1 for the duration time of 0.17 hr. Conclusion An increase in air temperature, decrease in rainfall, change in the rainfall pattern, decrease in river discharge, and increase in sudden floods, followed by an increase in soil erosion, and a decrease in the amount of agricultural products are the results of climate change. Therefore, the long-term analysis and monitoring of climatic conditions can be very effective for crisis management caused by climate changes such as floods and droughts. Based on the results, the effect of climate change on the intensity of short-term rainfall is greater than long-term duration rainfall, as the intensity of short-term rainfall will increase more than long-term rainfalls. [ABSTRACT FROM AUTHOR]

Wheat is one of the most important cereal crops in Egypt and all over the world. Its productivity is adversely affected by drought due to deficient irrigation to provide nutrients required for plant growth. In a field experiment, silicon foliar applications at concentrations of 0, 200, and 400 mg L−1 were performed at different irrigation rates ranging from 1000 to 4000 m3 ha−1 to assess water irrigation productivity and wheat crop yield in a calcareous soil under arid climate conditions. Increased irrigation rates led to a significant increase in soil nutrient dynamics, as well as in the number and weight of grains per spike, leaf area index, grain yield, straw yield, and biological yield, with the exception of the weight of 1000 grains. Spraying with sodium silicate had a significant impact on grain yield and harvest index but did not significantly impact the other traits. Furthermore, the interaction between irrigation and silicate application rates showed significance only for grain yield, the number of spikes/m2, and the harvest index. Applying three times irrigation could produce the highest nutrient retention, wheat yield, and water irrigation productivity. No significance was observed between 3000 m3 ha−1 and 4000 m3 ha−1 irrigation, indicating a saving of 25% of applied irrigation water. It can be concluded that applying irrigation at 3000 m3 ha−1 could be a supplemental irrigation strategy. High wheat grain yield can be achieved under deficit irrigation (3000 m3 ha−1) on the northwestern coast of Egypt with an arid climate by spraying crops with sodium silicate at a rate of 400 mg L−1. [ABSTRACT FROM AUTHOR]

Background: Orenburg Region is located in the South Urals, mostly in the steppe zone and is characterised by various landscapes suitable for many Chenopodiaceae. The species of Chenopodiaceae are present in all major plant communities (saline vegetation, steppes, on limestone, chalk and sand, and as degraded or ruderal communities). In the steppe zone, many native subshrubby species (Atriplex cana, Caroxylon laricinum, Suaeda physophora) playing a crucial role in semi-deserts (known as southern steppes in the recent Russian literature) located southwards of Orenburg Region are locally found, and several annuals (Salicornia perennans, Suaeda spp.) are most common dominants in plant communities. Some typical semi-desert species (Kalidium foliatum, Bassia hyssopifolia, Soda foliosa, Spirobassia hirsuta) are found in the easternmost part of the region. New information: We compiled a checklist of Chenopodiaceae in Orenburg Region, with two new records ( Chenopodium virgatum, Corispermum laxiflorum), based on our critical revision, comprehensive inventory of herbarium specimens and documented observations and field research. In total, we report 76 species in the Region, which is the third-highest number of the Chenopodiaceae species compared with other administrative territories of European Russia, North Caucasus and West Siberia. Alien and native taxa are distinguished. Zonal patterns of species distributions are confirmed. A preliminary conservation status is proposed for each native species. Three species are recommended for exclusion from the Red Data Book of Orenburg Region: Petrosimonia triandra (because of its extensive distribution), Kalidium foliatum and Anabasis salsa (because of the lack of actual threat to their populations). Arthrophytum lehmannianum and Salsola rosacea are considered threatened (Vulnerable) because of their restricted occurrence and population size and because their localities are under anthropogenic pressure. Atriplex hortensis, Atriplex rosea, Chenopodium acuminatum, C. karoi, C. praetericola, C. vulvaria, Climacoptera affinis, C. crassa, Halimocnemis karelinii, Salsola paulsenii and Xylosalsola arbuscula are excluded from the checklist, based on various reasons as discussed in the paper. Point distribution maps are provided for each species. Agriophyllum pungens (Vahl) Link is accepted as the correct authorship instead of "M.Bieb. ex C.A.Mey." [ABSTRACT FROM AUTHOR]

In arid environments, prospecting cultivable land is challenging due to harsh climatic conditions and vast, hard-to-access areas. However, the soil is often bare, with little vegetation cover, making it easy to observe from above. Hence, remote sensing can drastically reduce costs to explore these areas. For the past few years, deep learning has extended remote sensing analysis, first with Convolutional Neural Networks (CNNs), then with Vision Transformers (ViTs). The main drawback of deep learning methods is their reliance on large calibration datasets, as data collection is a cumbersome and costly task, particularly in drylands. However, recent studies demonstrate that ViTs can be trained in a self-supervised manner to take advantage of large amounts of unlabelled data to pre-train models. These backbone models can then be finetuned to learn a supervised regression model with few labelled data.In our study, we trained ViTs in a self-supervised way with a 9500 km2 satellite image of dry-lands in Saudi Arabia with a spatial resolution of 1.5 m per pixel. The resulting models were used to extract features describing the bare soil and predict soil attributes (pH H2O, pH KCl, Si composition). Using only RGB data, we can accurately predict these soil properties and achieve, for instance, an RMSE of 0.40 ± 0.03 when predicting alkaline soil pH. We also assess the effectiveness of adding additional covariates, such as elevation. The pretrained models can as well be used as visual features extractors. These features can be used to automatically generate a clustered map of an area or as input of random forests models, providing a versatile way to generate maps with limited labelled data and input variables.

Introduction Analysis of the spatial and temporal trends of precipitation is pertinent for the future sustainable management of water resources. Urbanization and climate change affected local rainfall and intensity. As rainfall characteristics are often used to design urban drainage systems, so watershed modeling, and estimate of the flood properties, updating and reviewing rainfall characteristics is necessary. The Intensity-Duration-Frequency (IDF) curves are a suitable tool to estimate the threshold values of precipitation in different return periods. IDF curves should be prepared based on the long-term rainfall statistics in each region and can change under the influence of climate change. These curves which indicate the frequency and maximum intensity of annual rainfall in the different return periods are suitable tools for planning and managing the water resources. IDF curves are broadly used for different purposes, such as the design of flood control and diversion structures in the cities. The main purpose of this research is to investigate the effect of climate change on temperature, precipitation, and IDF curves in the different return periods in an arid environment. Materials and Methods In this research, the effect of climate change on IDF curves was investigated in Kashan City as a dry region. Kashan city with an area of 9647 km2 is located in the northern part of the Isfahan Province. In this study, RCP8.5, RCP4.5, and RCP2.6 scenarios (which are introduced as optimistic, intermediate, and pessimistic scenarios) reported in the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC), were used to predict the impacts of climate change on temperature and precipitation changes. Then, IDF curves were calculated evaluated, and compared for the basic (1993-2017) and future periods (2011-2070). To examine the impact of climate change on the rainfall intensity patterns, it is necessary to extract IDF curves in different climate conditions. Bell's method is a usual method for extraction of the IDF curves, which was promoted by Gharehman-Abkhezr in Iran. In this study, the latest promoted relationships developed were for the desert and southern regions (e.g;Nizar-Salfachgan, Kuhpayeh, Herat, and Jiroft basins in the central Provinces, Qom, Isfahan, Kerman, and Yazd) have been presented and used to extract IDF curves. To investigate the effects of climate change on IDF curves, first, the base period curves were extracted via rainfall data measured at the Kashan synoptic station. Then, using the new climate scenarios (RCP8.5, RCP4.5, and RCP2.6) and the output data of the LARS exponential microscale model, the IDF curves were extracted for different climate scenarios in the future (2011-2030), (2031-2050), and (2051-2070). Finally, the results of these curves were compared with the base period. Results and Discussion According to the results, for the base period, the precipitation and temperature data were predicated with an acceptable accuracy by the LARS model. The accuracy of the model has been higher in estimating the minimum and maximum temperature. the Nash and explanation coefficients for the maximum and minimum temperatures were 0.99 and 0.99, respectively. While, the explanatory and Nash coefficients for precipitation data were 0.95 and 0.93, respectively. Based on the results, the rainfall intensity will have fewer changes compared to the base period for long-term duration rainfall compared to short-duration rainfall (less than four hr. The maximum changes are related to rainfalls with a duration of less than one hour, whereas the minimum changes are predicted for 24- hr rainfalls. For all studied scenarios, a significant difference (P

This article discusses the breeding behavior of Canyon treefrogs in relation to spring floods and warming nights in the southwestern United States. The study found that the timing of the frogs' breeding activity, such as calling and chorusing, occurs after spring flows recede during lower base flows. The article emphasizes the importance of natural flow regimes and highlights the potential negative impacts of human-mediated alterations, such as dams and diversions, on the breeding and population of stream-breeding anurans. The study suggests that maintaining natural flows or mimicking natural flow regimes can promote the persistence of these species. Future research should investigate additional bioclimatic variables and the effects of changing climate conditions on the breeding behavior of Canyon treefrogs. [Extracted from the article]

Increased food, feed, and biofuel demands of the future will require a greater reliance upon crop production systems in arid and semi‐arid regions around the world. Diminishing freshwater resources and hotter and drier climatic conditions will also necessitate the use of highly drought tolerant and water‐use efficient crops. Cactus pear (Opuntia ficus‐indica) is a low‐water input, climate‐resilient crop capable of high biomass production due to its use of crassulacean acid metabolism (CAM). Cactus pear produces both food and forage/fodder, a wide variety of high‐value byproducts, and serves as a bioenergy feedstock for biogas or bioethanol production. Here, we evaluated the biomass productivity of 14 Opuntia spp. accessions from the National Arid Land Plant Genetic Resources Unit (NALPGRU) in Parlier, CA under semi‐arid conditions with a planting density of 6667 plants ha−1 over a 3‐year period to identify high‐yielding biomass producers. Mean annual cladode fresh weight (CFW) (73.7 Mg ha−1 year−1), cladode dry weight (CDW) (5.2 Mg ha−1 year−1), and cladode count (CC) (10.5 cladodes plant−1) increased by 2.9‐, 2.8‐, and 2.8‐fold in year 3 compared with year 1. PARL 845, hybrid no. 46 (O. ficus‐indica × O. lindheimerii), showed the highest annual mean CFW (152.8 Mg ha−1 year−1), CDW (13.3 Mg ha−1 year−1), CC (22.1 cladodes plant−1), and dry matter content (DMC, 11.2%) among all accessions tested. Non‐hybrid accessions PARL 242 (O. cochenillifera), PARL 582 (Opuntia sp.), and PARL 584 (Opuntia sp.) showed 100% cladode establishment rates and CDW productivity of >6 Mg ha−1 year−1. Such biomass productivity results indicate that cactus pear displays great potential as a crop with many uses with lower water inputs than conventional crops for arid and semi‐arid environments. [ABSTRACT FROM AUTHOR]

Drylands, comprising semi‐arid, arid, and hyperarid regions, cover approximately 41% of the Earth's land surface and have expanded considerably in recent decades. Even under more optimistic scenarios, such as limiting global temperature rise to 1.5°C by 2100, semi‐arid lands may increase by up to 38%. This study provides an overview of the state‐of‐the‐art regarding changing aridity in arid regions, with a specific focus on its effects on the accumulation and availability of carbon (C), nitrogen (N), and phosphorus (P) in plant–soil systems. Additionally, we summarized the impacts of rising aridity on biodiversity, service provisioning, and feedback effects on climate change across scales. The expansion of arid ecosystems is linked to a decline in C and nutrient stocks, plant community biomass and diversity, thereby diminishing the capacity for recovery and maintaining adequate water‐use efficiency by plants and microbes. Prolonged drought led to a −3.3% reduction in soil organic carbon (SOC) content (based on 148 drought‐manipulation studies), a −8.7% decrease in plant litter input, a −13.0% decline in absolute litter decomposition, and a −5.7% decrease in litter decomposition rate. Moreover, a substantial positive feedback loop with global warming exists, primarily due to increased albedo. The loss of critical ecosystem services, including food production capacity and water resources, poses a severe challenge to the inhabitants of these regions. Increased aridity reduces SOC, nutrient, and water content. Aridity expansion and intensification exacerbate socio‐economic disparities between economically rich and least developed countries, with significant opportunities for improvement through substantial investments in infrastructure and technology. By 2100, half the world's landmass may become dryland, characterized by severe conditions marked by limited C, N, and P resources, water scarcity, and substantial loss of native species biodiversity. These conditions pose formidable challenges for maintaining essential services, impacting human well‐being and raising complex global and regional socio‐political challenges. [ABSTRACT FROM AUTHOR]

Prior to the commercial nitrogen fertilizer production in 1919, all the world's terrestrial and aquatic carbon was supported by nitrogen fixation. Annual N deposition to semi‐arid lands and temperate forests is less than 5 kg/ha‐year and 10 kg/ha, respectively. Plant and soil C/N ratios range from 9.9 to 29.8 and 9 to 14, respectively. In an equilibrium, sustainable ecosystem where N is not removed from soil pools and is only dependent on annual N inputs, maximum C sequestration rates are approximately 3.25 kg to 46 kg/ha for arid ecosystems and 23 to 101 kg/ha for forest ecosystems. Commercial N applications range from approximately 70 to 160 kg/ha‐year. Managed nitrogen fixation rates range from approximately 50 to 130 kg N/ha‐year. For each additional kg N‐entering forests, the additional C is approximately 13 kg. N‐fixing plants range from alder and lupines in the arctic, to Prosopis and Acacias in semi‐arid lands and the large trees Inga and Pentaclethra in tropical rainforests. If N‐fixing plants achieving 50 kg N/ha‐year were planted on the equivalent of a 447 km square, on six continents, the IEA target of 1.7Gt CO2 (0.72 Gt of carbon) capture capacity by 2030 https://www.ief.org/news/whats‐the‐target‐for‐carbon‐sequestration‐and‐how‐do‐we‐get‐there could be achieved. [ABSTRACT FROM AUTHOR]

A major restriction in predicting plant community response to future climate change is a lack of long-term data needed to properly assess species and community response to climate and identify a baseline to detect climate anomalies. Here, we use a 106-year dataset on a Sonoran Desert plant community to test the role of extreme temperature and precipitation anomalies on community dynamics at the decadal scale and over time. Additionally, we tested the climate sensitivity of 39 desert plant species and whether sensitivity was associated with growth form, longevity, geographic range, or local dominance. We found that desert plant communities had shifted directionally over the 106 years, but the climate had little influence on this directional change primarily due to nonlinear shifts in precipitation anomalies. Decadal-scale climate had the largest impact on species richness, species relative density, and total plant cover, explaining up to 26%, 45%, and 55% of the variance in each, respectively. Drought and the interaction between the frequency of freeze events and above-average summer precipitation were among the most influential climate factors. Increased drought frequency and wetter periods with frequent freeze events led to larger reductions in total plant cover, species richness, and the relative densities of dominant subshrubs Ambrosia deltoidea and Encelia farinosa. More than 80% of the tested species were sensitive to climate, but sensitivity was not associated with a species' local dominance, longevity, geographic range, or growth form. Some species appear to exhibit demographic buffering, where when they have a higher sensitivity to drought, they also tend to have a higher sensitivity to favorable (i.e., wetter and hotter) conditions. Overall, our results suggest that, while decadal-scale climate variation substantially impacts these desert plant communities, directional change in temperature over the last century has had little impact due to the relative importance of precipitation and drought. With projections of increased drought in this region, we may see reductions in total vegetation cover and species richness due to the loss of species, possibly through a breakdown in their ability to demographically buffer climatic variation, potentially changing community dynamics through a change in facilitative and competitive processes. [ABSTRACT FROM AUTHOR]

The county (city) located on the northern slope of the Kunlun Mountains is the primary area to solidify and extend the success of Xinjiang Uygur Autonomous Region, China in poverty alleviation. Its Sustainable Development Goals (SDGs) are intertwined with the concerted economic and social development of Xinjiang and the objective of achieving shared prosperity within the region. This study established a sustainable development evaluation framework by selecting 15 SDGs and 20 secondary indicators from the United Nations' SDGs. The aim of this study is to quantitatively assess the progress of SDGs at the county (city) level on the northern slope of the Kunlun Mountains. The results indicate that there are substantial variations in the scores of SDGs among the nine counties and one city located on the northern slope of the Kunlun Mountains. Notable high scores of SDGs are observed in the central and eastern regions, whereas lower scores are prevalent in the western areas. The scores of SDGs, in descending order, are as follows: 62.22 for Minfeng County, 54.22 for Hotan City, 50.21 for Qiemo County, 42.54 for Moyu County, 41.56 for Ruoqiang County, 41.39 for Qira County, 39.86 for Lop County, 38.25 for Yutian County, 38.10 for Pishan County, and 36.87 for Hotan County. The performances of SDGs reveal that Hotan City, Lop County, Minfeng County, and Ruoqiang County have significant sustainable development capacity because they have three or more SDGs ranked as green color. However, Hotan County, Moyu County, Qira County, and Yutian County show the poorest performance, as they lack SDGs with green color. It is important to establish and enhance mechanisms that can ensure sustained income growth among poverty alleviation beneficiaries, sustained improvement in the capacity of rural governance, and the gradual improvement of social security system. These measures will facilitate the effective implementation of SDGs. Finally, this study offers a valuable support for governmental authorities and relevant departments in their decision-making processes. In addition, these results hold significant reference value for assessing SDGs at the county (city) level, particularly in areas characterized by low levels of economic development. [ABSTRACT FROM AUTHOR]

Rapid urbanization across hot arid environments transforms local microclimates, yet linkages between density, layout, and outdoor thermal comfort remain inadequately characterized. This study investigates these correlations in the desert city of Biskra, Algeria. We conducted extensive in-situ measurement campaigns during peak summer and winter periods across six neighborhoods spanning low to high-rise density fabrics. We captured air temperature, humidity, and wind velocity to enable thermal comfort assessment via the Effective Temperature (ET) and Equivalent Temperature (TEK) stress indices. Index sensitivity to density metrics from 23–86% was explored through One-Variable-At-A-Time (OVAT) analysis. Results show marked summer comfort deterioration with rising density due to constrained ventilation. However, higher densities demonstrate superior winter warmth through wind blocking despite reduced sunlight exposure. Sharp nonlinear differences emerge between seasons. Precision density thresholds prove difficult to define conclusively given typological diversities. However, indicative ranges tied to hazards are identified, providing guidelines for informed climatic adaptation. This research delivers vital evidence to advance bioclimatic strategies for enhancing habitability amidst urban expansion across delicate hot deserts. [ABSTRACT FROM AUTHOR]

Despite quinoa (Chenopodium quinoa Willd.) gaining international popularity in the early 21st century for its nutritional benefits, there remains a critical need to optimize its cultivation practices in arid regions. Current research often overlooks the combined effects of supplemental irrigation and foliar treatments on quinoa’s yield and water efficiency, particularly under challenging environmental conditions like those in Borg El-Arab, Egypt. Field studies were conducted in Borg El-Arab, Alexandria, Egypt, during the winter seasons of 2021/2022 and 2022/2023 to determine the influence of supplemental irrigation (rainfed, 2000, and 4000 m3/hectare, respectively) and foliar spraying of sodium silicate (control, 200, and 400 ppm) on yield, yield components, seed quality, and water usage efficiency in quinoa cv. Chibaya grown in arid lands. Three replications were used in a split-plot design. The main plots were designated for irrigation, while the subplots were designated for foliar spraying. The results indicate that applying irrigation at a rate of 4000 m3/hectare significantly increased leaf dry weight per plant by 23.5%, stem dry weight per plant by 18.7%, total dry weight per 25 plants by 21.4%, leaf area per plant by 19.2%, and straw yield by 26.8% compared to the control treatment. There were no significant differences between irrigation with the rate of 4000 m3 or 2000 m3/hectare on biological yield kg/hectare, N (%), P (mg/100 g), and protein (%). The utilization of sodium silicate had no significance on all studied features except for straw yield kg ha−1 at the rate of 200 or 400 ppm. The results regarding the RAPD1 primer revealed that the 2000+0 silicon treatment was the only treatment that resemble the control with no up- or downregulated fragment. Moreover, 20 upregulated fragments were observed in all treatments, while 19 DNA fragments were downregulated. Furthermore, the results obtained regarding the RAPD2 primer revealed that 53 fragments were upregulated and 19 downregulated. Additionally, the RAPD3 primer demonstrated that 40 DNA fragments were upregulated, whereas 18 downregulated DNA fragments were detected. It may be inferred that the application of irrigation at a rate of 4000 m3 ha−1 might serve as a supplemental irrigation method. Spraying sodium silicate at a 400 mg L−1 concentration could alleviate the dry climate on the Egyptian shore.

The intensity, duration, and severity of drought increasing across the American Southwest. Plant restoration efforts are often thwarted by drought‐induced effects (i.e. drought‐induced mortality or failure to reproduce). Careful selection of plant materials to match future environmental conditions could improve restoration success under climate change. Here, we focus on Plantago patagonica, a priority arid land restoration species in the southwestern US. Using experimental drought in a greenhouse and supplemental watering in a common garden experiment, we quantified how the seed‐collection site environment influenced plant growth, performance, phenotypic plasticity, and evidence of local adaptation in 12 populations of P. patagonica. In the greenhouse, we found plants from hotter and drier environments had higher root:shoot ratios, while those from more variable precipitation regimes had greater total biomass in response to drought. Populations sourced from warmer environments exhibited sevenfold greater plasticity in root:shoot ratio compared to those from cooler environments, and there was strong evidence for local adaptation in phenology, as populations sourced from geographic locations nearer the common garden exhibited five times more flowering individuals than those sourced furthest from that garden. In the common garden, we found that plants sourced from wetter locations and those with more consistent precipitation regimes had lower mortality and higher specific leaf area, a proxy for growth, under unwatered ambient conditions. These results suggest plant performance of P. patagonica under reduced water availability is strongly shaped by the seed‐collection site environment and may be a useful tool for improving restoration outcomes in a changing world. [ABSTRACT FROM AUTHOR]

Urban flooding poses a significant problem in arid regions, where unusual rainfall events can lead to disastrous consequences. This study used geographic information systems (GIS) to identify and predict potential flood risk zones in Riyadh City, Saudi Arabia. A comprehensive flood risk map was created by integrating various datasets, including digital elevation models (DEM), lithology, precipitation patterns, slope, and drainage density. Through a weighted overlay analysis, Riyadh was segmented into zones with different levels of flood susceptibility, ranging from low to very high risk. The study area spans 905 km2. Of this total area, 32% is at a low risk of flooding, while 31%, 24%, and 12% of the area are at a moderate, high, and very high risk of flooding, respectively. The findings of the study were validated through field surveys conducted before and after recent rainfall events. These validation efforts corroborated the high-risk areas predicted by the model, thereby ensuring the reliability of the map for future urban planning and risk mitigation strategies. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore some physiological and productivity responses of two chili pepper morphotypes (Capsicum annum L.) exposed to different soil moisture contents. A randomized block design in a split-plot arrangement with four replicates was used. The large plots (32 m long and 3.2 m width) were 25% ± 2 as the optimum soil moisture content (OSMC), and 20% ± 2 as the suboptimum soil moisture content (SSMC); the small plots (16 m long and 3.2 m width) were two chili pepper morphotypes: Jalapeño and Chilaca, respectively. Jalapeño plants showed more stability in relative water content (RWC), photosynthetic activity (µmol CO2/m2/s), and a relatively low transpiration (mmol H2O/m2/s) and stomatal conductance (µmol H2O/m2/s); therefore, it had a higher number of flowers per plant and number of fruits per plant, consequently recording a high fruit production of 3.94 and 2.99 kg/m2 in OSMC and SSMC, respectively. In contrast, the Chilaca chili showed low stability in water relative content (WRC), photosynthesis, and transpiration, going from OSMC to SSMC, as well as showed a lower yield in SSMC; however, all of that was compensated by its size and weight of the fruit per plant, with a yield of 4.95 kg/m2 in OSMC. Therefore, the Jalapeño chili pepper could be an option when the irrigation water is limited, and the Chilaca chili pepper when this resource is not limited. [ABSTRACT FROM AUTHOR]

The accuracy, speed, and feasibility of studying soil properties depend largely on the techniques used and their efficiency to correlate soil attributes. This study aimed to investigate the capability of the diffuse reflectance spectroscopy (DRS) and magnetic susceptibility (MS) methods in predicting and mapping soil physicochemical properties and monitoring their spatial distribution in an arid and semi-arid region, southern Iran. A total of 100 surface soil samples were collected from the depth of 0–20 cm and analyzed for OC, CCE, gypsum, clay, EC, Fed, χlf, and VIS–NIR–SWIR (350–2500 nm) spectroscopy using standard laboratory methods. The DRS and MS techniques were then used to estimate soil properties using the partial least squares regression (PLSR) and the linear regression methods, respectively. Results showed an accurate estimation of gypsum (RPD = 2.3 and R2 = 0.81), and reliable estimations for clay, Fed, OC, CCE, and EC by the PLSR method. However, the MS method presented reliable results only for the Fed (RPD = 1.5, R2 = 0.55). The DRS- and MS-derived predictive maps showed different spatial distribution patterns from the interpolated maps which were derived based on the observed data. The Fed parameter showed the most similarity with its observed data in both DRS- and MS-derived maps; whereas in the case of other soil properties, the DRS method presented a better prediction performance compared to the MS one. The findings of the present study highlighted the significant capability of the DRS technique as an efficient predictor for soil properties in the studied area. [ABSTRACT FROM AUTHOR]

Background and aims -- Endemism may be defined according to the time of origin of taxa. Neo-endemics refer to relatively recent species that have not dispersed outside their ancestral areas. In contrast, paleo-endemics refer to species of ancient origins, which are currently geographically restricted but probably were more widespread in the past. Geographically, endemism areas may also be based on the co-occurrence of more than one species. We aimed to qualitatively identify the neo-endemism and paleo-endemism of endemic Cactaceae of the Tehuacán-Cuicatlán Valley, as well as to quantitatively assess paleo- and neo-endemics areas. Material and methods -- Using a dated molecular phylogeny of endemic Cactaceae, we defined paleo- and neo-endemics using an arbitrary boundary of 2.6 million years ago; we also assessed the significance of concentrations of these species using a categorical analysis of paleo- and neo-endemism. Key results -- Our results showed that most endemic Cactaceae in the Tehuacán-Cuicatlán Valley arose throughout the Pleistocene, while categorical analysis indicated localised mixed- and super-endemism (including both paleo- and neoendemics) areas. Conclusion -- We suggest that paleo- and neo-endemics, as well as localised mixed-endemism areas, may have originated due to a probable high climatic stability in the Tehuacán-Cuicatlán Valley, which in addition to topographically rugged and ecologically complex zones (e.g. ecotones, isolated habitat patches) may have allowed it to function as a refuge throughout Pleistocene climatic changes, mainly promoting the speciation of neo-endemics, as well as the persistence of relatively few paleo-endemics. [ABSTRACT FROM AUTHOR]

Sotol (Dasylirion leiophyllum) is a shrubby species that grows in the Chihuahuan Desert. Sotol plants are commonly used to produce an alcoholic beverage, also known as "sotol". A study was carried out to assess the composition and structure of shrubby communities where sotol inhabits in northern Mexico. The importance value index (IVI), diversity indexes, and structural attributes of the sotol community were estimated. Furthermore, a principal component and a cluster analysis were conducted in order to identify possible associations of species along the sotol distribution area. A total of 10,273 plants belonging to 17 families and 46 species were recorded, where the Agave lechuguilla and Tiquilia greggi were the most abundant species. Higher abundances of sotol and higher diversity indexes were observed in hillside areas and eastern aspects. The multivariate analyses revealed five shrubby groups in the distribution area of sotol, which grows in valleys, hillsides, and also on the top of mountains. The main communities found where sotol grows are rosetophyllous, microphyllous, and mesquite communities, and also, in higher altitudes, sotol is associated with oak species. This information is not only useful for a better species knowledge, but also for the protection of shrubby communities where Dasylirion leiophyllum inhabits. [ABSTRACT FROM AUTHOR]

Adaptation strategies to climate change (CC) that do not consider local perspectives tend to fail at specific sites. Searching for complementary actions, we aimed to assess how farmers’ perceptions about climatic hazards match past and future climate data. An original common coding was developed to combine qualitative and quantitative data using climate trend indicators. In our case study, we compared climate perceptions of family farmers from seven localities of northern Patagonia, Argentina, collected from seven participatory risk assessment workshops, with meteorological records from six local weather stations (1999–2020) and national projected CC scenarios (simulations to 2039). In the context of a semiarid region, people’s greatest concern was found to be focused on the scarcity of water resources. Despite this focus, results showed that temperature (T) had greater predictability from farmers than precipitation (P): perceptions were better associated with past and future T variable trends (T mean, T min, and T max), than with P ones (average rainfall and number of days with rainfall events > 10 mm). We discussed social and technical causes of matches or mismatches among the views. The information resulting from the comparison of perceived climatic hazards and climate data can be used to improve climate communication with farmers, to collectively assess, design, and prioritize site-specific adaptation measures and future actions. The detailed description of our methodology would allow others to take advantage of local and technical knowledge to overcome climate change challenges. [ABSTRACT FROM AUTHOR]

Climate change and increases in human activities are threatening water availability in the Arequipa Region (southern Peru). However, to date, there has not been a comprehensive inventory of surface water data or an investigation of current surface water conditions or forecasted future conditions resulting from increased anthropic demand or stresses from climate change. This study evaluates surface water resources management including storage, diversions, and conveyance in the Arequipa Region, while creating a tool for the evaluation of future scenarios in the five main watersheds of this arid region of southern Peru. State-of-the art, open-source modeling software was used. Water uses for each watershed were evaluated against predicted reservoir inflows and streamflows for different periods. In addition to the above, 12 climate change models and different shared socioeconomic pathways (SSP) were ensembled for the five watersheds. A semi-distributed approach and an innovative simulation splitting approach was used for each watershed, which allowed for different starting dates for the simulations using all available data obtained from different sources (government and private). Results indicate that the region is expected to have increased flows during the wet season and no significant changes during the dry season. Reservoir inflows are expected to increase up to 42 and 216% for the lowest and highest SSP evaluated, respectively. Similarly, the model projected streamflow increases up to 295 and 704%, respectively. Regarding yearly water availability and considering current and future demands for the watersheds under study, water deficits are not expected in the future if current reservoir storage can be maintained, though it is expected that reservoirs won't be able to store predicted higher flows, so important volumes of water could be lost during the wet season to the ocean by natural drainage. Given the uncertainty of climate change projections, if future water sustainability is desired, storage and irrigation efficiencies should be improved and reservoir sedimentation should be evaluated. [ABSTRACT FROM AUTHOR]

Modernist ontologies of water physically materialise in Phoenix’s landscape: over 100 miles of canals convey water to the suburban grid, where thousands of gallons are piped into backyard swimming pools. The canal and pool are thus joined in architectural folly to move, hold, and control water in the service of sustaining the belief that dry ecologies are but supply chain problems in need of engineering solutions. These typologies reveal longstanding entanglements between the promises of modernity and aridland urbanism; and they further amplify the immense challenge of transitioning away from modern water infrastructure in the face of climate change. By using the canal and the pool as signifiers of the insidious entanglements between modernity, growth, and aridland urbanism, this article advances an historical examination of Phoenix that destabilises tropes of water scarcity as a problem to be solved but which has also created cultural perceptions of abundant water.

Biological soil crusts are thin, inconspicuous communities along the soil atmosphere ecotone that, until recently, were unrecognized by ecologists and even more so by microbiologists. In its broadest meaning, the term biological soil crust (or biocrust) encompasses a variety of communities that develop on soil surfaces and are powered by photosynthetic primary producers other than higher plants: cyanobacteria, microalgae, and cryptogams like lichens and mosses. Arid land biocrusts are the most studied, but biocrusts also exist in other settings where plant development is constrained. The minimal requirement is that light impinge directly on the soil; this is impeded by the accumulation of plant litter where plants abound. Since scientists started paying attention, much has been learned about their microbial communities, their composition, ecological extent, and biogeochemical roles, about how they alter the physical behavior of soils, and even how they inform an understanding of early life on land. This has opened new avenues for ecological restoration and agriculture. [ABSTRACT FROM AUTHOR]

"Dry Matters" describes a dual interest. The phrase reminds designers that drylands are active contributors to our collective futures and advocates for an expanded material palette to design resilient arid landscapes. It is also the conceptual framework of a graduate design studio that I teach at the University of California, Berkeley which is predicated on the assumption that aridity is an intrinsically valuable ecological condition. In this essay, I recount how dryland policies, attitudes, and perceptions manifest materially through design and planning. Grounding this research, I show how engaging the history of place can be a pedagogical framework for students to design speculative dryland futures. [ABSTRACT FROM AUTHOR]

Wheat is one of the most important cereal crops in Egypt and all over the world. Its productivity is adversely affected by drought due to deficient irrigation to provide nutrients required for plant growth. In a field experiment, silicon foliar applications at concentrations of 0, 200, and 400 mg L−1 were performed at different irrigation rates ranging from 1000 to 4000 m3 ha−1 to assess water irrigation productivity and wheat crop yield in a calcareous soil under arid climate conditions. Increased irrigation rates led to a significant increase in soil nutrient dynamics, as well as in the number and weight of grains per spike, leaf area index, grain yield, straw yield, and biological yield, with the exception of the weight of 1000 grains. Spraying with sodium silicate had a significant impact on grain yield and harvest index but did not significantly impact the other traits. Furthermore, the interaction between irrigation and silicate application rates showed significance only for grain yield, the number of spikes/m2, and the harvest index. Applying three times irrigation could produce the highest nutrient retention, wheat yield, and water irrigation productivity. No significance was observed between 3000 m3 ha−1 and 4000 m3 ha−1 irrigation, indicating a saving of 25% of applied irrigation water. It can be concluded that applying irrigation at 3000 m3 ha−1 could be a supplemental irrigation strategy. High wheat grain yield can be achieved under deficit irrigation (3000 m3 ha−1) on the northwestern coast of Egypt with an arid climate by spraying crops with sodium silicate at a rate of 400 mg L−1.

Estimating soil erodible fraction based on basic soil properties in arid lands is a valuable research topic in the field of soil science and land management. The Proximal Sensing (PS) technique offers a non-destructive and efficient method to assess wind erosion potential in arid regions. By using Partial Least Squares Regression (PLSR) and Support Vector Machine (SVM) models and combining soil texture and chemical properties, determined through Visible-Near Infrared (vis-NIR) spectroscopy in 96 soil samples, this study aims to predict soil erodibility, soil organic matter (SOM), and calcium carbonate equivalent (CaCO3) in arid lands located in Elkobaneyya Valley, Aswan Governorate, Egypt. Results showed that the soil erodibility fraction (EF-Factor) had the highest values and possessed a strong relationship between slope and SOM of 0.01% in determining soil erodibility. The PLSR model performed better than SVM for estimating SOM, CaCO3, and EF-Factor. Furthermore, the results showed that the spectral responses of CaCO3 were observed in separate places in the wavelengths of 570, 649, 802, 1161, 1421, 1854, and 2362 nm, and the wavelengths with SOM parameter were 496, 658, 779, 1089, 1417, 1871, and 2423 nm. The EF-factor shows the highest significant correlation with spectral reflectance values at 526, 688, 744, 1418, 1442, 2292, and 2374 nm. The accuracy and performance of the PLSR model in estimating the EF-Factor using spectral reflectance data and the distribution of data points for both the calibration and validation data-sets indicate a good accuracy of the PLSR model, with RMSE values of 0.0921 and 0.0836 Mg h MJ−1 mm−1, coefficient of determination (R2) values of 0.931 and 0.76, and RPD values of 2.168 and 2.147, respectively.

Rapid urbanization across hot arid environments transforms local microclimates, yet linkages between density, layout, and outdoor thermal comfort remain inadequately characterized. This study investigates these correlations in the desert city of Biskra, Algeria. We conducted extensive in-situ measurement campaigns during peak summer and winter periods across six neighborhoods spanning low to high-rise density fabrics. We captured air temperature, humidity, and wind velocity to enable thermal comfort assessment via the Effective Temperature (ET) and Equivalent Temperature (TEK) stress indices. Index sensitivity to density metrics from 23–86% was explored through One-Variable-At-A-Time (OVAT) analysis. Results show marked summer comfort deterioration with rising density due to constrained ventilation. However, higher densities demonstrate superior winter warmth through wind blocking despite reduced sunlight exposure. Sharp nonlinear differences emerge between seasons. Precision density thresholds prove difficult to define conclusively given typological diversities. However, indicative ranges tied to hazards are identified, providing guidelines for informed climatic adaptation. This research delivers vital evidence to advance bioclimatic strategies for enhancing habitability amidst urban expansion across delicate hot deserts.

Mammals have been widely recognized as mobile link species that can vectorize resources across the landscape. In this study, we analyze the biodeposition of waste products egested by native herbivorous mammals of the Monte Desert to document for the first time the implications of the restoration of a native forest on this process. We compared a restored native woodland an adjacent grazing field in terms of the spatial distribution of waste products, the biodiversity of trophic items stored in fecal pellets, and the C:N ratio as a predictor of nutrients supplied to the soil. We found that fecal pellets of mammal species were intermingled and spatially distributed throughout the entire landscape, but they were more abundant in the restoration area, indicating the influence of land management types on the distribution process. The two mammal species presented different feeding strategies; however, the plant species consumed in the grazing field indicate decreased food options for native mammals, meaning a smaller amplitude of their trophic niches under this land management. The low C:N ratio and the high nitrogen pool provided by the pellets in the restoration area suggest a potential benefit to plant communities. However, the higher organic C jointly with the lower C:N ratio observed in fecal pellets of grazing field indicate a low decomposability which could promote the conservation of C in the soil. [ABSTRACT FROM AUTHOR]

A temporal trend analysis of weather variables is needed for developing mitigation and adaptation strategies to climate change. The objective of this work was to study temporal trends of 17 extreme temperature indices in North-Central Mexico (NCM). We used daily observations of maximum and minimum temperatures from 127 weather stations for 34 years (1980–2013). The extreme temperature indices were calculated with the RClimDex v1.9 package. Analysis of trend indices was carried out with the Mann–Kendall technique and the rate of change with the Theil–Sen estimator. Except for the growing season length, all-temperature indices showed statistically significant positive trends (SSPT) (p≤0.05$p\leq\nobreak 0.05$) between 1 and 62; except for the cold spell duration indicator, all indices showed statistically significant negative trends (SSNT) between 3 and 62. The SSPT of all indices varied between 0.246 °C decade−1 (TMINMEAN) and 48 days decade−1 (SU25), while the SSNT varied between −55.238 days decade−1 (SU25) and −0.181 °C decade−1 (TMINMEAN). In NCM, the increase in some indices could be causing an increase in crop water requirements and poorly meeting some crop's chilling requirements. In crops, such as grapevine, peach, and apple, an excellent short-term strategy to adapt to the decrease in cold winter and to compensate for the satisfaction of poor chilling hours using biostimulant of sprouting should be considered. New varieties/hybrids of corn and beans for dealing with the increase in warm days (TX90p), summer days (SU25), warm nights (TN90p), and tropical nights must be available; also, these new varieties should have shorter cycle and should be cold resistant. The results of this work constitute a reliable tool for generating answers for measures of adaptation to the onslaught of climate change in NCM.

Drylands correspond to ca. 40% of the world's land surface. Because of their ecological importance, these areas are regularly considered for agricultural purposes. Scorpion assemblages often exhibit higher levels of species diversity in dry habitats and are beneficial indicators in ecological studies in such environments. In this study, we investigated the effects of climatic and spatial predictors on beta diversity patterns among scorpion assemblages distributed in the drylands of Egypt. Scorpion occurrences were compiled from the scientific literature. For each location, we created a set of climatic variables related to precipitation, temperature, and solar irradiation, as well as spatial predictors. A total of 134 scorpion occurrences were obtained, comprising 21 species grouped into three families. Climatic and spatial variables together influenced the patterns of scorpion diversity in Egyptian landscapes. Species replacement accounted for 69% of the total beta diversity. In addition, species replacement was positively affected by climatic and spatial variables. Our results suggest a reciprocal link between the region's ecological history and the patterns of beta diversity observed in scorpion assemblages from Egyptian drylands. [ABSTRACT FROM AUTHOR]

Biomonitoring is vital for establishing baseline data that is needed to identify and quantify ecological change and to inform management and conservation activities. However, biomonitoring and biodiversity assessment in arid environments, which are predicted to cover 56% of the Earth's land surface by 2100, can be prohibitively time consuming, expensive, and logistically challenging due to their often remote and inhospitable nature. Sampling of environmental DNA (eDNA) coupled with high‐throughput sequencing is an emerging biodiversity assessment method. Here we explore the application of eDNA metabarcoding and various sampling approaches to estimate vertebrate richness and assemblage at human‐constructed and natural water sources in a semi‐arid region of Western Australia. Three sampling methods: sediment samples, filtering through a membrane with a pump, and membrane sweeping in the water body, were compared using two eDNA metabarcoding assays, 12S‐V5 and 16smam, for 120 eDNA samples collected from four gnammas (gnamma: Australian Indigenous Noongar language term–granite rock pools) and four cattle troughs in the Great Western Woodlands, Western Australia. We detected higher vertebrate richness in samples from cattle troughs and found differences between assemblages detected in gnammas (more birds and amphibians) and cattle troughs (more mammals, including feral taxa). Total vertebrate richness was not different between swept and filtered samples, but all sampling methods yielded different assemblages. Our findings indicate that eDNA surveys in arid lands will benefit from collecting multiple samples at multiple water sources to avoid underestimating vertebrate richness. The high concentration of eDNA in small, isolated water bodies permits the use of sweep sampling that simplifies sample collection, processing, and storage, particularly when assessing vertebrate biodiversity across large spatial scales. [ABSTRACT FROM AUTHOR]

Simple Summary: Cacti account for nearly 1440 species, most of them native to the American continent. These succulent plants are the most ubiquitous elements of the arid ecosystems. Mexico harbors the highest number of cacti species in the world (45%). Unfortunately, many of them are threatened by human activities. Although having this biodiversity relevance, presently the evolutionary processes of cacti have been poorly studied. Because the biological and conservation unit is the species, evolutionary studies provide relevant information. In this study, we analyzed how and when past events shaped the evolutionary relationships of 103 species. Our results showed that from 4.5 million years ago the arid regions of Mexico were the locations for abundant cacti speciation. From these lands, cacti have colonized most of the Mexican territories, the southern regions of the United States, as well as the Caribbean. The evolution of these plants was probably promoted by past temperatures that were comparable to the present ones. We identified different speciation and dispersal events in these fascinating plants. This study identified the Mexican Plateau as the place where the early stages of the evolutionary history of cacti occurred. Mexico harbors ~45% of world's cacti species richness. Their biogeography and phylogenomics were integrated to elucidate the evolutionary history of the genera Coryphantha, Escobaria, Mammillaria, Mammilloydia, Neolloydia, Ortegocactus, and Pelecyphora (Mammilloid Clade). We analyzed 52 orthologous loci from 142 complete genomes of chloroplast (103 taxa) to generate a cladogram and a chronogram; in the latter, the ancestral distribution was reconstructed with the Dispersal-Extinction-Cladogenesis model. The ancestor of these genera arose ~7 Mya on the Mexican Plateau, from which nine evolutionary lineages evolved. This region was the site of 52% of all the biogeographical processes. The lineages 2, 3 and 6 were responsible for the colonization of the arid southern territories. In the last 4 Mya, the Baja California Peninsula has been a region of prolific evolution, particularly for lineages 8 and 9. Dispersal was the most frequent process and vicariance had relevance in the isolation of cacti distributed in the south of Mexico. The 70 taxa sampled as Mammillaria were distributed in six distinct lineages; one of these presumably corresponded to this genus, which likely had its center of origin in the southern part of the Mexican Plateau. We recommend detailed studies to further determine the taxonomic circumscription of the seven genera. [ABSTRACT FROM AUTHOR]

Blue Diamond cholla (Cylindropuntia multigeniculata (Clokey) Blackb. [Cactaceae]) is a rare cactus of the Mojave Desert. We explored whether cultivation from joint cuttings is a viable method for supporting threatened populations. Terminal joints were collected from adult plants at the type locality and grown in a shade house: We tested whether 2 soil mixes that varied in the ratio of inorganic and organic components (50:50 compared to 85:15) and 2 watering frequencies (250 ml every 5 d compared to 500 ml every 10 d) promote root growth important to outplanting survival. Plants grown from joint cuttings in the 50:50 soil had greater shoot and root biomass, produced more joint segments, and had higher initial and final survivorship over the 5-mo study. Neither soil nor watering treatments shifted biomass allocation to roots as hypothesized, but frequent watering produced longer roots, which may benefit reintroduced plants by assisting root access to deep soil moisture. Despite their vigor during collection, freshly cut joints rapidly declined in condition, resulting in approximately 50% mortality during the first month of the study. Initial mortality was not explained by the identity, condition, or size of the maternal plant. Prior-year weather patterns and collection procedures may influence quality and durability of joint cuttings and require further study. While larger plants were produced from the 50:50 mix, and root length was increased by frequent watering, reintroduction of nursery-grown plants will indicate whether such treatments aid establishment in the dry habitat where this species occurs. [ABSTRACT FROM AUTHOR]

Clonal species Agave fourcroydes and A. sisalana from ancient crops have become invasive in Mediterranean drylands, posing a severe threat to ecologically valuable native plant communities. However, we barely know the relative contribution of clonal mechanisms underlying their invasive behaviour. Therefore, environmental managers must face this problem without scientific evidence on the most effective methods to eradicate or control these invasions. In this study, we monitored populations of A. fourcroydes and A. sisalana and carried out field and experimental plantings (in situ and under controlled environmental conditions) to assess the efficacy of three clonal mechanisms: shoots from rhizomes, shoots from rosettes, and aerial bulbils from floral scapes). Both species showed very similar performance in their clonal expansion. Shoot production from rhizomes was the primary mechanism for densifying Agave populations, emerging to the soil 1.5 ± 2.1 shoots per individual. Moreover, we did not observe mortality of new shoots from rhizomes. These new clonal individuals seemed to ensure their survival by connecting to the mother plant (clonal integration). In addition, contractile roots, only recorded in shoots from rhizomes, could represent an advantage allowing them to react to harsh environmental conditions. Regarding shoots from rosettes, individuals produced 0.63 ± 1.01 shoots on average, with no mortality recorded, but without guaranteeing the replacement of mother plants. Finally, bulbil production and their rooting under controlled and favourable conditions were very high, although their establishment success under arid conditions proved irrelevant. These results suggest that management actions should focus on the removal of shoots from rhizomes. This approach could be an efficient, feasible, and cost-effective medium- to long-term habitat management strategy to control these Agave invasions, with widespread application worldwide in similar invasion processes. [ABSTRACT FROM AUTHOR]

Urban flooding poses a significant problem in arid regions, where unusual rainfall events can lead to disastrous consequences. This study used geographic information systems (GIS) to identify and predict potential flood risk zones in Riyadh City, Saudi Arabia. A comprehensive flood risk map was created by integrating various datasets, including digital elevation models (DEM), lithology, precipitation patterns, slope, and drainage density. Through a weighted overlay analysis, Riyadh was segmented into zones with different levels of flood susceptibility, ranging from low to very high risk. The study area spans 905 km2. Of this total area, 32% is at a low risk of flooding, while 31%, 24%, and 12% of the area are at a moderate, high, and very high risk of flooding, respectively. The findings of the study were validated through field surveys conducted before and after recent rainfall events. These validation efforts corroborated the high-risk areas predicted by the model, thereby ensuring the reliability of the map for future urban planning and risk mitigation strategies.