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Soil desertification poses a critical ecological challenge in arid and semiarid climates worldwide, leading to decreased soil productivity due to the disruption of essential microbial community processes. Fungi, as one of the most important soil microbial communities, play a crucial role in enhancing nutrient and water uptake by plants through mycorrhizal associations. However, the impact of overgrazing-induced desertification on fungal community structure, particularly in the Caatinga biome of semiarid regions, remains unclear. In this study, we assessed the changes in both the total fungal community and the arbuscular mycorrhizal fungal community (AMF) across 1. Natural vegetation (native), 2. Grazing exclusion (20 years) (restored), and 3. affected by overgrazing-induced degradation (degraded) scenarios. Our assessment, conducted during both the dry and rainy seasons in Irauçuba, Ceará, utilized Internal Transcribed Spacer (ITS) gene sequencing via Illumina® platform. Our findings highlighted the significant roles of the AMF families Glomeraceae (∼71% of the total sequences) and Acaulosporaceae (∼14% of the total sequences) as potential key taxa in mitigating climate change within dryland areas. Moreover, we identified the orders Pleosporales (∼35% of the total sequences) and Capnodiales (∼21% of the total sequences) as the most abundant soil fungal communities in the Caatinga biome. The structure of the total fungal community differed when comparing native and restored areas to degraded areas. Total fungal communities from native and restored areas clustered together, suggesting that grazing exclusion has the potential to improve soil properties and recover fungal community structure amid global climate change challenges.

This paper presents a comprehensive investigation into the performance of grid-connected photovoltaic (PV) power plants situated in a hot desert climate. The study employs a combination of simulation models and experimental data to assess the impact of two tracking systems – fixed and dual-axis – on the overall efficiency and energy yield of the PV installations. Through detailed simulations, we analyze the dynamic behavior of the PV systems under varying solar irradiance and the atmospheric conditions typical of hot desert environments. The dual-axis tracking system is compared against the conventional fixed-mount system to evaluate its effectiveness in maximizing energy production and improving the overall efficiency of the PV power plants. Experimental data collected from an actual grid-connected PV facility in a hot desert region is incorporated to validate the simulation results and enhance the accuracy of the study. The observed performance metrics include energy output, system reliability, and the impact of environmental factors on long-term sustainability. In general, in all weather conditions, solar tracking provides better yields than a fixed solar module, generating about 32% and 12% more energy in sunny and overcast weather conditions, respectively. Under sunny weather, the two-axis sun tracking system and a fixed tilt angle produce 333.228 kWh and 247.56 kWh of energy, respectively. The energy yield generated on a partly cloudy day by a two-axis sun tracking system and a fixed tilt angle PV system is 281.496 kWh and 257.856 kWh, respectively. In addition, the highest electricity gain for two-axis solar trackers versus fixed PV plants was found to be 34.6%, and the lowest value was found to be 9.16%. The experimental analysis shows that the efficiency of the polycrystalline PV module is 12% and 14% on sunny days and cloudy days, respectively. The comparison between fixed and dual-axis tracking systems contributes to the optimization of PV installations, enabling more informed decisions for sustainable energy production in regions characterized by high temperatures and intense solar radiation. To support the expanding applications of grid-tied PV systems with a sun tracker in the same or comparable location and climate conditions (Saharan environment), these studies have the practical utility of advising and offering helpful feedback to engineers, system designers, contractors, and investors. [ABSTRACT FROM AUTHOR]

Green vegetation may protect against heat-related death by improving thermal comfort. Few studies have investigated associations of green vegetation with heat-related mortality in Latin America or whether associations are modified by the spatial configuration of green vegetation. We used data from 323 Latin American cities and meta-regression models to estimate associations between city-level greenness, quantified using population-weighted normalized difference vegetation index values and modeled as three-level categorical terms, and excess deaths from heat (heat excess death fractions [heat EDFs]). Models were adjusted for city-level fine particulate matter concentration (PM2.5), social environment, and country group. In addition to estimating overall associations, we derived estimates of association stratified by green space clustering by including an interaction term between a green space clustering measure (dichotomized at the median of the distribution) and the three-level greenness variable. We stratified analyses by climate zone (arid vs. temperate and tropical combined). Among the 79 arid climate zone cities, those with moderate and high greenness levels had modestly lower heat EDFs compared to cities with the lowest greenness, although protective associations were more substantial in cities with moderate versus high greenness levels and confidence intervals (CI) crossed the null (Beta: -0.41, 95% CI: -1.06, 0.25; Beta -0.23, 95% CI: -0.95, 0.49, respectively). In 244 non-arid climate zone cities, associations were approximately null. We did not observe evidence of effect modification by green space clustering. Our results suggest that greenness may offer modest protection against heat-related mortality in arid climate zone Latin American cities.

Desert regions have emerged as ideal places for GW utility‐scale photovoltaic (PV) module installations because of their ultra‐large spaces, abundance of high‐irradiance sunshine hours, and clear sky. However, the harsh desert climate presents challenges to the reliability and bankability of PV modules. This review provides an in‐depth understanding of the unique desert parameters impact, desert‐induced degradation modes, status, and required properties of the bill of materials (BOMs) and suggestions for the development of desert standards. The review reveals that the climatic conditions in the desert are considerably harsher than those in the moderate climate. The main degradation mechanisms caused by the desert are ultraviolet (UV)‐induced discoloration, thermomechanical flaws of interconnects, and glass abrasion (because of soiling). The development of desert modules may necessitate the use of new‐generation modules with low‐temperature coefficients, high efficiency, high bifaciality, stability under UV light, and elevated temperatures. For the desert module application, options include advanced back sheets and encapsulants that are thermally and UV stable, free of acetic acid groups, and have a low water vapor transfer rate. The degradation modes induced by desert climate are not sufficiently addressed by the present environmental and safety standards through accelerated aging tests. As a result, this article provides a summary of current standards and recommends creating a new testing proposal called the "Hot Desert Test Cycle (HDTC)" sequence that is specific to the desert climate. This comprehensive review catalyzes the PV community to explore novel designs and develop desert PV modules while adhering to localized standards. [ABSTRACT FROM AUTHOR]

Elucidating the evolutionary process of animal adaptation to deserts is key to understanding adaptive responses to climate change. Here we generated 82 individual whole genomes of four fox species (genus Vulpes) inhabiting the Sahara Desert at different evolutionary times. We show that adaptation of new colonizing species to a hot arid environment has probably been facilitated by introgression and trans-species polymorphisms shared with older desert resident species, including a putatively adaptive 25 Mb genomic region. Scans for signatures of selection implicated genes affecting temperature perception, non-renal water loss and heat production in the recent adaptation of North African red foxes (Vulpes vulpes), after divergence from Eurasian populations approximately 78 thousand years ago. In the extreme desert specialists, Rueppell's fox (V. rueppellii) and fennec (V. zerda), we identified repeated signatures of selection in genes affecting renal water homeostasis supported by gene expression and physiological differences. Our study provides insights into the mechanisms and genetic underpinnings of a natural experiment of repeated adaptation to extreme conditions.

Understanding the processes that enable organisms to shift into more arid environments as they emerge is critical for gauging resilience to climate change, yet these forces remain poorly known. In a comprehensive clade-based study, we investigate recent shifts into North American deserts in the rock daisies (tribe Perityleae), a diverse tribe of desert sunflowers (Compositae). We sample rock daisies across two separate contact zones between tropical deciduous forest and desert biomes in western North America and infer a time-calibrated phylogeny based on target capture sequence data. We infer biome shifts using Bayesian inference with paleobiome-informed models and find evidence for seven independent shifts into desert habitats since the onset of aridification in the late Miocene. The earliest shift occurred out of tropical deciduous forests and led to an extensive radiation throughout North American deserts that accounts for the majority of extant desert rock daisies. Estimates of life history and micro-habitat in the rock daisies reveal a correlation between a suffrutescent perennial life history and edaphic endemism onto rocky outcrops, an ecological specialization that evolved prior to establishment and diversification in deserts. That the insular radiation of desert rock daisies stemmed from ancestors preadapted for dry conditions as edaphic endemics in otherwise densely vegetated tropical deciduous forests in northwest Mexico underscores the crucial role of exaptation and dispersal for shifts into arid environments.

Algeria is a country that has witnessed rapid development as a result of its abundant oil supplies. The country's GDP to energy consumption ratio clearly shows the need to adopt energy efficiency policies. Taking into account the regulation of excess solar radiation in the desert environment, this study examines the relationship between the shape of different buildings and their energy use. This research was divided into two stages. In the first stage, the ideal building shape for the city of Adrar, in terms of energy consumption, was determined by studying three basic geometric shapes, including square, rectangular, and triangle shapes. According to simulation research conducted using Design Builder (version 6.1.0), a square building was the best shape to maximize energy performance. To analyze the thermal behavior of different building shapes, all structures with expanded shapes were simulated based on the ideal shape discovered in the first stage. Of the three extended alternative cases, the case of the Mini Arrival offers the best energy efficiency and sufficient natural lighting thanks to its 90 cm depth and no vertical offset from the top of the window. By adding design principles to the design process, this study helps improve the energy efficiency of new buildings and also gives another angle on research methods for solving energy performance issues regarding desert buildings. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine effects of parity (primiparous vs. multiparous), seasonal heat stress at calving (summer vs. winter), and time postpartum on some parameters associated with colostrum quality in Holstein cows reared in the Sonoran Desert ecosystem. Forty-seven cows (11 primiparous and 36 multiparous) expected to calve during summer, and 46 cows during winter (14 primiparous and 32 multiparous) were randomly selected. Management and feeding before and after parturition were similar for cows in both seasons. After parturition, colostrum from all cows was evaluated for volume, weight, temperature, density, and content of fat, protein, solids non-fat (SNF), and immunoglobulins (IGG). Data were analyzed with a model that included effects of parity status, calving season, and time postpartum, as well as all interactions. Colostrum produced in summer was warmer (P < 0.01) by almost 6 °C than winter colostrum, while colostrum from multiparous was warmer (P = 0.02) by 1.2 °C than that produced by primiparous cows. Colostrum volume and weight were not impacted by parity, calving season or time postpartum. Density, protein, and SNF content in colostrum were higher (P < 0.01) in multiparous vs. primiparous cows, as well as at parturition (0 h postpartum) than at 12 h postpartum (P < 0.01). At calving (0 h), spring colostrum had higher fat content (P < 0.01) and lower (P < 0.01) IGG concentration than that collected in summer, and no difference (P > 0.05) between seasons was observed for these components at 12 h postpartum. Multiparous cows produced colostrum with higher (P < 0.01) IGG concentrations than primiparous cows. In conclusion, only 0-h colostrum and that from multiparous cows was categorized as "Excellent," meanwhile the colostrum produced under summer heat stress was characterized as "Good" with reduced fat content. While the lacteal secretion collected at 12 post-partum still classified as colostrum, substantially lower contents of IGG, protein, fat, and SNF decreased its classification to "Poor" from the classification of "Excellent" at 0 h postpartum. [ABSTRACT FROM AUTHOR]

Ectotherm predators and their prey could potentially respond differently to habitat temperatures. Predators might select higher temperatures to increase their probability of capture while prey could select lower or higher temperatures that may enhance their escape capability. We used a combination of field and laboratory analyses to characterise the thermal niches of predator species and their potential arthropod prey. We studied a predator–prey system in northern Chile using a common desert‐dwelling spider Loxosceles laeta and three potential prey: a tenebrionid beetle Psammetichus costatus (Coleoptera), Pycnoscelus surinamensis (Blattodea) and Porcellio laevis (Isopoda). Results showed that the predator L. laeta selects warmer temperatures (Tp = 27.22 ± 4.87°C) in laboratory and lower temperatures in field conditions (Ts = 20.8 ± 1.59°C), with low temperatures in the morning and high temperatures at night. The three prey species had lower and different preferred temperatures than the predator in laboratory conditions. However, we found a high overlap in the thermal niche between the predator and their prey in field conditions, whereby the predator selected similar temperatures to its prey, one exception being P. laevis that chooses completely different habitat temperatures. This suggests that predators look for their prey in places with low temperatures that are not thermally suitable for them, whereas the prey may use this strategy of selecting low temperatures to evade potential predators. [ABSTRACT FROM AUTHOR]

Rock-dwelling fungi play critical ecological roles in drylands, including soil formation and nutrient cycling; however, we know very little about the identity, function and environmental preferences of these important organisms, and the mere existence of a consistent rock mycobiome across diverse arid regions of the planet remains undetermined. To address this knowledge gap, we conducted a meta-analysis of rock fungi and spatially associated soil communities, surveyed across 28 unique sites spanning four major biogeographic regions (North America, Arctic, Maritime and Continental Antarctica) including contrasting climates, from cold and hot deserts to semiarid drylands. We show that rocks support a consistent and unique mycobiome that was different from that found in surrounding soils. Lichenized fungi from class Lecanoromycetes were consistently indicative of rocks across contrasting regions, together with ascomycetous representatives of black fungi in Arthoniomycetes, Dothideomycetes and Eurotiomycetes. In addition, compared with soil, rocks had a lower proportion of saprobes and plant symbiotic fungi. The main drivers structuring rock fungi distribution were spatial distance and, to a larger extent, climatic factors regulating moisture and temperature (i.e. mean annual temperature and mean annual precipitation), suggesting that these paramount and unique communities might be particularly sensitive to increases in temperature and desertification.

Political and economic initiatives intended to increase energy production while reducing carbon emissions are driving demand for solar energy. Consequently, desert regions are now targeted for development of large-scale photovoltaic solar energy facilities. Where vegetation communities are left intact or restored within facilities, ground-mounted infrastructure may have negative impacts on desert-adapted plants because it creates novel rainfall runoff and shade conditions. We used experimental solar arrays in the Mojave Desert to test how these altered conditions affect population dynamics for a closely related pair of native annual plants: rare Eriophyllum mohavense and common E. wallacei. We estimated aboveground demographic rates (seedling emergence, survivorship, and fecundity) over 7 yr and used seed bank survival rates from a concurrent study to build matrix models of population growth in three experimental microhabitats. In drier years, shade tended to reduce survival of the common species, but increase survival of the rare species. In a wet year, runoff from panels tended to increase seed output for both species. Population growth projections from microhabitat-specific matrix models showed stronger effects of microhabitat under wetter conditions, and relatively little effect under dry conditions (lack of rainfall was an overwhelming constraint). Performance patterns across microhabitats in the wettest year differed between rare and common species. Projected growth of E. mohavense was substantially reduced in shade, mediated by negative effects on aboveground demographic rates. Hence, the rare species were more susceptible to negative effects of panel infrastructure in wet years that are critical to seed bank replenishment. Our results suggest that altered shade and water runoff regimes associated with energy infrastructure will have differential effects on demographic transitions across annual species and drive population-level processes that determine local abundance, resilience, and persistence.

The Turpan basin is one of the most arid and water-insecure regions in China. Turpan Basin has a continental desert climate as it is located in central Eurasia and surrounded by mountains on all sides, with the lowest elevation of 154.5 m below sea level. Its rivers and water availability are mainly supplied by mountain snowmelt through surface streams and the Karez system. To assess the impact of climate change on streamflow in the Turpan basin, this study examined the long-term trends and change points of hydro-meteorological variables and explored the plausible correlation between them at annual and seasonal scales. A set of non-parametric statistical tests was applied to analyze the trend, its magnitude, and the change point of the hydro-meteorological variables from 1959 to 2012 in the Turpan basin. Results showed that the annual mean temperature had a significant increasing trend with an average warming rate of 0.26 °C/decade. Annual precipitation did not show a consistent upward or downward trend across the basin; however, there was a significant increase in winter precipitation. The increasing rates of streamflow at Alagou and Meiyaogou hydrological stations were the highest in the summer (0.42 and 0.18 m3/s per decade, respectively), which might increase the risk of flooding. The change points of various meteorological variables and streamflow can be generally found in the 1980s, in which temperature, precipitation, relative humidity, and streamflow had abrupt changes concurrently in 1986 and had respectively increased by 7.2, 41.3, 5.7, and 18.3% after 1986. In general, the strength of the relationship between annual streamflow and precipitation (0.34) was greater than that between streamflow and temperature (0.16). The significant increase in temperature and agriculture in the basin in recent decades indicates the importance of reducing unnecessary soil evaporation in agriculture to preserve water resources under climate change and using innovative technology to preserve soil quality under increasing evapotranspiration and irrigation. This study provided valuable information for understanding the changing properties of the streamflow in the basin and insights for better-integrated water resources management planning that focuses on mitigating flood disasters and soil degradation and improving irrigation efficiency. [ABSTRACT FROM AUTHOR]

In an era of rapid climate change and expansion of desertification, the extremely harsh conditions of drylands are a true challenge for microbial life. Under drought conditions, where most life forms cannot survive, rocks represent the main refuge for life. Indeed, the endolithic habitat provides thermal buffering, physical stability, and protection against incident ultraviolet (UV) radiation and solar radiation and, to some extent, ensures water retention to microorganisms. The study of these highly specialized extreme-tolerant and extremophiles may provide tools for understanding microbial interactions and processes that allow them to keep their metabolic machinery active under conditions of dryness and oligotrophy that are typically incompatible with active life, up to the dry limits for life. Despite lithobiontic communities being studied all over the world, a comprehensive understanding of their ecology, evolution, and adaptation is still nascent. Herein, we survey the fungal component of these microbial ecosystems. We first provide an overview of the main defined groups (i.e., lichen-forming fungi, black fungi, and yeasts) of the most known and studied Antarctic endolithic communities that are almost the only life forms ensuring ecosystem functionality in the ice-free areas of the continent. For each group, we discuss their main traits and their diversity. Then, we focus on the fungal taxonomy and ecology of other worldwide endolithic communities. Finally, we highlight the utmost importance of a global rock survey in order to have a comprehensive view of the diversity, distribution, and functionality of these fungi in drylands, to obtain tools in desert area management, and as early alarm systems to climate change.

Natural selection is an important driver of genetic and phenotypic differentiation between species. For species in which potential gene flow is high but realized gene flow is low, adaptation via natural selection may be a particularly important force maintaining species. For a recent radiation of New World desert shrubs (Encelia: Asteraceae), we use fine-scale geographic sampling and population genomics to determine patterns of gene flow across two hybrid zones formed between two independent pairs of species with parapatric distributions. After finding evidence for extremely strong selection at both hybrid zones, we use a combination of field experiments, high-resolution imaging, and physiological measurements to determine the ecological basis for selection at one of the hybrid zones. Our results identify multiple ecological mechanisms of selection (drought, salinity, herbivory, and burial) that together are sufficient to maintain species boundaries despite high rates of hybridization. Given that multiple pairs of Encelia species hybridize at ecologically divergent parapatric boundaries, such mechanisms may maintain species boundaries throughout Encelia.

In this paper, a 2.25 kWp grid integrated with the tied solar park has been implanted in the Renewable Energy Applied Research Unit (URAER) in a dry and harsh desert region. The PV plant uses micromorph thin-film solar modules (a-Si/μc-Si) technology. The photovoltaic module systems (PVS) were evaluated from May 2015 to December 2020 (around five and a half years of operation), and the electricity was injected into the internal network of the low-voltage power supply. Performance evolution has been conducted in this work as stated by the IEC61724 guideline. The monthly and annual performance indicators analyzed and assessed consist of reference yield, array yield, final yield, system losses, capture losses, PV module efficiency, system efficiency, inverter efficiency, capacity factor, and performance ratio. The annual electricity production is 3688.28 kWh, 3188.25 kWh, 3306.28 kWh, 3136.05 kWh, and 2952.81 kWh for 2016, 2017, 2018, 2019, and 2020 operating periods, respectively. The solar park's total produced energy yield over the monitored period and the quantity of CO 2 emissions avoided are 16,271.67 kWh and 14.17 tons, respectively, which can significantly contribute to and help in purifying the environment from pollution. In addition, the energy results produced by the PVS were compared to those found by the four widely used PV simulation tools (PVsys, PVGIS, NREL's PVWatts® Calculator and Solar Med-Atlas). Furthermore, this work investigates and quantifies the degradation phenomenon of solar PVS power output after five years and a half years of outdoor exposure. There is around 0.22 % degradation per year. When this rate was compared to other studies conducted worldwide, it was shown to be highly appropriate. Technical-economic research was also conducted, revealing that the system's PVS period, which establishes its sustainability, is between 9 and 12 years. The results demonstrate that micromorph thin-film modules perform better and are more efficient under harsh real-world outdoor environmental conditions. Inventux modules preserve most of their better performance even with increasing module temperature. This kind of PV module technology is low-insensitive to the highest PV module temperature. Compared to the literature, micromorph thin-film technologies are better and preferable than crystalline modules under desert environmental conditions. The results also indicate that grid-connected solar park plants using this kind of technology are feasible in the hot arid climate to produce electricity and may participate in future energy projects in the country. • This study investigates the performance of a pilot grid-tied solar power station located in the southern region of Algeria, which has been operating in the harsh desert climate. • Data recorded between May 2015 and December 2020 was used to evaluate the system's performance, and the results were compared to those obtained from four simulation tools. • The study found that the micromorph thin-film module technology from Inventux Company was the most reliable and potent option for this site, with better performance and resistance to changes in temperature. • The system's annual electricity production and CO 2 emissions were recorded for five operating periods, and degradation in solar PV power output after six years of outdoor exposure was quantified, with a degradation rate of 1.10%/year. • Technical-economic research indicated that the system had a payback period of 9-12 years, making it a feasible option. • The findings will provide useful guidelines for decision-makers, engineers, and industrial companies interested in large-scale solar photovoltaic systems in hot, harsh semi-arid climates. [ABSTRACT FROM AUTHOR]

Temperature is known to influence many aspects of organisms and is frequently linked to geographical species distributions. Despite the importance of a broad understanding of an animal's thermal biology, few studies incorporate more than one metric of thermal biology. Here we examined an elevational assemblage of Habronattus jumping spiders to measure different aspects of their thermal biology including thermal limits (CTmin, CTmax), thermal preference, V̇CO2 as proxy for metabolic rate, locomotor behavior and warming tolerance. We used these data to test whether thermal biology helped explain how species were distributed across elevation. Habronattus had high CTmax values, which did not differ among species across the elevational gradient. The highest-elevation species had a lower CTmin than any other species. All species had a strong thermal preference around 37 °C. With respect to performance, one of the middle elevation species was significantly less temperature-sensitive in metabolic rate. Differences between species with respect to locomotion (jump distance) were likely driven by differences in mass, with no differences in thermal performance across elevation. We suggest that Habronattus distributions follow Brett's rule, a rule that predicts more geographical variation in cold tolerance than heat. Additionally, we suggest that physiological tolerances interact with biotic factors, particularly those related to courtship and mate choice to influence species distributions. Habronattus also had very high warming tolerance values (> 20 °C, on average). Taken together, these data suggest that Habronattus are resilient in the face of climate-change related shifts in temperature.

Rapid population growth, rising water demands, inefficient management, and various distributions of water are the major causes of increased pressure on water resources and the consequent increased water-based conflicts especially in arid and semi-arid regions in Iran being a case in point. Iran is the second largest country in the Middle East. The country-wide average annual precipitation is about 250 mm, which is about one third of the world's average. Therefore, Iran is one of the driest countries in the world. The water supply for human activities in Iran's provinces has become an increasingly complex task. One of the conventional methods to supply water to these regions is through inter-basin water transfers, from water-endowed regions to water-scarce regions. For such projects, it is necessary but also difficult and expensive to estimate the total water storage of every province with traditional methods. This study employs the GRACE satellite data for 2002-2016 are used and develops a method to assess the linkage between water scarcity and conflicts in Iran's provinces. In addition, a transferability index is formulated based on population and conveyable water parameters demonstrating the conditions of the provinces in inter-basin water transfer for reaching equitable compromises. This index leads to an evaluation of the possibility of conflicts arising from inter-basin water transfer projects in Iran. This work's results show that the Bushehr region has a significant amount of conveyable water and low population and hence is suitable to be one of the water-exporting provinces in the inter-basin water projects. The results of this work also demonstrate that the western provinces are likely to experience serious depletion of water resources, and conflicts may arise in the western and central basins due to the changes in water quantity exacerbated by the inter-basin transfer projects.

Plant domestication has strongly modified crop morphology and development. Nevertheless, many crops continue to display atavistic characteristics that were advantageous to their wild ancestors but are deleterious under cultivation, such as pod dehiscence (PD). Here, we provide the first comprehensive assessment of the inheritance of PD in the common bean (Phaseolus vulgaris), a major domesticated grain legume. Using three methods to evaluate the PD phenotype, we identified multiple, unlinked genetic regions controlling PD in a biparental population and two diversity panels. Subsequently, we assessed patterns of orthology among these loci and those controlling the trait in other species. Our results show that different genes were selected in each domestication and ecogeographic race. A chromosome Pv03 dirigent-like gene, involved in lignin biosynthesis, showed a base-pair substitution that is associated with decreased PD. This haplotype may underlie the expansion of Mesoamerican domesticates into northern Mexico, where arid conditions promote PD. The rise in frequency of the decreased-PD haplotype may be a consequence of the markedly different fitness landscape imposed by domestication. Environmental dependency and genetic redundancy can explain the maintenance of atavistic traits under domestication.

Biological soil crusts (biocrusts) are photosynthetic "hot spots" in deserts and cover ∼12% of the Earth's terrestrial surface, and yet they face an uncertain future given expected shifts in rainfall events. Laboratory wetting of biocrust communities is known to cause a bloom of Firmicutes which rapidly become dominant community members within 2 days after emerging from a sporulated state. We hypothesized that their bacteriophages (phages) would respond to such a dramatic increase in their host's abundance. In our experiment, wetting caused Firmicutes to bloom and triggered a significant depletion of cyanobacterial diversity. We used genome-resolved metagenomics to link phage to their hosts and found that the bloom of the genus Bacillus correlated with a dramatic increase in the number of Caudovirales phages targeting these diverse spore-formers (r = 0.762). After 2 days, we observed dramatic reductions in the relative abundances of Bacillus, while the number of Bacillus phages continued to increase, suggestive of a predator-prey relationship. We found predicted auxiliary metabolic genes (AMGs) associated with sporulation in several Caudovirales genomes, suggesting that phages may influence and even benefit from sporulation dynamics in biocrusts. Prophage elements and CRISPR-Cas repeats in Firmicutes metagenome-assembled genomes (MAGs) provide evidence of recent infection events by phages, which were corroborated by mapping viral contigs to their host MAGs. Combined, these findings suggest that the blooming Firmicutes become primary targets for biocrust Caudovirales phages, consistent with the classical "kill-the-winner" hypothesis.IMPORTANCE This work forms part of an overarching research theme studying the effects of a changing climate on biological soil crust (biocrust) in the Southwestern United States. To our knowledge, this study was the first to characterize bacteriophages in biocrust and offers a view into the ecology of phages in response to a laboratory wetting experiment. The phages identified here represent lineages of Caudovirales, and we found that the dynamics of their interactions with their Firmicutes hosts explain the collapse of a bacterial bloom that was induced by wetting. Moreover, we show that phages carried host-altering metabolic genes and found evidence of proviral infection and CRISPR-Cas repeats within host genomes. Our results suggest that phages exert controls on population density by lysing dominant bacterial hosts and that they further impact biocrust by acquiring host genes for sporulation. Future research should explore how dominant these phages are in other biocrust communities and quantify how much the control and lysis of blooming populations contributes to nutrient cycling in biocrusts.

With the growth in the solar photovoltaic (PV) market, there is a renewed interest in increasing the system’s annual produced energy. Most of the proposed solutions in the literature require special additional equipment, which might adversely affect the cost of the produced energy. This paper proposes an integrated PV-reflector system that augments the solar irradiance on already installed PV modules. A new mathematical model has been developed in MATLAB R2020a to simulate and techno-economically assess the proposed integrated PV system during the entire year using real meteorological data. A genetic algorithm has been employed in MATLAB R2020a to obtain the optimal geometric and optical parameters that maximize the annual produced energy and minimize the Levelized Cost of Electricity (LCOE) at two selected locations (Cairo in Egypt and Ma’an in Jordan) and for three module technologies (monocrystalline, polycrystalline, and thin film) and different commercial reflectors. The optimal system configurations increased the annual energy production by up to 6.05, 5.14, and 8.34% for the three PV technologies, respectively. For both locations, the optimal tilt angles of the PV module and reflector range between 24° and 34° for Cairo, and between 19° and 36° for Ma’an, depending on the PV technology. Finally, all the system configurations have favorable and low payback periods (∼3 and 6.5 years for Ma’an and Cairo, respectively), as well as attractive LCOE, which varies between 0.0369 and 0.044 USD/kWh in Ma’an and between 0.0543 and 0.065 USD/kWh in Cairo.

Modern building materials using reinforced concrete are considered the most popular in the production of housing in Algeria, specifically in desert areas such as the city of Ouargla, which is characterized by its hot and arid climate. These dwellings must be more adaptable to this difficult climate. An example is the Ouargla Ksar, which contains traditional dwellings that have proven their effectiveness in terms of the heat problem, as has been revealed in several previously conducted studies, but these dwellings have decreased in demand as they are not suitable for contemporary urban life. Therefore, the aim of this study is to improve the performance of the most recognized house typologies in the city of Ouargla in terms of thermal comfort and energy consumption by using passive strategies. In this regard, we used a research methodology based on field measurements and model simulations wherein we adopted TRNSYS 17 to determine the most often encountered problems. The simulated model was validated by statistical correlation; afterward, a simulation of a full year was run, during which many aspects of construction were studied and compared, such as insulation, the mass of the roof and walls, dimensions and types of windows, orientation, and solar shading. The results show that the studied modern house can be considered inappropriate for a desert climate, and the use of solar shading combined with insulated walls and roof allows for an increase of 35% in annual thermal comfort hours (−0.5 ≤ PMV ≤0.5) and for a 22.73% reduction in the energy consumption. We then compared the simulated scenarios with a traditional house characterized by a bioclimatic architectural design that we used as a reference building. The obtained results may be useful in guiding both refurbishment interventions on existing buildings and the design of new ones. Although the simulated interventions have been widely studied in the literature, it is very important to determine their impact on the perception of the indoor environment and on the energy consumption in this specific geographic area. [ABSTRACT FROM AUTHOR]

In this study, a one-year experiment has been conducted to evaluate the performances of two different photovoltaic technologies: Polycrystalline (pc-Si) and cadmium telluride (CdTe) under a hot desert climate in Mid-south Morocco. For this reason, two PV modules (from each technology) have been exposed and all electrical parameters were monitored for performance comparison. Also, for a realistic comparison, the impact of the climatic parameters, mainly soiling and temperature were taken into consideration. Results show that both technologies have a good performance with a daily Performance Ratio (PR) close to 1 for the pc-Si and around 0.9 for CdTe, but with superiority of 3.5% to the pc-Si technology. The peak daily energy yields are of 7.51 kWh/kWp and 6.99 kWh/kWp for pc-Si and CdTe respectively, with 7% high production for the pc-Si. Nevertheless, the CdTe is less affected by temperature, where the average PR deviation (between the technologies) is 4.37% for temperature values less than 25 °C and 2.35% for temperatures above 25 °C in favor of the CdTe. Regarding soiling, the CdTe shows high performance in comparison to the pc-Si where the daily Soiling Rate reaches 24.6% and 26.9% for both technologies respectively, which causes a drop in the electricity production of 25.5% for the pc-Si and 23.2% for CdTe technology. [ABSTRACT FROM AUTHOR]

Climate change threatens global biodiversity by increasing extinction risk, yet few studies have uncovered a physiological basis of climate-driven species declines. Maintaining a stable body temperature is a fundamental requirement for homeothermic animals, and water is a vital resource that facilitates thermoregulation through evaporative cooling, especially in hot environments. Here, we explore the potential for thermoregulatory costs to underlie the community collapse of birds in the Mojave Desert over the past century in response to climate change. The probability of persistence was lowest for species occupying the warmest and driest sites, which imposed the greatest cooling costs. We developed a general model of heat flux to evaluate whether water requirements for evaporative cooling contributed to species' declines by simulating thermoregulatory costs in the Mojave Desert for 50 bird species representing the range of observed declines. Bird species' declines were positively associated with climate-driven increases in water requirements for evaporative cooling and exacerbated by large body size, especially for species with animal-based diets. Species exhibiting reductions in body size across their range saved up to 14% in cooling costs and experienced less decline than species without size reductions, suggesting total cooling costs as a mechanism underlying Bergmann's rule. Reductions in body size, however, are unlikely to offset the 50 to 78% increase in cooling costs threatening desert birds from future climate change. As climate change spreads warm, dry conditions across the planet, water requirements are increasingly likely to drive population declines, providing a physiological basis for climate-driven extinctions.

For many decades, researchers have studied how plants use bet-hedging strategies to insure against unpredictable, unfavourable conditions. We improve upon earlier analyses by explicitly accounting for how variable precipitation affects annual plant species' bet-hedging strategies. We consider how the survival rates of dormant seeds (in a 'seed bank') interact with precipitation responses to influence optimal germination strategies. Specifically, we incorporate how response to resource availability (i.e. the amount of offspring (seeds) generated per plant in response to variation in desert rainfall) influences the evolution of germination fractions. Using data from 10 Sonoran Desert annual plants, we develop models that explicitly include these responses to model fitness as a function of precipitation. For each of the species, we identify the predicted evolutionarily stable strategies (ESSs) for the fraction of seeds germinating each year and then compare our estimated ESS values to the observed germination fractions. We also explore the relative importance of seed survival and precipitation responses in shaping germination strategies by regressing ESS values and observed germination fractions against these traits. We find that germination fractions are lower for species with higher seed survival, with lower reproductive success in dry years, and with better yield responses in wet years. These results illuminate the evolution of bet-hedging strategies in an iconic system, and provide a framework for predicting how current and future environmental conditions may reshape those strategies.

A recent global trend toward retirement of farmland presents opportunities to reclaim habitat for threatened and endangered species. We examine habitat restoration opportunities in one of the world's most converted landscapes, California's San Joaquin Desert (SJD). Despite the presence of 35 threatened and endangered species, agricultural expansion continues to drive habitat loss in the SJD, even as marginal farmland is retired. Over the next decades a combination of factors, including salinization, climate change, and historical groundwater overdraft, are projected to lead to the retirement of more than 2,000 km2 of farmland in the SJD. To promote strategic habitat protection and restoration, we conducted a quantitative assessment of habitat loss and fragmentation, habitat suitability, climatic niche stability, climate change impacts, habitat protection, and reintroduction opportunities for an umbrella species of the SJD, the endangered blunt-nosed leopard lizard (Gambelia sila). We use our suitability models, in conjunction with modern and historical land use maps, to estimate the historical and modern rate of habitat loss to development. The estimated amount of habitat lost since the species became protected under endangered species law in 1967 is greater than the total amount of habitat currently protected through public ownership and conservation easement. We document climatic niche contraction and associated range contraction away from the more mesic margins of the species' historical distribution, driven by the anthropogenic introduction of exotic grasses and forbs. The impact of exotic species on G. sila range dynamics appears to be still unfolding. Finally, we use NASA fallowed area maps to identify 610 km2 of fallowed or retired agricultural land with high potential to again serve as habitat. We discuss conservation strategies in light of the potential for habitat restoration and multiple drivers of ongoing and historical habitat loss.

Herbivores alter plant biodiversity (species richness) in many of the world's ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis-that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally.

Deserts cover a vast area of the world's land surface, but the study of desert climate has been impeded by the lack of ground meteorological observations. In recent years, the climate reanalysis products provide an important data source to investigate climate change in observation-limited areas. However, their accuracy in desert regions has been poorly investigated. Here, we evaluated the performance of the latest ERA5 reanalysis datasets for the climatic conditions over the deserts of northern China (DNC), including temperature and precipitation variations, climate extremes, and detection skills of daily precipitation. The results show that ERA5 well captures the observed pattern of annual and seasonal temperatures, as well as the warming trend during the past four decades in DNC, compared to the ground observations. However, both annual and seasonal precipitations are greatly overestimated over DNC, and large uncertainties exist in precipitation trends. In addition, the variability of interannual precipitation, precipitation intensity, maximum 1-day precipitation, and the number of continuous dry days are underestimated by ERA5. The bias of precipitation estimates may be traced to the overestimation of rainfall occurrence in ERA5. Comparing to other reanalysis (such as MERRA2, NCEP/NCAR, and NOAA-20C), the ERA5 outperforms them for precipitation and precipitation extremes over DNC, although its performance is not as good as gridded gauge-based precipitation datasets (such as CPC). Overall, this study provides references for the use of ERA5 over DNC and facilitates the applications of ERA5 over other observation-limited desert regions. [ABSTRACT FROM AUTHOR]

Climate change has caused deserts, already defined by climatic extremes, to warm and dry more rapidly than other ecoregions in the contiguous United States over the last 50 years. Desert birds persist near the edge of their physiological limits, and climate change could cause lethal dehydration and hyperthermia, leading to decline or extirpation of some species. We evaluated how desert birds have responded to climate and habitat change by resurveying historic sites throughout the Mojave Desert that were originally surveyed for avian diversity during the early 20th century by Joseph Grinnell and colleagues. We found strong evidence of an avian community in collapse. Sites lost on average 43% of their species, and occupancy probability declined significantly for 39 of 135 breeding birds. The common raven was the only native species to substantially increase across survey sites. Climate change, particularly decline in precipitation, was the most important driver of site-level persistence, while habitat change had a secondary influence. Habitat preference and diet were the two most important species traits associated with occupancy change. The presence of surface water reduced the loss of site-level richness, creating refugia. The collapse of the avian community over the past century may indicate a larger imbalance in the Mojave and provide an early warning of future ecosystem disintegration, given climate models unanimously predict an increasingly dry and hot future.

Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant or dead cells. Although microbial biomass and diversity decrease with increasing aridity in the Atacama Desert, we provide multiple lines of evidence for the presence of an at times metabolically active, microbial community in one of the driest places on Earth. We base this observation on four major lines of evidence: (i) a physico-chemical characterization of the soil habitability after an exceptional rain event, (ii) identified biomolecules indicative of potentially active cells [e.g., presence of ATP, phospholipid fatty acids (PLFAs), metabolites, and enzymatic activity], (iii) measurements of in situ replication rates of genomes of uncultivated bacteria reconstructed from selected samples, and (iv) microbial community patterns specific to soil parameters and depths. We infer that the microbial populations have undergone selection and adaptation in response to their specific soil microenvironment and in particular to the degree of aridity. Collectively, our results highlight that even the hyperarid Atacama Desert can provide a habitable environment for microorganisms that allows them to become metabolically active following an episodic increase in moisture and that once it decreases, so does the activity of the microbiota. These results have implications for the prospect of life on other planets such as Mars, which has transitioned from an earlier wetter environment to today's extreme hyperaridity.

Understanding of avian nocturnal flight comes mainly from northern hemisphere species in seasonal temperate ecosystems where nocturnal flight is often precisely timed and entrained by annual photoperiod. Here we investigate patterns of nocturnal flight in waterbirds of Australian desert ecosystems that fly considerable distances to find temporary water bodies formed from rainfall which is highly unpredictable seasonally and spatially, and when there is sufficient water, they then breed. How they perform these feats of navigation and physiology remain poorly known. Using GPS tracking of 38 satellite tagged Pacific black ducks (Anas superciliosa) in two contrasting ecosystems, before and after heavy rainfall we revealed a key role for facultative nocturnal flight in the movement ecology of this species. After large rainfall events, birds rapidly increased nocturnal flight activity in the arid aseasonal ecosystem, but not in the mesic seasonal one. Nocturnal flights occurred throughout the night in both ecosystems. Long range flights (>50 km in 2 hours) occurred almost exclusively at night; at night the distance flown was higher than during the day, birds visited more locations, and the locations were more widely dispersed. Our work reveals that heavy rainfall triggers increased nocturnal flight activity in desert populations of waterbirds.

Coordination between stem photosynthesis and hydraulics in green-stemmed desert plants is important for understanding the physiology of stem photosynthesis and possible drought responses. Plants with photosynthetic stems have extra carbon gain that can help cope with the detrimental effects of drought. We studied photosynthetic, hydraulic and functional traits of 11 plant species with photosynthetic stems from three California desert locations. We compared relationships among traits between wet and dry seasons to test the effect of seasonality on these relationships. Finally, we compared stem trait relationships with analogous relationships in the leaf economics spectrum. We found that photosynthetic and hydraulic traits are coordinated in photosynthetic stems. The slope or intercept of all trait relationships was mediated by seasonality. The relationship between mass-based stem photosynthetic CO2 assimilation rate (Amass ) and specific stem area (SSA; stem surface area to dry mass ratio) was statistically indistinguishable from the leaf economics spectrum. Our results indicate that photosynthetic stems behave like leaves in the coordination of multiple traits related to carbon gain, water movement and water loss. Because of the similarity of the stem Amass -SSA relationship to the leaf Amass -specific leaf area relationship, we suggest the existence of a photosynthetic stem economic spectrum.

• A detailed simulation data based on PVsyst software and compared with experimental results of an 11.28 kWp grid-connected solar system with sun tracking systems. • The outcomes indicate that the binary-axis solar tracker shows a preferable performance, which collects about 20.89% further energy compared to that of the steady axis. • The energy generated (EDC) over the monitored period (2021) was 6917.50 kWh, 7810.58 kWh, and 8362.68 kWh for the steady PV system, one axis PV system, and twin axis tracking PV system, respectively. • The amount of CO2 emissions avoided over the monitored period (2021) is 4.84 tons, 5.46 tons, and 5.85 tons for the stationary PV system, one axis PV system, and twin axis tracking PV system, respectively. In recent years, the demand for grid tied solar photovoltaic systems has been rising fleetly, due to the low cost of solar panels, storage systems, and inverter equipment. The expertise of the grid related photovoltaic solar system attached sun trackers doesn't depend on the following factors, the amount of sunshine, angular travel, positioning frequency, and the region where they are installed. To comprehend how they perform in the whole world, we require assessing and comparing their performance in several parts of the country. This work details the experimental PV system setup and the analytics based on the measurements from the system in Algeria (Ghardaia City).This work exhibits detailed simulation data based on PVSYST software and compared with experimental results of an 11.28 kWp grid-connected solar system with sun tracking systems, after one year of operation at Applied Research Unit of Renewable Energy (URAER) in southern Algeria. The PV system consists of three identical 3.76 kWp solar trackers systems with the same module and inverter. This study also investigates during the real outdoor PV system operation, the yearly, monthly, and daily PV array and inverter behavior based on the performance metrics indicators, meteorological data (temperature and solar irradiation), DC and AC energy produced reference yield (YF), array yield (YA), final yield (YF), PV array and system efficiency, performance ratio (PR), PV array and system losses, and capacity factor (CF) of the whole solar photovoltaic system with sun tracker and likewise the three sub-PV systems with sun tracker following to the IEC 61,724 guidance. The electricity produced for the grid was also verified using the sunny portal application. The outcomes indicate that the binary-axis solar tracker shows a preferable performance, which collects about 20.89% further energy compared to that of the steady axis, and the one-axis tracker generates about 12.91% more energy compared to the fixed PV tracker. The energy generated (EDC) over the monitored period (2021) was 6917.50 kWh, 7810.58 kWh, and 8362.68 kWh for the steady PV system, one axis PV system, and twin axis tracking PV system, respectively. The yearly energy fed into the conventional network (EAC) over the period is 7537.4 kWh, 9962.1 kWh, and 10273.5 kWh for the stationary PV system, one axis PV system, and binary axis tracking PV system, respectively. The amount of CO 2 emissions avoided over the monitored period (2021) is 4.84 tons, 5.46 tons, and 5.85 tons for the stationary PV system, one axis PV system, and twin axis tracking PV system, respectively, which can significantly contribute to cleaning the environment from pollution. The analysis shows PV module and overall system efficiency varies from (10.66%/10.26%), 10.77%/10.35%, and 10.79%/10.36% noted in July to (12.18%/11.74%, 12.34%/11.9%, and 12.41%/11.95%) noted in January for twin axis solar trackers PV systems, one axis solar trackers PV systems, and PV fixed PV systems, respectively. The analysis shows that the performance ratio (PR) varies from (72.3%, 72.4% and 71.8%) in July to (83.6%, 83.2% and 82.1%) in January and the annual average value reaches (77.95%, 77.80%, and 76.95%) for twin axis solar trackers PV systems, one axis solar trackers PV systems, and PV fixed PV systems, respectively. These performance indicators have the practical value of guiding and providing good feedback for engineers, system designers, contractors, and investors to boost the growing applications of grid-tied PV systems with a sun tracker in the same or similar location and climate conditions (Sahara environment). [ABSTRACT FROM AUTHOR]

Arid soils present unique challenges and opportunities for studying microbial diversity and bioactive potential due to the extreme environmental conditions they bear. This review article investigates soil metagenomics as an emerging tool to explore complex microbial dynamics and unexplored bioactive potential in harsh environments. Utilizing advanced metagenomic techniques, diverse microbial populations that grow under extreme conditions such as high temperatures, salinity, high pH levels, and exposure to metals and radiation can be studied. The use of extremophiles to discover novel natural products and biocatalysts emphasizes the role of functional metagenomics in identifying enzymes and secondary metabolites for industrial and pharmaceutical purposes. Metagenomic sequencing uncovers a complex network of microbial diversity, offering significant potential for discovering new bioactive compounds. Functional metagenomics, connecting taxonomic diversity to genetic capabilities, provides a pathway to identify microbes' mechanisms to synthesize valuable secondary metabolites and other bioactive substances. Contrary to the common perception of desert soil as barren land, the metagenomic analysis reveals a rich diversity of life forms adept at extreme survival. It provides valuable findings into their resilience and potential applications in biotechnology. Moreover, the challenges associated with metagenomics in arid soils, such as low microbial biomass, high DNA degradation rates, and DNA extraction inhibitors and strategies to overcome these issues, outline the latest advancements in extraction methods, high-throughput sequencing, and bioinformatics. The importance of metagenomics for investigating diverse environments opens the way for future research to develop sustainable solutions in agriculture, industry, and medicine. Extensive studies are necessary to utilize the full potential of these powerful microbial communities. This research will significantly improve our understanding of microbial ecology and biotechnology in arid environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Water resources are essential for desert oases and are key drivers of local ecological processes critical to the growth of desert vegetation. In this study, the oasis in the hinterland of the Taklamakan Desert, China, was selected as the research subject. Using high-precision classification of oasis vegetation through machine learning, surface water within the oasis was identified and extracted from multi-year Landsat remote sensing data. The spatial distribution patterns of the main community-building species, Populus euphratica and Tamarix ramosissima, were studied under different moisture gradients using environmental covariates and measured groundwater depth to invert its spatial distribution and K-mean clustering to construct surface water and groundwater moisture gradients. The results indicated that the classification accuracy for the two species reached 0.917. Gradients 1-5 were used to categorize the water resources, dividing surface water and groundwater into five gradients. Gradient 3 exhibited the optimal moisture conditions, with a high surface water distribution frequency (0.017) and shallow groundwater depth (3.158 m), while Gradient 4 showed the least optimal moisture conditions, characterized by a low surface water distribution frequency (0.008) and deep groundwater depth (4.820 m). The water gradient decreased in the following order: Gradient 3 > Gradient 5 > Gradient 1 > Gradient 2 > Gradient 4. The optimum gradients for growth of P. euphratica and T. ramosissima were gradients 5, 1, and 2. The normalized vegetation index spatial distribution patterns of the two species were consistent with that of the moisture gradient. Tamarix ramosissima was found to be more tolerant to salinity and drought than P. euphratica. Overall, this study provides valuable information on the effect of the spatial distribution of water resource gradients on oasis vegetation and can guide future water delivery policies in oases., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that may have influenced the work reported in this study., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ongoing warming will influence plant photosynthesis via thermal effects and by enhancing water deficit. As the primary limiting factor for the growth and development of plants in arid deserts, water may alter the potential warming effects on plant photosynthesis and lead to increased uncertainty in plant dynamics. Here, we used open-top chambers (OTCs) to evaluate the impacts of in situ warming (+0.5 and +1.5 °C) on the photosynthesis and growth of two representative desert plants, Artemisia ordosica and Grubovia dasyphylla, from wet to dry spells. The plant traits associated with photosynthetic diffusive and biochemical processes were also measured to explore the underlying mechanisms involved. We found that warming significantly increased the net photosynthetic rate (A net ) during wet spells under 1.5 °C warming in both plants, while only increased that of A. ordosica under 0.5 °C warming. During dry spells, A net decreased both in A. ordosica and G. dasyphylla, with the rates of declining being 48 % and 41 %, respectively, higher than control under warming. Consequently, warming significantly amplified photosynthetic responses to drought events, which offset the positive warming effects during wet spells and led to unchanged plant biomass in both species. Besides, alterations in plant traits tended to be associated with positive warming effects during wet spells, and the negative effects of drought were mainly due to stomatal limitation. Our results emphasised that the potential benefits of warming during wet spells may be reversed during drought events. Thus, the adverse effects of ongoing warming on desert productivity may increase during dry spells in growing seasons and during dry years., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, exploratory data analysis (EDA) methods, specifically boxplots, were employed to examine the composition of stream sediments in the Collo area of Northeast Algeria. The region's diverse lithological formations, interactions between permanent and temporary watercourses, intermittent flash floods, rugged topography, and fluctuating climatic conditions contribute significantly to data variability. Utilizing the boxplot's capabilities, our analytical approach successfully identified outliers, recorded the actual distribution of data, and determined skewness without the need for prior data processing, often required in conventional statistical studies. The boxplot proved to be an effective tool, offering insights into the geographical distribution of elemental concentrations, including iron (Fe), zinc (Zn), copper (Cu), arsenic (As), chromium (Cr), and lead (Pb). Geochemical mapping, driven by a robust class selection mechanism developed from the boxplot, revealed strong geographical correlations. A notable northeastern anomaly, characterized by elevated concentrations of Pb, Zn, Cu, and As, aligned with known base-metal sulfide and arsenopyrite mineralization sites. Additionally, outlier data for Cr indicated proximity to a plagioclase-lherzolite intrusion and known chromite deposits. The geographical distribution of iron, corresponding with known magnetite and hematite resources, was effectively highlighted using robust class selection based on boxplot analysis. This comprehensive investigation underscores the value of EDA methods in identifying mineralization trends amid the complex variability of the Collo area., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Resampling the same satellite image to conduct a multi-scale assessment of desertification can be accompanied by distortion of terrestrial objects and spectral information, which can lead to uncertainty in the generated information. To address this, this study assesses desertification severity in an area of arid and semi-arid climate in the Eastern Mediterranean (Jordan) that is characterised by cloudless scenes using multi-sensor data of the same scene at the same time. To this end, Sentinel-2 at 10 m and 60 m, Landsat-8 at 30 m and MODIS at 250 m and 500 m were collected to extract albedo and modified soil adjusted vegetation index (MSAVI), and subsequently to construct albedo-MSAVI feature space. Using the negative correlation between albedo and MSAVI, desertification degree index (DDI) was generated. The resulting multi-scale DDI maps bear a relative resemblance in terms of spatial distribution, patterns, and proportions. The DDI maps indicate that extremely serious and serious desertification are widespread, accounting for 50% of the study area, primarily in the eastern portions. However, finer DDI maps (10 m, 30 m and 60 m) are essential for detecting small-scale desertification characteristics due to their ability to capture local spatial variabilities, while coarser ones (250 m and 500 m) are better suited for capturing broad-scale desertification patterns driven by climatic factors, in which MODIS data exhibit a relatively higher positive correlation with seasonal average precipitation. Although finer DDI maps show higher accuracy compared to coarser ones, the accuracy of DDI maps of MODIS has shown an increase within a homogeneous landscape. Accordingly, synchronised multi-scale assessment of desertification severity is not only influenced by the spatial resolution but also by the landscape heterogeneity and the type of satellite sensor utilised. The multi-scale approach applied in this study can provide insights on scale-dependent desertification that help in devising overarching mitigation strategies., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Bioaerosols have attracted increasing attention as novel contaminants because of their potential role in the spread of disease. In this study, sampling sites were established in a landfill in northwestern China with the aim of investigating the emission and diffusion characteristics of bioaerosols. The results revealed that the counts of airborne bacteria released by landfill cover area (LCA) and waste dumping area (WDA) located in the landfill area reached 18 193 ± 30 CFU/m 3 and 10 948 ± 105 CFU/m 3 , respectively. These two aeras were the main sources of bioaerosol generation. Meanwhile, Corynebacterium spp., Bacteroidetes spp., and Pseudomonas spp. were identified as potential pathogens. A Gaussian model was applied to simulate the diffusion of the bioaerosols; the influence distance was calculated as 12 km from the boundary of the landfill site. The potential health risks of bioaerosol exposure to on-site workers and nearby residents were calculated and evaluated in terms of aerosol concentration, particle size, and pathogenic bacteria. The present study promotes the recognition of the emission behavior of microorganisms in aerosol particles and provides a basis for controlling bioaerosol contamination from landfill sites, particularly those located in cold and arid northwestern regions of China., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Desert dust is an important source of essential metals for marine primary productivity, especially in oligotrophic systems surrounded by deserts, such as the Red Sea. However, there are very few studies on the effects of dust on reef-building corals and none on the response of corals to heat stress. We therefore supplied dust to two coral species (Stylophora pistillata and Turbinaria reniformis) kept under control conditions (26 °C) or heat stress (32 °C). Since dust releases large amounts of iron (Fe) in seawater, among other metals, the direct effect of different forms of Fe enrichment on coral photosynthesis was also tested. First, our results show that the desert dust altered the coral metallome by increasing the content of metals that are important for coral physiology (e.g. lithium (up to 5-fold), manganese (up to 4-fold in S. pistillata), iron (up to 3-fold in S. pistillata), magnesium (up to 1.3-fold), molybdenum (up to 1.5-fold in S. pistillata)). Overall, metal enrichment improved the photosynthetic performance of corals, especially under thermal stress (e.g. Pgross (up to 2-fold), Pnet (up to 10-fold), chlorophyll (up to 1.5-fold), symbionts (up to 1.6-fold)). However, Fe exposure (ferric chloride or ferric citrate) did not directly improve photosynthesis, suggesting that it is the combination of metals released by the dust, the so-called "metal cocktail effect", that has a positive impact on coral photophysiology. Dust also led to a decrease in Ni uptake (up to 1.4-fold in the symbionts), likely related to the nitrogen metabolism. Finally, we found that the isotopic signature of metals such as iron, zinc and copper is a good indicator of heat stress and dust exposure in corals. In conclusion, desert dust can increase coral resistance to bleaching by supplying corals with essential metals., (© 2024. The Author(s).)

Saline lakes, characterized by high salinity and limited nutrient availability, provide an ideal environment for studying extreme halophiles and their biogeochemical processes. The present study examined prokaryotic microbial communities and their ecological functions in lentic sediments (with the salinity gradient and time series) using 16S rRNA amplicon sequencing and a metagenomic approach. Our findings revealed a negative correlation between microbial diversity and salinity. The notable predominance of Archaea in high-salinity lakes signified a considerable alteration in the composition of the microbial community. The results indicate that elevated salinity promotes homogeneous selection pressures, causing substantial alterations in microbial diversity and community structure, and simultaneously hindering interactions among microorganisms. This results in a notable decrease in the complexity of microbial ecological networks, ultimately influencing the overall ecological functional responses of microbial communities such as carbon fixation, sulfur, and nitrogen metabolism. Overall, our findings reveal salinity drives a notable predominance of Archaea, selects for species adapted to extreme conditions, and decreases microbial community complexity within saline lake ecosystems., (© 2024. The Author(s).)

In semi-arid and arid regions, qanats are a vital water source for agricultural needs. However, many communities are abandoning these traditional and sustainable water supply systems in favor of modern and more productive methods. Consequently, this research aimed to identify the most effective approaches for rejuvenating qanats in the dry and semi-arid areas of Razavi Khorasan province, Iran. To accomplish this goal, a comprehensive strategy was employed by merging the Strengths, Weaknesses, Opportunities, and Threats (SWOT, Best-Worst Method (BWM), and the Weighted Aggregated Sum Product Assessment (WASPAS).Based on interviews with experts in water resources and SWOT analysis, 27 factors affecting the restoration of qanats were identified and weighted with BWM. The results of BWM-WASPAS highlight the crucial role of a holistic approach in reviving qanats. The study findings reveal that the highest scores were obtained by the strategies reforming water governance policies to prioritize sustainable indigenous water resources (SO1) and establish an independent institution for qanat restoration (WT7). Conversely, educational (ST1), informational (SO3), and research (WO4) strategies concerning the revival of qanats were categorized as intermediate priorities. Lastly, strategies associated with farm-level support policies were assigned lower priorities. Accordingly, it is recommended that policymakers in Mashhad give priority to macro-level and institutional policies concerning qanat restoration, considering the current state of indigenous water resources. Additionally, a continued emphasis on research policies and farm-level initiatives is advised., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Arid ecosystems, characterized by severe water scarcity, play a crucial role in preserving Earth's biodiversity and resources. The Tarim Basin in Northwestern China, a typical arid region isolated by the Tianshan Mountains and expansive deserts, provides a special study area for investigating how plant response and adaptation to such environments. Tamarix hispida, a species well adapted to saline-alkaline and drought conditions, dominates in the saline-alkali lands of the Tarim Basin. This study aims to examine the genetic diversity and environmental adaptation of T. hispida in the Tarim Basin. Genomic SNPs for a total of 160 individuals from 17 populations were generated using dd-RAD sequencing approach. Population genetic structure and genetic diversity were analyzed by methods including ADMIXTURE, PCA, and phylogenetic tree. Environmental association analysis (EAA) was performed using LFMM and RDA analyses. The results revealed two major genetic lineages with geographical substitution patterns from west to east, indicating significant gene flow and hybridization. Environmental factors such as Precipitation Seasonality (bio15) and Topsoil Sand Fraction (T&#95;SAND) significantly shaped allele frequencies, supporting the species' genetic adaptability. Several genes associated with environmental adaptation were identified and annotated, highlighting physiological and metabolic processes crucial for survival in arid conditions. The study highlights the role of geographical isolation and environmental factors in shaping genetic structure and adaptive evolution. The identified adaptive genes related to stress tolerance emphasize the species' resilience and highlight the importance of specific physiological and metabolic pathways., (© 2024. The Author(s), under exclusive licence to The Genetics Society.)

Climate warming poses a significant threat to species worldwide, particularly those inhabiting arid and semi-arid regions where extreme temperatures are increasingly prevalent. However, empirical studies investigating how moderate heat events affect the physiological processes of arid and semi-arid animals are largely scarce. To address this knowledge gap, we used an arid and semi-arid lizard species (Phrynocephalus przewalskii) as a study system. We manipulated thermal environments to simulate moderate heat events (43.5 ± 0.3°C during the heating period) for lizards and examined physiological and biochemical traits related to survival, metabolism, locomotion, oxidative stress, and telomere length. We found that the body condition and survival of the lizards were not significantly affected by moderate heat events, despite an increase in body temperature and a decrease in locomotion at high test temperatures were detected. Mechanistically, we found that the lizards exhibited down-regulated metabolic rates and enhanced activities of antioxidative enzymes, resulting in reduced oxidative damage and stable telomere length under moderate heat events. Based on these findings, which indicated a beneficial regulation of fitness by physiological and biochemical processes, we inferred that moderate heat events did not have a detrimental effect on the toad-headed agama, P. przewalskii. Overall, our research contributes to understanding the impacts of moderate heat events on arid and semi-arid species and highlights the adaptive responses and resilience exhibited by the toad-headed agama in the face of climate warming., (© 2023 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.)

Soil salinization, especially in arid environments, is a leading cause of land degradation and desertification. Excessive salt in the soil is detrimental to plants. Plants have developed various sophisticated regulatory mechanisms that allow them to withstand adverse environments. Through cross-adaptation, plants improve their resistance to an adverse condition after experiencing a different kind of adversity. Our analysis of Ammopiptanthus nanus, a desert shrub, showed that mechanical wounding activates the biosynthesis of jasmonic acid (JA) and abscisic acid (ABA), enhancing plasma membrane H + -ATPase activity to establish an electrochemical gradient that promotes Na + extrusion via Na + /H + antiporters. Mechanical wounding reduces K + loss under salt stress, improving the K/Na and maintaining root ion balance. Meanwhile, mechanical damage enhances the activity of antioxidant enzymes and the content of osmotic substances, working together with cellular ions to alleviate water loss and growth inhibition under salt stress. This study provides new insights and approaches for enhancing salt tolerance and stress adaptation in plants by elucidating the signaling mechanisms of cross-adaptation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Soil salinization adversely affects soil fertility and plant growth in arid region worldwide. However, as the drivers of nutrient cycling, the response of microbial communities to soil salinization is poorly understood. This study characterized bacterial communities in different soil layers along a natural salinity gradient in the Karayulgun River Basin, located northwest of the Taklimakan desert in China, using the 16S rRNA Miseq-sequencing technique. The results revealed a significant filtering effect of salinity on the bacterial community in the topsoil. Only the α-diversity (Shannon index) in the topsoil (0-10 cm) significantly decreased with increasing salinity levels, and community dissimilarity in the topsoil was enhanced with increasing salinity, while there was no significant relationship in the subsoil. BugBase predictions revealed that aerobic, facultatively anaerobic, gram-positive, and stress-tolerant bacterial phenotypes in the topsoil was negatively related to salinity. The average degree and number of modules of the bacterial co-occurrence network in the topsoil were lower under higher salinity levels, which contrasted with the trends in the subsoil, suggesting an unstable bacterial network in the topsoil caused by higher salinity. The average path length among bacterial species increased in both soil layers under high salinity conditions. Plant diversity and available nitrogen were the main drivers affecting community composition in the topsoil, while available potassium largely shaped community composition in the subsoil. This study provides solid evidence that bacterial communities adapt to salinity through the adjustment of microbial composition based on soil depth. This information will contribute to the sustainable management of drylands and improved predictions and responses to changes in ecosystems caused by climate change., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

This study investigates the novel approach of synergizing desert vegetation with shelter forests to enhance windbreak efficiency in a transitional zone between the Korla oasis and the Taklimakan Desert, northwest China. Through an extensive field survey and experimental setup, we evaluated the impact of different shelterbelt configurations on wind speed reduction. Three types of shelter forests were examined: multi-row Poplar (Populus alba), single-row Jujube (Ziziphus jujube), and a mixed-species layout combining one row of Jujube and two rows of Poplar trees. Wind speed measurements were recorded at multiple heights across three zones-open field, between desert vegetation and shelterbelt, and leeward of the shelterbelt-over a three-month period (April to June, 2023). The findings reveal a significant reduction in wind speed, particularly on the leeward side, with multi-row and mixed-species configurations proving the most effective. The highest synergistic efficiency, observed in the mixed-species shelter forest, showed a windbreak efficiency improvement of over 20% compared to desert vegetation alone. This study provides new insights into the combined effectiveness of desert vegetation and shelter forests, offering a strategic framework for designing shelterbelts in arid environments. These results underscore the critical role of diverse, structured vegetation arrangements in combating wind erosion and contribute to the development of sustainable ecological management practices for desert regions worldwide., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Aili et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Soil microorganisms mediate several biological processes through the secretion of natural products synthesized in specialized metabolic pathways, yet functional characterization in ecological contexts remains challenging. Using culture-independent metagenomic analyses of microbial DNA derived directly from soil samples, we examined the potential of biosynthetic gene clusters (BGCs) from six bacterial communities distributed along an altitudinal gradient of the Andes Mountains in the Atacama Desert. We mined 38 metagenome-assembled genomes (MAGs) and identified 168 BGCs. Results indicated that most predicted BGCs were classified as non-ribosomal-peptides (NRP), post-translational modified peptides (RiPP), and terpenes, which were mainly identified in genomes of species from Acidobacteriota and Proteobacteria phyla. Based on BGC composition according to types of core biosynthetic genes, six clusters of MAGs were observed, three of them with predominance for a single phylum, of which two also showed specificity to a single sampling site. Comparative analyses of accessory genes in BGCs showed associations between membrane transporters and other protein domains involved in specialized metabolism with classes of biosynthetic cores, such as resistance-nodulation-cell division (RND) multidrug efflux pumps with RiPPs and the iron-dependent transporter TonB with terpenes. Our findings increase knowledge regarding the biosynthetic potential of uncultured bacteria inhabiting pristine locations from one of the oldest and driest nonpolar deserts on Earth.IMPORTANCEMuch of what we know about specialized metabolites in the Atacama Desert, including Andean ecosystems, comes from isolated microorganisms intended for drug development and natural product discovery. To complement research on the metabolic potential of microbes in extreme environments, comparative analyses on functional annotations of biosynthetic gene clusters (BGCs) from uncultivated bacterial genomes were carried out. Results indicated that in general, BGCs encode for structurally unique metabolites and that metagenome-assembled genomes did not show an obvious relationship between the composition of their core biosynthetic potential and taxonomy or geographic distribution. Nevertheless, some members of Acidobacteriota showed a phylogenetic relationship with specific metabolic traits and a few members of Proteobacteria and Desulfobacterota exhibited niche adaptations. Our results emphasize that studying specialized metabolism in environmental samples may significantly contribute to the elucidation of structures, activities, and ecological roles of microbial molecules., Competing Interests: The authors declare no conflict of interest.

Road corridor vegetation plays a vital role in maintaining ecosystem stability and providing essential ecological services, particularly in semi-arid regions where environmental conditions are challenging. In this study, we investigated the functional traits of native and non-native plant species along the N5 highway corridor in the semi-arid region of Punjab, Pakistan. The methodology involved extensive field surveys and systematic sampling of herbaceous vegetation, followed by detailed measurements of functional traits diversity. We classified 38 plant species into native and non-native categories and analyzed their distribution, life forms, leaf spectra, and flowering phenology. Our results revealed distinct patterns in the functional traits of native and non-native species, with non-native species exhibiting larger plant heights, leaf sizes, and leaf surface areas compared to native species. Additionally, native species displayed greater root and stem biomass, indicative of adaptations to nutrient-poor soils and water-limited environments. The findings suggest that non-native species possess traits associated with rapid growth and resource acquisition, enabling them to outcompete native vegetation and establish dominance in roadside ecosystems. These results provide valuable insights for understanding the ecological implications of non-native species and designing effective management strategies to mitigate their impacts on native biodiversity and ecosystem resilience in semi-arid regions., (© 2024. The Author(s).)

Iron homeostasis is vital for normal physiology, but in the majority of circumstances, like iron overload, this equilibrium is upset leading to free iron in the plasma. This condition with excess iron is known as hemochromatosis, which has been linked to many side effects, including cancer and liver cirrhosis. The current research aimed to investigate active molecules from Streptomyces sp. isolated from the extreme environment of Bahawalpur deserts. The strain was characterized using 16 S rRNA sequencing. Chemical analysis of the ethyl acetate cure extract revealed the presence of phenols, flavonoids, alkaloids, and tannins. Multiple ultraviolet (UV) active metabolites that were essential for the stated pharmacological activities were also demonstrated by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Additionally, Gas chromatography/mass spectrometry (GC-MS) analysis revealed the primary constituents of the extract to compose of phenol and ester compounds. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to assess the extract's antioxidant capacity, and the results showed a good half-maximal inhibitory concentration (IC 50 ) value of 0.034 µg/mL in comparison to the positive control ascorbic acid's 0.12 µg/mL. In addition, iron chelation activity of extract showed significant chelation potential at 250 and 125 µg/mL, while 62.5 µg/mL showed only mild chelation of the ferrous ion using ethylene diamine tetra acetic acid (EDTA) as a positive control. Likewise, the extract's cytotoxicity was analyzed through 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using varying concentrations of the extract and showed 51% cytotoxicity at 350 µg/mL and 65% inhibition of cell growth at 700 µg/mL, respectively. The bioactive compounds from Streptomyces sp. demonstrated strong antioxidant and iron chelating potentials and can prolong the cell survival in extreme environment., (© 2024. The Author(s).)