Blowin' in the Wind: Mapping the Dispersion of Metal(loid)s From Atacama Mining.

The Atacama Desert's naturally elevated metal(loid)s pose a unique challenge for assessing the environmental impact of mining, particularly for indigenous communities residing in these areas. This study investigates how copper mining influences the dispersion of these elements in the wind-transportable fraction (<75 µm) of surface sediments across an 80 km radius. We employed a multi-pronged approach, utilizing spatial modeling to map element distributions, exponential decay analysis to quantify concentration decline with distance, regime shift modeling to identify dispersion pattern variations, and pollution assessment to evaluate impact. Our results reveal significant mining-driven increases in surface concentrations of copper (Cu), molybdenum (Mo), and arsenic (As). Notably, within the first 20 km, concentrations peaked at 1,016 mg kg⁻1 for Cu, 31 mg kg⁻1 for Mo, and a remarkable 165 mg kg⁻1 for As. Cu and Mo displayed significant dispersion, extending up to 50 km from the source. However, As exhibited the most extensive reach, traveling up to 70 km downwind, highlighting the far-reaching ecological footprint of mining operations. Mineralogical analyses corroborated these findings, identifying mining-related minerals in surface sediments far beyond the immediate mining area. Although pollution indices based on the proposed Local Geochemical Background reveal significant contamination across the study area, establishing accurate pre-industrial baseline values is essential for a more reliable assessment. This study challenges the concept of "natural pollution" by demonstrating that human activities exacerbate baseline metal(loid)s levels. Expanding monitoring protocols is imperative to comprehensively assess the combined effects of multiple emission sources, including mining and natural processes, in safeguarding environmental and human health for future generations.

Evolution of gene networks underlying adaptation to drought stress in the wild tomato Solanum chilense.

Drought stress is a key limitation for plant growth and colonization of arid habitats. We study the evolution of gene expression response to drought stress in a wild tomato, Solanum chilense, naturally occurring in dry habitats in South America. We conduct a transcriptome analysis under standard and drought experimental conditions to identify drought-responsive gene networks and estimate the age of the involved genes. We identify two main regulatory networks corresponding to two typical drought-responsive strategies: cell cycle and fundamental metabolic processes. The metabolic network exhibits a more recent evolutionary origin and a more variable transcriptome response than the cell cycle network (with ancestral origin and higher conservation of the transcriptional response). We also integrate population genomics analyses to reveal positive selection signals acting at the genes of both networks, revealing that genes exhibiting selective sweeps of older age also exhibit greater connectivity in the networks. These findings suggest that adaptive changes first occur at core genes of drought response networks, driving significant network re-wiring, which likely underpins species divergence and further spread into drier habitats. Combining transcriptomics and population genomics approaches, we decipher the timing of gene network evolution for drought stress response in arid habitats.

The design and development of EcoBiomes: Multi-species synthetic microbial consortia inspired by natural desert microbiome to enhance the resilience of climate-sensitive ecosystems.

Synthetic microbial communities, which simplify the complexity of natural ecosystems while retaining their key features, are gaining momentum in engineering and biotechnology applications. One potential application is the development of bioinoculants, offering an eco-friendly, sustainable solution to promote plant growth and increase resilience to abiotic stresses amidst climate change. A potential source for stress-tolerant microbes is those associated with desert plants, evolved and shaped by selective pressures to promote host health under harsh environmental conditions. In our research, we aim to design and develop synthetic microbial consortia inspired by the natural microbiota of four desert plants native to the Arabian Peninsula, inferred from our previous work identifying the structure and predicting the function of these microbial communities using high throughput eDNA barcoding. To obtain culturable microbes that are manageable and traceable yet still representative of natural microbial communities, we combined multiple experimental protocols coupled with compatibility and synergy assessments, along with in planta testing. We isolated a total of 75 bacteria and conducted detailed biological evaluations, revealing that an overwhelming majority (84 %) of all isolates produced indole acetic acid (IAA), with 73 % capable of solubilizing phosphate, 60 % producing siderophores, 47 % forming biofilms, and 35 % producing ACC deaminase, all contributing to plant growth and stress tolerance. We constructed four synthetic microbial consortia, named EcoBiomes, consisting of synergistic combinations of multiple species that can co-exist without significant antagonism. Our preliminary data indicate that EcoBiomes enhance the resilience of heterologous host plants under simulated environmental stresses, including drought, heat, and salinity. EcoBiomes offer a unique, sustainable, and eco-friendly solution to mitigate the impact of climate change on sensitive ecosystems, ultimately affecting global food security.

Regulation of drought stress on nutrient cycle and metabolism of rhizosphere microorganisms in desert riparian forest.

Microbial communities in desert riparian forest ecosystems have developed unique adaptive strategies to thrive in harsh habitats shaped by prolonged exposure to abiotic stressors. However, the influence of drought stress on the functional and metabolic characteristics of soil rhizosphere microorganisms remains unknown. Therefore, this study aimed to investigate the effects of drought stress on soil biogeochemistry and metabolism and analyze the relationship between the biogeochemical cycle processes and network of differentially-expressed metabolites. Using metagenomics and metabolomics, this study explored the microbial functional cycle and differential metabolic pathways within desert riparian forests. The predominant biogeochemical cycles in the study area were the Carbon and Nitrogen cycles, comprising 78.90 % of C, N, Phosphorus, Sulfur and Iron cycles. Drought led to increased soil C fixation, reduced C degradation and methane metabolism, weakened denitrification, and decreased N fixation. Furthermore, drought can disrupt iron homeostasis and reduce its absorption. The differential metabolic pathways of drought stress include flavonoid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and starch and sucrose degradation. Network analysis of functional genes and metabolism revealed a pronounced competitive relationship between the C cycle and metabolic network, whereas the Fe cycle and metabolic network promoted each other, optimizing resource utilization. Partial least squares analysis revealed that drought hindered the expression and metabolic processes and functional genes, whereas the rhizosphere environment facilitated metabolic expression and the functional genes. The rhizosphere effect primarily promoted metabolic processes indirectly through soil enzyme activities. The integrated multi-omics analysis further revealed that the effects of drought and the rhizosphere play a predominant role in shaping soil functional potential and the accumulation of metabolites. These insights deepen our comprehension of desert riparian forest ecosystems and offer strong support for the functionality of nutrient cycling and metabolite dynamics.

Influence of surface water and groundwater gradient on spatial distribution of typical vegetation in the hinterland of Taklamakan desert.

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.

Metagenomic approaches and opportunities in arid soil research.

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.

Amplified photosynthetic responses to drought events offset the positive effects of warming on arid desert plants.

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 (Anet) 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, Anet 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.

[Epidemiological characteristics of visceral leishmaniasis in Gansu Province from 2017 to 2023].

OBJECTIVE: To analyze the epidemiological characteristics of visceral leishmaniasis in Gansu Province from 2017 to 2023, so as to provide insights into formulation of the visceral leishmaniasis control strategy in the province. METHODS: All epidemiological features of confirmed and clinically diagnosed cases of visceral leishmaniasis reported in Gansu Province from January 1, 2017 to December 31, 2023 were retrieved from the Chinese Disease Prevention and Control Information System, and the epidemiological characteristics of visceral leishmaniasis cases were analyzed descriptively. RESULTS: A total of 280 visceral leishmaniasis cases were reported in 39 counties (cities and districts) of Gansu Province from 2017 to 2023, including 258 local cases reported in 21 endemic counties (districts) and 22 imported cases reported in 18 non-endemic areas. Of the 280 cases, there were 262 cases with mountain type zoonotic visceral leishmaniasis (MT-ZVL), 12 cases with desert-type zoonotic visceral leishmaniasis (DT-ZVL), and 6 cases with unknown type. Re-emerging MT-ZVL occurred in Maiji District, Qinzhou District, Lixian County, Kangxian County, Zhenyuan County, Qin'an County and Yongjing County, and re-emerging DT-ZVL occurred in Dunhuang City, while emerging DT-ZVL occurred in Yumen City. The five counties (districts) reporting the highest number of visceral leishmaniasis cases included Wudu District, Wenxian County, Tanchang County, Zhouqu County and Diebu County, and a total of 220 cases were reported in these five counties, accounting for 78.57% of all visceral leishmaniasis cases in the province. Visceral leishmaniasis cases were reported each month throughout the year, with the peak in July. All reported visceral leishmaniasis cases had ages of 6 months to 81 years, including 50.71% (142/280) under 15 years of age, 49.29% (138/280) at ages of 15 years and older, and of all cases under 15 years of age, children at ages of 0 to 3 years were the most commonly affected (27.14%, 76/280). Among 280 visceral leishmaniasis cases, there were 173 males and 107 females with a male to female ratio of 1.62∶1, and farmer was the most common occupation (40.36%), followed by diaspora children (37.86%). CONCLUSIONS: The prevalence of visceral leishmaniasis appeared an overall tendency towards a decline in Gansu Province from 2017 to 2023; however, there are still multiple challenges for visceral leishmaniasis control in the province. Reinforced dog monitoring and management, intensified human health education and improved capability building among professionals are recommended to manage the rebounding and spread of visceral leishmaniasis.

Response of soil fungal-community structure and function to land conversion to agriculture in desert grassland.

Land conversion to agriculture is an important factor affecting soil ecological processes in the desert grasslands of northern China. However, soil fungal-community structure and function in response to Land conversion remain unclear. In this study, desert grassland, artificial shrubland, and land conversion were investigated in the western part of the Mu Us Sandland (Yanchi, Ningxia; Dingbian, Shaanxi). We found that land conversion significantly increased soil total carbon, nitrogen, and phosphorus, and available phosphorous and potassium contents. In the early stage of conversion to agricultural (April), soil fungal operational taxonomic units and abundance-based coverage estimator were lower than those of dessert grasslands and shrubland plots and had significant correlations with pH, electric conductivity, and available phosphorus and potassium. The dominant phyla strongly correlated with soil physicochemical properties. Concomitantly, the relative abundance of Glomeromycota was significantly lower, and the complexity of the network in the land conversion plots was lower than that in the shrubland plots. In the late stage of land conversion (September), soil fungal operational taxonomic units and abundance-based coverage estimator were lower in the conversion plots than in the desert grassland plots, with more complex network relationships compared to the desert grassland or shrubland plots. Symbiotrophic groups, a functional group of desert grassland soil fungi, can be used as a predictor of environmental change; in addition, land conversion decreases the relative abundance of arbuscular mycorrhizal functional groups. Our study highlights the response of soil fungal communities and functions to human disturbances in desert grasslands. Considering the potential of land conversion to agriculture to influence soil secondary salinization, there is a need for continued observation of soil ecological health over the time continuum of land conversion to agriculture.

The Protection and Management of Wapiti in Desert Oases: Bare Land Poses a Limitation to Wapiti Conservation.

The Helan Mountains, situated in the heart of the desert, act as a dividing line between China's arid and semi-arid zones. Often referred to as a "desert oasis", they create an ecological island with a uniquely distinctive geographical location, making this area a focal point of contemporary research. Ungulates play a critical role in this ecosystem. The Alashan wapiti (Cervus canadensis alashanicus), an isolated population of China's smallest wapiti (Cervus canadensis) subspecies, is found exclusively within the Helan Mountains Nature Reserve. The conservation of this isolated population is fraught with challenges, particularly during winter, the harshest season for northern ungulates. Winter habitats are crucial for ensuring population stability. Therefore, we used certain methods, such as factor screening and model parameter optimization to assess habitat suitability using multi-scale species distribution models. The optimized results show that suitable habitats overlap with areas of high vegetation coverage in the Helan Mountains, covering just 588.32 km2, which is less than a quarter of the reserve's total area. The bare land area and winter NDVI are the two primary factors influencing habitat suitability, with other factors having minimal impact, underscoring the critical importance of food resources for the Alashan wapiti. The limited availability of these resources poses significant conservation challenges. Our findings provide a more precise foundation for targeted habitat protection and restoration efforts. We recommend enhancing the protection and restoration of food resources, effectively conserving vegetated areas, and preventing desertification.

Response of Seed Germination and Seedling Growth of Six Desert Shrubs to Different Moisture Levels under Greenhouse Conditions.

Moisture is the most important environmental factor limiting seed regeneration of shrubs in desert areas. Therefore, understanding the effects of moisture changes on seed germination, morphological and physiological traits of shrubs is essential for vegetation restoration in desert areas. In March to June 2023, in a greenhouse using the potting method, we tested the effects of soil moisture changes (5%, 10%, 15%, 20% and 25%) on seed germination and seedling growth of six desert shrubs (Zygophyllum xanthoxylum, Nitraria sibirica, Calligonum mongolicum, Corethrodendron scoparium, Caragana korshinskii, and Corethrodendron fruticosu). Results showed that (1) seed germination percent and vigor index were significantly higher at 15 and 20% soil moisture content than at 5 and 10%; (2) shoot length, primary root length, specific leaf area and biomass of seedlings were significantly higher in the 15% and 20% soil moisture content treatments than in the 5% and 10% treatments; (3) superoxide dismutase activity (SOD) and soluble protein content (SP) decreased with decreasing soil water content, while peroxidase activity (POD) and catalase activity (CAT) showed a decreasing and then increasing trend with increasing soil water content; (4) the six seeds and seedling of shrubs were ranked in order of their survivability in response to changes in soil moisture: Caragana korshinskii > Zygophyllum xanthoxylum > Calligonum mongolicum > Corethrodendron scoparium > Corethrodendron fruticosu > Nitraria sibirica. Our study shows that shrub seedlings respond to water changes by regulating morphological and physiological traits together. More importantly, we found that C. korshinskii, Z. xanthoxylum and C. mongolicum were more survivable when coping with water deficit or extreme precipitation. The results of the study may provide a reference for the selection and cultivation of similar shrubs in desert areas under frequent extreme droughts in the future.

Control of inorganic and organic phosphorus molecules on microbial activity, and the stoichiometry of nutrient cycling in soils in an arid, agricultural ecosystem.

Background: The dynamics of carbon (C), nitrogen (N), and phosphorus (P) in soils determine their fertility and crop growth in agroecosystems. These dynamics depend on microbial metabolism, which in turn depends on nutrient availability. Farmers typically apply either mineral or organic fertilizers to increase the availability of nutrients in soils. Phosphorus, which usually limits plant growth, is one of the most applied nutrients. Our knowledge is limited regarding how different forms of P impact the ability of microbes in soils to produce the enzymes required to release nutrients, such as C, N and P from different substrates. Methods: In this study, we used the arable layer of a calcareous soil obtained from an alfalfa cropland in Cuatro Cienegas, México, to perform an incubation experiment, where five different phosphate molecules were added as treatments substrates: three organic molecules (RNA, adenine monophosphate (AMP) and phytate) and two inorganic molecules (calcium phosphate and ammonium phosphate). Controls did not receive added phosphorus. We measured nutrient dynamics and soil microbial activity after 19 days of incubation. Results: Different P molecules affected potential microbial C mineralization (CO2-C) and enzyme activities, specifically in the organic treatments. P remained immobilized in the microbial biomass (Pmic) regardless of the source of P, suggesting that soil microorganisms were limited by phosphorus. Higher mineralization rates in soil amended with organic P compounds depleted dissolved organic carbon and increased nitrification. The C:N:P stoichiometry of the microbial biomass implied a change in the microbial community which affected the carbon use efficiency (CUE), threshold elemental ratio (TER), and homeostasis. Conclusion: Different organic and inorganic sources of P affect soil microbial community structure and metabolism. This modifies the dynamics of soil C, N and P. These results highlight the importance of considering the composition of organic matter and phosphate compounds used in agriculture since their impact on the microbial activity of the soil can also affect plant productivity.

Distraction Enterogenesis Induces Desert Hedgehog in the Lengthened Murine Colon.

BACKGROUND: Distraction enterogenesis lengthens the intestine through applied mechanical stress. The Hedgehog pathway (Hh) is responsible for intestinal tract development and directing the multi-layer patterning of the intestinal lumen. This study investigates the alteration in the principal components of this pathway in spring-mediated colonic lengthening. METHODS: Samples from the murine cecal lengthening model were used to study Hh alteration during the cecal lengthening process. Primary components of this pathway were analyzed using RT-qPCR and immunostaining after 7 and 14 days of force application. The spring-mediated lengthened segments were compared to untreated control segments within each animal. RESULTS: The spring-treated segments showed a 50% increase in length. There was a significant increase in the expression of the Desert Hedgehog ligand as opposed to the Sonic Hedgehog and Indian Hedgehog ligands. Additionally, the downstream targets of the pathway, Gli1, Gli2, and Gli3, were significantly overexpressed. The highest alterations in these components occurred at the earlier time point, after 7 days. CONCLUSIONS: These findings highlight the contribution of the conserved Hedgehog developmental pathway during mechanical force-induced cecal lengthening, primarily through the Desert Hedgehog ligand. These data suggest that the Desert Hedgehog pathway may serve as therapeutic targets for intestinal regeneration.

The Response of Rhizosphere Microbial C and N-Cycling Gene Abundance of Sand-Fixing Shrub to Stand Age Following Desert Restoration.

Rhizosphere microorganisms play a pivotal role in biogeochemical cycles, particularly in relation to carbon (C) and nitrogen (N) cycles. However, the impact of stand age on the composition of rhizosphere microbial communities and the abundance involved in C and N cycling remains largely unexplored in restoration ecosystems dominated by shrubs of temperate deserts. This study focuses on revealing changes in microbial composition and functional genes in the rhizosphere soil of Caragana korshinskii after revegetation, as well as their response mechanisms to changes in environmental factors. The alpha diversity of bacteria tended to increase with stand age, whereas that of fungi decreased. The abundance of denitrification; dissimilatory nitrate reduction to ammonium, nitrification, and ammonium assimilation; and C fixation-related gene levels increased with stand age, whereas those related to the degradation of starch, pectin, hemicellulose, cellulose, and aromatics decreased. The parameters MBC, MBN, and TC were the key factors affecting the bacterial community, whereas the fungal community was regulated by TN, EC, pH, and MBC. Stand age indirectly regulated C and N cycling functions of genes through altered soil properties and microbial community structures. This study presents a novel approach to accurately evaluate the C and N cycling dynamics within ecosystems at various stages of restoration.

Effect of Drought and Rehydration on Physiological Characteristics of Agriophyllum squarrosum (L.) Moq. in Different Habitats.

Agriophyllum squarrosum (L.) Moq. is a highly prevalent xerophytic species found throughout northern China. It is suitable for cultivation in semi-arid sandy environments and may establish roots in arid desert locations. This species plays a pioneering and exploratory role in the colonization of desert plants. In this study, we selected A. squarrosum from the Urat desert steppe (UD) and Horqin sandy land (HS) to explore their adaptation mechanisms to drought and rehydration environments by using the pot weighing control method to simulate an arid environment. The findings showed that the control (watering to 60-65% of field capacity) exceeded its required amount and the leaves turned yellow. The chlorophyll content was lower than those under moderate and severe drought, and rehydration caused a decrease. However, the contents of malondialdehyde, soluble sugar, and proline in the drought treatment were higher than those in the control. Under moderate and severe drought, the chlorophyll content and the quantum efficiency of photosystem II (Fv/Fm) of A. squarrosum from UD were higher than those from HS. During drought and rehydration processes, the proline content was relatively lower, while the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) and the content of soluble sugar and soluble protein were higher. However, antioxidant enzymes and osmoregulators from UD were higher than those from HS. The results suggest that the stronger ability of A. squarrosum to endure drought environments in UD is due to the high level of antioxidant enzymes and osmoregulators, which are conducive to relieving cell membrane damage when subjected to drought and rehydration.

Desertification indirectly affects soil fauna by reducing complexity of soil habitats and diversity of energy sources.

Soil fauna is closely linked to ecological functions such as biogeochemical cycling, soil structure, ecosystem sustainability and trophic interactions. However, little consideration has been given to how desertification influences the abundance and diversity of soil fauna in arid areas. In this study, soil fauna was sampled in four desert habitats (gravel, sand, salt and mud desert) in northwest China. At the same time, the plant traits, geographic location and soil properties were investigated. We also measured contribution of environmental factors explained faunal community diversity and abundance, and by what pathways desertification controls soil fauna. The results showed that total abundance and diversity of soil fauna in the mud desert were significantly (P < 0.05) higher than salt, sand and gravel deserts. Soil fauna diversity, composition and community were more sensitive to desertification-induced changes in soil properties than to changes in plant traits and geographic locations (changes in soil properties explained 68.9 % and 73.7 % of the variation in diversity and abundance of soil fauna community, respectively). Among them, the available phosphorus, volumetric water content had a significant positive effect on community diversity and abundance, while pH had a significant negative effect (P < 0.01). The results of piecewise structural equation modeling imply that desertification may have mainly indirect impacts on soil fauna community, and that direct effects are almost zero. In summary, regardless of the type of desertification, it will affect the material cycle, energy flow and information transfer of ecosystems by destroying the soil habitats and vegetation conditions, and will affect the structure and diversity of soil fauna from the bottom up.

The mitochondrial genome of the critically endangered enigmatic Kazakhstani endemic Selevinia betpakdalaensis (Rodentia: Gliridae) and its phylogenetic relationships with other dormouse species.

Dormice (family Gliridae) are an ancient group of rodents. It was fully dominant in the Oligocene and Early Miocene, and its current diversity is represented by a few extant species. A Kazakhstani endemic, the desert dormouse Selevinia betpakdalaensis is one of the most enigmatic dormouse species. Lack of genetic data has not allowed Selevinia to be included in previous molecular phylogenetic analyses. In the current study, we report the first genetic data on S. betpakdalaensis as well as mitochondrial genomes of Myomimus roachi and Glirulus japonicus (retrieved from museum specimens) and a mitogenome of Graphiurus murinus (assembled from SRA data). The assembled mitochondrial genomes were combined with available mitochondrial data from GenBank to reconstruct the mitochondrial phylogeny of Gliridae. Taking into account a distortion of the phylogeny as a result of an analysis of the saturated third codon position, we obtained for the first time a resolved phylogeny of the family. The first split within Gliridae was estimated as an average of 34.6 Mya, whereas divergence time of subfamilies Graphiurinae and Glirinae was assessed at 32.67 Mya. The phylogenetic analysis confirmed the relationship (previously shown based on cranial and mandibular morphology) between Selevinia and the Myomimus.

Assessment of the ecological and environmental effects of large-scale photovoltaic development in desert areas.

Photovoltaic development has played a crucial role in mitigating the energy crisis and addressing global climate change. However, it has also had significant impacts on the ecological environment. To ensure the sustainable growth of the photovoltaic industry, it is essential to establish an indicator system to assess the ecological and environmental effects of photovoltaic development. This study utilizes the Driving-Pressure-Status-Impact-Response (DPSIR) framework to create an indicator system for evaluating the ecological and environmental effects of desert photovoltaic development. The study evaluates the ecological and environmental effects at the on-site (WPS), transitional zone (TPS), and off-site (OPS) areas of the Qinghai Gonghe Photovoltaic Park in China. The entropy weight method was utilized to calculate indicator weights, while the evaluation model and indicators were transformed uniformly to obtain standardized scores for ecological and environmental effects. and conducting a thorough analysis of the distribution characteristics and factors influencing the evaluation indicators' scores. Overall, the large-scale development of desert photovoltaics in Gonghe County has had a positive impact on the ecological environment. The WPS had better ecological and environmental conditions than did the TPS and OPS, and the ecological and environmental evaluation levels of the WPS were categorized as "general" (0.439), while the ecological and environmental effect evaluation levels of the TPS (0.286) and OPS (0.28) were both "poor", indicating significant room for improvement. Moreover, all indicators in the scheme layer, which are used to evaluate ecological and environmental quality, yielded higher scores for the WPS than for the TPS and OPS, demonstrating that photovoltaic development has a positive effect on desert area ecology and the environment.

Variation in Root-Associated Microbial Communities among Three Different Plant Species in Natural Desert Ecosystem.

The process and function that underlie the assembly of root-associated microbiomes may be strongly linked to the survival strategy of plants. However, the assembly and functional changes of root-associated microbial communities in different desert plants in natural desert ecosystems are still unclear. Thus, we studied the microbial communities and diversity of root endosphere (RE), rhizosphere soil (RS), and bulk soil (BS) among three representative desert plants (Alhagi sparsifolia, Tamarix ramosissima, and Calligonum caput-medusae) in three Xinjiang desert regions {Taklimakan (CL), Gurbantünggüt (MSW), and Kumtag (TLF)} in China. This study found that the soil properties {electrical conductivity (EC), soil organic carbon (SOC), total nitrogen (TN) and phosphorus (TP), available nitrogen (AN) and phosphorus (AP)} of C. caput-medusae were significantly lower than those of A. sparsifolia and T. ramosissima, while the root nutrients (TN and TP) of A. sparsifolia were significantly higher compared to C. caput-medusae and T. ramosissima. The beta diversity of bacteria and fungi (RE) among the three desert plants was significantly different. The common OTU numbers of bacteria and fungi in three compartments (RE, RS, and BS) of the three desert plants were ranked as RS > BS > RE. The bacterial and fungal (RE) Shannon and Simpson indexes of C. caput-medusae were significantly lower as compared to those of A. sparsifolia and T. ramosissima. Additionally, bacterial and fungal (RE and RS) node numbers and average degree of C. caput-medusae were lower than those found in A. sparsifolia and T. ramosissima. Root and soil nutrients collectively contributed to the composition of root-associated bacterial (RE, 12.4%; RS, 10.6%; BS, 16.6%) and fungal communities (RE, 34.3%; RS, 1.5%; BS, 17.7%). These findings demonstrate variations in the bacterial and fungal populations across different plant species with distinct compartments (RE, RS, and BS) in arid environments. More importantly, the study highlights how much soil and plant nutrients contribute to root-associated microbial communities.

Fine Root Traits across Different Root Orders and Their Associations with Leaf Traits in 15 Co-Occurring Plant Species from the Desert-Oasis Transition Zone in the Hexi Corridor, Gansu Province, China.

Fine root traits embody trade-offs between resource acquisition and conservation in plants. Yet, the differentiation of these traits across root orders, the existence of a root economics spectrum (RES) spanning these orders, and their linkage with leaf traits remain underexplored. In this study, we analyzed the first three root orders and leaf traits of 15 co-occurring plant species, including ten herbs and five shrubs, from the desert-oasis transition zone of the Hexi Corridor. We measured twelve morphological and chemical traits to investigate the relationships between root and leaf traits. Our results revealed significant variation in root traits both among species and within species across different root orders. We identified RES that spanned root orders, with higher-order roots exhibiting more conservative traits and lower-order roots displaying traits aligned with resource acquisition. Additionally, leaf and fine root traits showed partially decoupled adaptive strategies, yet evidence also supported the existence of a leaf economics spectrum (LES) and a potentially two-dimensional whole plant economics spectrum (WPES). Our findings suggest synergistic resource allocation strategies between fine roots and the entire plant, emphasizing the importance of root order in understanding fine root structure, function, and their interactions with other plant organs. These insights advance the understanding of fine root traits and their integration within the broader plant economics spectrum. Nevertheless, the differences in fine root traits across root orders, the presence of a root economics spectrum (RES) spanning these orders, and the relationships between fine root and leaf traits remain underexplored. We examined the first three root orders and leaves of 15 co-occurring plant species (ten herbs and five shrubs) from the desert-oasis transition zone in the Hexi Corridor, measured twelve key morphological and chemical traits. We observed substantial variation in root traits among species and root orders within species. The root economics spectrum (RES) spanned across root orders, with higher-order roots positioned at the conservative end and lower-order roots at the acquisitive end of the "investment-return" strategy axis. Leaf and fine root traits of the 15 co-occurring plant species exhibited partially decoupled adaptive strategies. However, there was also evidence for the presence of a leaf economics spectrum (LES) and a whole plant economics spectrum (WPES), with the WPES potentially being two-dimensional. Furthermore, our findings suggest synergistic resource strategies between fine roots and the whole plant. Concurrently, the significant interspecific and intraspecific differences in fine root traits, combined with the presence of a root economics spectrum across root orders, underscore the critical importance of root order in studying fine root structure, function, and their associations with other plant organs. Our findings offer valuable insights for future research on fine root traits, the RES, and their integration with the whole plant economics spectrum.