Search Results (199)

Background: Xerophilous scrubland is a semi-desert ecosystem characterized by a wide diversity of shrubs, which have secondary compounds with nutraceutical potential that could be used as feed for livestock, specifically by goats, since this species has developed behavioral and physiological adaptations that allow it to take advantage of the plant resources of said scrubland. Objective: To evaluate the nutraceutical potential of Havardia pallens and Vachellia rigidula, native species of the xerophilous scrubland, when incorporated as ingredients in goat diets. Methods: Integral diets for male goats were prepared, formulated with 35% inclusion of Havardia pallens, Vachellia rigidula, and Medicago sativa, the latter used as a plant control species. The content of flavonoids and total phenols was compared using colorimetric methods, and the antioxidant capacity was measured using the FRAP method. RP-HPLC-ESI-MS characterized the bioactive compounds in the different extracts. Statistical analysis was performed by ANOVA. Results: The aqueous extraction of Vachellia rigidula showed the highest concentration of total phenols ($\overline{\mathrm{x}}$ = 18.22 mg GAE/g⁻¹), followed by the ethanolic extract in the same species ($\overline{\mathrm{x}}$ = 17.045 mg GAE/g⁻¹). Similarly, Vachellia rigidula presented the highest antioxidant capacity ($\overline{\mathrm{x}}$ = 144,711.53 µmol TE/g⁻¹), while Medicago sativa presented the lowest ($\overline{\mathrm{x}}$ = 11,701.92 µmol TE/g). The RP-HPLC-ESI-MS analysis revealed that Vachellia rigidula presented a higher abundance of flavones, catechins, flavonols, methoxyflavones, and tyrosols. However, Harvardia pallens presented higher levels of methoxycinnamic and hydroxycinnamic acids. One-way ANOVA results showed that diets containing 35% Vachellia rigidula and Havardia pallens significantly contrasted (p < 0.05), increased the content of secondary compounds and antioxidant capacity compared to the control species. Furthermore, including Vachellia rigidula led to a significantly higher antioxidant capacity (p < 0.05) than diets with Havardia pallens or Medicago sativa. Conclusions: Incorporating the leguminous shrubs Vachellia rigidula and Havardia pallens into the formulation of comprehensive diets for buck goats improves the content and availability of phenols, flavonoids, and antioxidants. However, in vivo evaluation of these diets is important to determine their physiological and productive effects on the animals. Full article

The desert-steppe transition zone at the southern edge of the Hobq Desert features complex topography and frequent wind/sand activities. To explore the impact of different underlying surfaces and topography on the wind-sand environment in this area, field measurements were conducted to analyze the temporal and spatial variations of sand-moving wind conditions and sand drift potential. The results indicate that the average wind speed, sand-moving wind frequency, sand drift potential and sand transport rate in this area were higher in spring and winter than in summer and fall temporally. Spatially, different underlying surfaces and topographic conditions, the characteristics of the average wind speed, sand-moving wind frequency, sand drift potential and sand transport rate were as follows: quicksand surface > grassland surface > shrub surface, and top of slope > quicksand surface > middle of slope. The predominant annual wind directions and sand-moving wind directions were W, WNW and NW. The sand drift direction was towards the E or ESE in winter and spring. This study provides a theoretical basis and scientific support for the development of targeted sand control measures in the desert-steppe transition zone at the southern edge of the Hobq Desert, thereby maintaining regional ecological sustainability. Full article

The sand-laden airflow fields surrounding Artemisia desertorum Spreng., Reaumuria soongorica, and Hedysarum scoparium were investigated. The study focuses on a configuration of double rows with staggered shrub distribution. Computational Fluid Dynamics (CFD) simulations were employed to model the airflow. The resulting flow field was categorized into five distinct regions. The shelter distances downwind of the shrubs were observed to be 7 H, 6 H, and 6 H for A. desertorum, R. soongorica, and H. scoparium, respectively. The corresponding shelter widths were measured as 3 m, 3 m, and 8 m, respectively. The three kinds of shrubs all formed vortices behind the shrubs. Three shrub species demonstrated distinct wind shelter efficiency ranges: A. desertorum (0.5–4 H), R. soongorica (0.5–3 H), and H. scoparium (0.5–2 H). Optimal shelter effects were observed in different vertical layers: R. soongorica in the low (0–0.2 m), A. desertorum in the medium (0.2–0.7 m), and H. scoparium in the high (0.7–2.2 m) altitude layers. Overall, H. scoparium exhibited the highest sand resistance, followed by A. desertorum Spreng, with R. soongorica demonstrating the least resistance. This study offers theoretical insights for mitigating aeolian environmental degradation, particularly in safeguarding energy and transportation infrastructure in desert regions and promoting sustainable agricultural practices in arid areas. Full article

Despite Qatar’s depressions being ecologically significant for biodiversity in arid desert regions, they remain poorly studied. This study aimed at assessing the floristic diversity of Qatar’s depression habitat and examining the key environmental drivers shaping vegetation patterns. We applied multivariate analyses, including Canonical Correspondence Analysis (CCA) and Two-Way Indicator Species Analysis (TWINSPAN), to understand the environmental factors that shape vegetation communities and classify the depression sites. A total of 139 plant species from 35 families were recorded from 26 depression sites across Qatar. Both therophytes and chamaephytes were the dominant life forms. Biregional chorotypes were the most prevalent among phytogeographical groups. CCA indicated that grazing pressure, latitude, nitrogen concentration, clay content, and soil pH were among the variables that influenced the vegetation patterns of depressions, while longitude and soil carbon content showed marginal significance in explaining the observed floristic variation. TWINSPAN classified the sites into four distinct clusters, each associated with specific indicator species and habitat conditions. Northern depressions supported higher species richness compared to central and southern depressions, which are dominated by sandy soils and experience intensive grazing patterns that reduce the floristic diversity and limited regeneration of key shrubs such as Vachellia tortilis (Forssk.) Galasso & Banfi. This study helps fill a critical knowledge gap about Qatar’s depression habitat, enhancing efforts to conserve these vulnerable ecosystems, identify ecological threats, and better understand patterns of species distribution across arid landscapes. Full article

Ochradenus baccatus Delile (Resedaceae) is a widely distributed desert shrub known for its remarkable growth form plasticity, growing either independently or as a facultative climber on other vegetation. Despite its ecological adaptability, the drivers underlying its dual growth strategy remain poorly understood in arid ecosystems. This study aimed to investigate the growth form plasticity of O. baccatus across diverse ecological gradients in Saudi Arabia and identify key environmental and floristic factors influencing its climbing and independent forms. Field surveys were conducted from 2020 to 2024 across 103 sites, using stratified random sampling. At each site, vegetation data were collected using 50 × 50 m quadrats, and species composition, life form percentage, and O. baccatus behavior were recorded. Results revealed clear ecological separation between behaviors. Climbing individuals were associated with higher elevations, greater tree and shrub cover, and moderate soil fertility, while independent individuals were broadly distributed in herbaceous and open habitats. Diversity indices (Shannon, Simpson, evenness) increased with altitude, particularly in climbing habitats. PERMANOVA confirmed significant differences in species composition between behaviors (p = 0.0001), and SIMPER analysis identified species like Haloxylon salicornicum and Zygophyllum album as key contributors in climbing habitats. Indicator species analysis revealed behavior-specific taxa, while CCA demonstrated that rainfall, soil moisture, and temperature were the strongest environmental predictors of growth behavior. This study highlights the ecological flexibility of O. baccatus and the role of environmental filtering and plant community structure in shaping its growth strategy. These results have implications for the growth form plasticity of desert plants and can be applied to vegetation management and restoration in arid ecosystems. Full article

As a typical desert oasis ecosystem in the arid region of Northwest China, the Ejina Delta plays a crucial role in regional ecological security through its vegetation dynamics and landscape pattern changes. Based on Landsat remote sensing images (1990–2020), runoff data, and vegetation landscape surveys, this study investigated the evolutionary patterns and driving mechanisms of vegetation degradation and restoration processes using Normalized Difference Vegetation Index (NDVI), landscape metrics, and Land Use Transition Matrix (LUTM) methods. The following key findings were obtained: (1) Since the implementation of the Ecological Water Diversion Project (EWDP) in the Heihe River Basin (HRB) in 2000, a significant recovery in vegetation coverage has been observed, with an NDVI growth rate of 0.0187/10 yr, which is five times faster than that in the pre-diversion period. The areas of arbor vegetation, shrubland, and grassland increased to 356.8, 689.5, and 2192.6 km², respectively. However, there is a lag of about five years for the recovery of arbor and shrub compared to grass. (2) The implementation of EWDP has effectively reversed the trend of vegetation degradation, transforming the previously herb-dominated fragmented landscape into a more integrated pattern comprising multiple vegetation types. During the degradation period (1990–2005), the landscape exhibited a high degree of fragmentation, with an average number of patches (NP) reaching 45,875. In the subsequent recovery phase (2005–2010), fragmentation was significantly reduced, with the average NP dropping to 30,628. (3) Stronger vegetation growth and higher NDVI values were observed along the riparian zone, with the West River demonstrating greater restoration effectiveness compared to the East River. This study revealed that EWDP serves as the key factor driving vegetation recovery. To enhance oasis stability, future ecological management strategies should optimize spatiotemporal water allocation while considering differential vegetation responses. Full article

The densities of carbon, nitrogen, and phosphorus (C-N-P) reflect the adaptation and response of desert plants to hyper-arid environments. However, the allocation strategies for biomass and C-N-P densities among various plant life forms remain poorly understood. This study involved the collection of samples representing both aboveground and belowground biomass (to depths of 200 cm) from three desert plant species—both herbaceous and shrubby—and evaluating their C-N-P densities. The investigation focused on the distribution strategies and drivers influencing total C-N-P densities within the plant–soil system. The results indicated that the biomass of the shrub Tamarix ramosissima (8.88 ± 1.22 kg m⁻²) was significantly greater than that of the herbaceous plants Alhagi sparsifolia (0.96 ± 0.15 kg m⁻²) and Karelinia caspia (0.72 ± 0.09 kg m⁻²). The total C density among the three species was observed as follows: T. ramosissima (9.26 ± 0.99 kg m⁻²) > A. sparsifolia (6.21 ± 0.85 kg m⁻²) > K. caspia (6.18 ± 1.12 kg m⁻²). Notably, no significant differences were detected in the total N and P densities across the species. Additionally, for A. sparsifolia and K. caspia, the roots exhibited greater biomass and C-N-P densities. Further analysis revealed that soil pools accounted for 56.34–95.10% of total C density, 90.39–98.63% of total N density, and 99.86–99.97% of total P density in the plant–soil system. The order of total C-N-P densities was established as C > P > N, decoupling total P density from other environmental factors. Total C and N densities in the three plant species were predominantly influenced by soil physicochemical properties, with biotic factors and microbial biomass playing secondary roles. This study improves the understanding of C-N-P densities strategies of dominant vegetation for restoration and sustainable management in hyper-arid deserts. Full article

Nitraria tangutorum (Zygophyllaceae) is an ecologically and economically valuable shrub, locally dominant in the arid and semi-arid deserts of northwest China owing to its exceptional drought resistance and salt tolerance. In this study, environmental variable importance was evaluated within the MaxEnt model using percent-contribution metrics, based on 154 distribution records of N. tangutorum and 14 bioclimatic and soil-related environmental variables. We identified the five key variables of N. tangutorum distribution as follows: Precipitation of the Wettest Quarter (Bio16), Topsoil Sodicity (T_esp), Topsoil Electroconductibility (T_ece), Topsoil Car-bonate or lime content (T_CACO₃), and Precipitation of the Driest Month (Bio14). The constructed MaxEnt model was then used to project the potential distribution areas of N. tangutorum under the four Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5) for both current climate conditions and future climate conditions (2050s and 2090s). The results indicate that, under present-day conditions, high-suitability areas occur primarily in Xinjiang, Gansu, Qinghai, Inner Mongolia, and Ningxia; in future climate scenarios, the suitable habitat for N. tangutorum is anticipated to shrink by the 2050s but is expected to gradually recover by the 2090s. As time progresses, the suitable habitat areas will generally expand towards higher latitude regions. These findings demonstrate N. tangutorum’s strong adaptive potential to climate change and provide a scientific basis for its targeted introduction, cultivation, and long-term management in desert restoration and ecological rehabilitation projects. Full article

Desert shrubs play an important role in the stability of arid and fragile desert ecosystems. However, despite their significant ecological importance, limited research has been performed on shrub drought tolerance strategies at the morphological, physiological, and molecular levels. Therefore, this study focused on the typical desert shrub, Calligonum leucocladum, and analyzed its morphology, physiology, and protein expression under two different habitats: moist low-salt and arid low-salt. The results indicate that drought stress inhibited the growth of C. leucocladum, leading to significant reductions in its plant height, base diameter, and crown width by 14.93%, 49.57%, and 48.49%, respectively. Drought stress triggered a 30% decline in stomatal conductance, whereas homeostasis was observed in net photosynthesis, intercellular CO₂, and transpiration. The soluble sugar content significantly increased by 13.43%, while the starch, soluble protein, and proline content significantly decreased by 20.32%, 10.67%, and 55.61%, respectively. In addition, under drought stress, membrane peroxidation products, reactive oxygen species metabolites, and antioxidant enzyme activities significantly increased. Weighted gene co-expression network analysis revealed 40 proteins that were significantly enriched in the photosynthesis and oxidative phosphorylation pathways through KEGG enrichment analysis. In addition, C. leucocladum maintains photosynthetic homeostasis by enhancing PSII repair (PsbE, PsbL, PsbH) and electron transfer chain efficiency (PetD, nad 2, nad 9), thereby compensating for the insufficient carbon dioxide supply caused by stomatal limitation. This study integrated multidimensional data from morphology, physiology, and proteomics to reveal that C. leucocladum drives a coupled network of photosynthesis, antioxidant, and carbon metabolism through chloroplast translation reprogramming. It maintains photosynthetic homeostasis and osmotic balance under a 30% decrease in stomatal conductance, elucidating the cross-scale regulatory strategy of desert shrubs adapting to extreme drought. Full article

Guayule (Parthenium argentatum A. Gray) is a valuable domestic source for rubber and resin. At its center of origin in the Northern Mexico and Southern Texas deserts, guayule, a perennial shrub, is hybridized with its relative species mariola (Parthenium incanum Kunth). As rubber and resin are the main products derived from guayule, there is interest in using guayule bagasse as a bioenergy feedstock to meet the growing bioenergy and biofuel demands. This study aimed to explore and characterize phenotypic diversity in cell wall constituents (lignin, cellulose, and hemicellulose) and their yields among 51 guayule and mariola genotypes under two irrigation regimes (well-watered and water-stressed). Significant genotypic and environmental effects were observed for lignin, cellulose and hemicellulose concentrations, and yields, indicating the wide genetic variability of the collection for bioenergy-related traits. Moderate to high entry-mean heritability values for lignin, cellulose, and hemicellulose suggest that selection is feasible to enhance genetic gain. Significant positive correlations were found among cellulose and hemicellulose concentrations and yields, indicating the possibility to select multiple traits together during breeding cycles. High positive correlations between rubber and resin and lignin, cellulose, and hemicellulose yields highlight the opportunity to develop guayule germplasm with enhanced multi-use traits for industrial applications. Wide variations in drought stress indices (stress tolerance index, yield index, and yield stability index) underscore the environmental impact on the lignocellulosic traits. Several genotypes were identified with high stress index scores and could be parental candidates for improving guayule for arid and semi-arid sustainable agricultural systems. The current study is the first to characterize the phenotypic diversities in guayule and mariola for lignocellulosic components and yield, providing the foundation for future breeding efforts aimed at enhancing guayule’s value for diverse production goals and environmental conditions. Full article

Factors such as climate change, fire, and overgrazing have been commonly considered the main causes of the global expansion of shrub invasion in grasslands over the past 160 years. Nevertheless, the influence of soil substrates on the progression of shrub encroachment has been insufficiently examined. This study examines the fundamental characteristics of the shrub-encroached desert steppe communities of Caragana tibetica in the Mongolian Plateau. Combining field surveys (field surveys and drone aerial photography) and laboratory experiments, using Spearman’s rank correlation analysis and structural equation modeling (SEM), this research systematically explores the impact of varying degrees of soil sandification on the survival of shrubs and herbaceous plants within these grassland communities. The findings indicate the following: (1) In the eight shrub-encroached grassland plots, the soil exhibited a significantly higher sand content compared to silt and clay, with the sand content generally exceeding 64%. (2) The coverage of shrub species is predominantly influenced by soil factors, particularly the soil sand content. (The path coefficient is 0.56, with p < 0.01). In contrast, herbaceous plants are more strongly influenced by climatic factors. (The path coefficient is 0.83, with p < 0.001). This study examines the response patterns of Caragana tibetica communities to edaphic and climatic factors, highlighting the pivotal role of soil sandification in the initiation and succession of shrub encroachment. The findings furnish a theoretical framework for forecasting future trends in grassland shrub encroachment and provide empirical evidence for the conservation and sustainable management of shrub-encroached grasslands. Full article

This study aimed to explore the impacts of Lactiplantibacillus plantarum (L), Saccharomyces cerevisiae (Y), tannase-producing bacteria (D), cellulase (M), and their combined treatment (L + Y + D + M) on the sensory quality, chemical composition, silage quality, and microbial community of Caragana korshinskii. In light of the scarcity of research on the use of tannase-producing bacteria, Lactiplantibacillus plantarum, Saccharomyces cerevisiae, and cellulase as composite silage additives in the utilization of desert shrubs as feed resources, this study centers on this area and endeavors to offer a novel theoretical foundation for relevant fields. Different microorganisms and enzymes were individually added to 500 g of Caragana korshinskii, and anaerobic fermentation was carried out in an incubator at 40 °C for 14 days. The results show that compared to the control group (CK) without any additives, the sensory evaluation of all treatments improved, with the L + Y + D + M treatment being the best (p < 0.05). All treatments reduced the contents of acid detergent fiber, neutral detergent fiber, and tannin (p < 0.05), while increasing the content of crude protein and relative feeding value (p < 0.05), with the L + Y + D + M treatment showing the most significant effect (p < 0.05). Lactic acid levels significantly increased (p < 0.05) and the pH significantly decreased (p < 0.05) in all treatments, with the L + Y + D + M treatment outperforming the other treatments (p < 0.05). The L + Y + D + M treatment increased the abundance of Lactiplantibacillus plantarum and Weissella (p < 0.05), significantly reduced harmful microbial abundance and diversity (p < 0.05), and improved the microbial community structure in silage. In summary, the addition of Lactiplantibacillus plantarum (L), Saccharomyces cerevisiae (Y), tannase-producing bacteria (D), cellulase (M), and their combined treatment (L + Y + D + M) can promote the silage-related characteristics of Caragana korshinskii, with the L + Y + D + M treatment performing better compared to the other treatments. The research shows that the compound bacterial and enzymatic preparation is more effective than the single-component. The components exert synergistic effects and can effectively enhance the quality aspects of silaged Caragana korshinskii. This research provides theoretical underpinnings for the utilization of Caragana korshinskii as feedstuff. This application has the potential to alleviate feed scarcity, reduce reliance on traditional feed, enhance the stability and diversity of the feed supply system, and thereby drive the development of the animal husbandry industry. Full article

Desert and semi-desert ecosystems cover a large proportion of global land area, but their tree-ring materials had traditionally been studied less intensively than that of forest ecosystems. In this study, we presented the time series of growth rings from eight typical shrub species of the semi-desert region in the northern foot of Yinshan Mountain, Inner Mongolia, China. The results showed that all those shrub species had recognizably demarcated annual rings of main stems, and tree-ring chronologies could been constructed successfully. The climate-growth analysis indicated that the chronologies was positively correlated with precipitation and PDSI but negatively correlated with temperature variables, indicating that drought stress had primary importance in the control of the relative ring width from year to year for those shrub species. Interestingly, the annual growth rate of those shrub species had no noticeable downward trend in recent decades, indicating that shrub growth had not negatively impacted the recently developed warm–dry climate in the sample sites. Our results provide evidence that growth rings in the main stems of shrub species in the northern foot of Yinshan Mountain should be a reliable proxy of annual fluctuation in the semi-desert environment of China. Full article

Shrub encroachment in grasslands has a major impact on soil carbon storage (SOC_S) and soil total nitrogen (STN_S), which affects nutrient cycling and ecosystem processes. We explored the effects of shrub encroachment on SOC_S and STN_S in five grassland types in the Altai Mountains: mountain meadows, temperate meadow steppe, temperate steppe, temperate steppe desert, and temperate desert steppe. Shrub encroachment considerably improved SOC_S and STN_S, with the greatest increases occurring in locations with high encroachment. The interaction between grassland type and encroachment extent also significantly influenced soil properties, including bulk density, soil water content, and microbial carbon and nitrogen. Specifically, SOC_S increased by 16%, 77%, and 129%, and STN_S increased by 43%, 94%, and 127% under low, medium, and high shrub encroachment, respectively. The soil stoichiometry shifted, with C/N ratios decreasing and C/P and N/P ratios increasing with shrub encroachment. Structural equation modeling (SEM) revealed that shrub encroachment indirectly affected SOC_S and STN_S through changes in soil nutrients and climate. Our findings suggest that shrub encroachment promotes soil C sequestration and alters soil nutrient cycling, with implications for grassland management and ecological restoration in the face of global climate change. Full article

Plant species diversity and spatial distribution patterns are critical for understanding ecosystem dynamics in arid and fragile environments. This study investigates the diversity, spatial distribution, and interspecific associations of shrubs and herbaceous plants in the transition zone of the desert oasis located in the Hexi Corridor and southern edge of the Badanjilin Desert, China. Vegetation data were collected across sample plots spanning three counties in Zhangye City. Important values, diversity indices, and spatial distribution metrics were calculated to evaluate plant species dominance and community structure. Interspecific relationships were analyzed using variance ratio (VR), clumping indicators, and corrected χ² tests. The shrub community exhibited low species diversity (H′ = 1.754) and was dominated by Reaumuria songarica (Pall.) Maxim (IV = 111.175), reflecting its superior adaptability to arid conditions. In contrast, the herbaceous community displayed higher diversity (H′ = 2.498), with Aristida adscensionis L. (IV = 48.6174) as the dominant species. Both communities showed predominantly aggregative spatial distribution patterns, influenced by localized resource availability and adaptive strategies. Weak interspecific associations characterized the shrub community, with limited competition among dominant species, while the herbaceous community demonstrated significant negative correlations, indicating stronger resource competition. The study highlights the contrasting diversity and ecological roles of shrubs and herbaceous plants in arid ecosystems, shaped by resource limitations and environmental stressors. Effective conservation strategies are needed to protect dominant species and sustain ecosystem resilience in desert regions. Future research should focus on below-ground interactions and long-term monitoring to enhance understanding of species coexistence and community stability. Full article