The Indian pangolin (Manis crassicaudata), an elusive and endangered mammal, remains poorly studied in Pakistan, particularly in the mountain landscapes of the Lesser Himalayas. This study provides the first detailed ecological baseline of the species' spatial distribution, burrow characteristics, habitat associations, and anthropogenic threats in District Buner, Khyber Pakhtunkhwa, based on systematic field surveys conducted from October 2022 to September 2023. Using a stratified random sampling design, systematic surveys were conducted across 54 km2 of surveyed habitat along line transects and associated circular plots, resulting in the documentation of 127 pangolin burrows across four tehsils. These comprised feeding burrows (63.8%), inactive burrows (26.0%), and active resting (living) burrows (10.2%). The burrow-based abundance patterns indicated that active burrows were primarily recorded between 300 and 700 m elevation, with occasional occurrences up to 1300 m, and were absent above this range. Burrow activity was highest in Mandanr Tehsil and was associated with north- and east-facing slopes, loamy soils, rocky substrates, moderate canopy cover (41%-70%), and dense understory vegetation. Phytohabitat associations showed that resting burrows were frequently linked to Lantana camara and Punica granatum, whereas feeding burrows were commonly associated with Dalbergia sissoo, Acacia modesta, and prey-rich substrates. Burrow concentrations were greatest within ecotonal zones between scrub forest and subtropical pine forest, while areas dominated by Pinus roxburghii, Juglans regia, and Quercus incana showed no evidence of pangolin presence. Two direct sightings and physical remains provided independent confirmation of species presence and suggested localized decline at some sites. Major threats identified through field observations and community surveys included poaching, illegal trade, habitat degradation, marble mining, and unregulated infrastructure development, exacerbated by weak law enforcement and low local awareness. This study provides a robust ecological baseline for M. crassicaudata in the Lesser Himalayas of Pakistan and informs targeted, context-specific conservation interventions.

Dromedary urinotherapy is a longstanding traditional practice in regions where camels are commonly reared, particularly for the management of metabolic disorders, cancer, and viral infections. Despite its ethnomedicinal relevance, the bioactivity of camel urine (CU) has been reported previously, though often without detailed characterization of the biological source. This study provides an exploratory, biologically contextualized evaluation of Moroccan CU using a set of well-documented samples collected under defined physiological and ecological conditions. Gas chromatography-mass spectrometry (GC-MS) analysis revealed a diverse metabolite composition, with major constituents including benzoic acid (61.48%), lactic acid (17.79%), p-cresol (19.84%), p-cresol glucuronide (14.94%), hippuric acid (11.97%), aminomalonic acid (7.48%), and phenylacetic acid (4.53%). Antioxidant assays demonstrated marked variability among samples, with higher activity observed in camels consuming desert vegetation rich in bioactive phytochemicals, suggesting an association with differences in diet and environmental conditions. Phage inhibition testing showed a significant reduction in bacteriophage titers at 200mg/mL in most samples, except GFS. Exploratory analysis suggested a possible association between p-cresol glucuronide abundance and phage inhibition performance. These findings provide exploratory biochemical insight into Moroccan CU and suggest that specific metabolites and dietary factors may contribute to variation in its measured bioactivities, warranting further investigation.

The Jingpo Lake lava plateau is a distinctive volcanic ecosystem with complex microtopography, low water retention, and severe nutrient deficiency, making it an ideal natural laboratory for investigating vegetation-soil-microbial interactions during ecological succession. Knowledge of soil-microbial stoichiometric coupling and nutrient limitation in volcanic landscapes remains limited. To address this gap, we investigated soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), microbial biomass (MBC, MBN, MBP), microbial entropy (qMBC, qMBN, qMBP), and stoichiometric imbalance (C:Nimb, C:Pimb, N:Pimb) across five vegetation types-grassland (GL), shrubland (SL), deciduous broad-leaved forest (DB), coniferous and broad-leaved mixed forest (CB), and coniferous forest (CF). The results showed that the soil TN and TP contents in SL were significantly higher than those in forest vegetation types (p < 0.05), likely attributable to its litter's low C:N ratio and low lignin content, which may facilitate accelerated N and P mineralization. Conversely, CF accumulated more SOC, potentially due to litter enriched in recalcitrant compounds exhibiting greater resistance to decomposition. Stoichiometric imbalance was pronounced in CB, which showed the lower qMBC but higher C:Nimb, C:Pimb, and N:Pimb values, indicating poor soil quality and reduced microbial growth efficiency. Redundancy analysis confirmed that C:Nimb and C:Pimb were the principal drivers of microbial entropy. Consistently high soil C:N and C:P ratios, together with low N:P ratios, indicate that vegetation growth on the lava plateau is primarily limited by nitrogen. These results provide empirical insights that may inform nutrient management and ecological restoration strategies in volcanic ecosystems.

This study conducted a genome-wide identification and functional analysis of the glutathione S-transferase (GST) gene family in the xerophytic desert shrub Reaumuria soongorica. A total of 67 GST genes were identified, classified into seven subfamilies, including Phi and Tau, with family expansion primarily attributed to small-scale duplication events. The findings revealed that ResoGST52, a member of the Tau subfamily, serves as a core gene in drought response, exhibiting significant upregulation of 2.40-fold in leaves and 9.01-fold in roots under drought stress. Mechanistic investigations indicated that the expression of ResoGST52 is likely directly regulated by the transcription factor ResoDof17, with specific hydrogen bonding interactions identified between the two. Co-expression network analysis further demonstrated that ResoGST52 cooperates with key pathways such as plant hormone signaling, MAPK cascades, and glutathione metabolism to collectively respond to drought stress. Notably, evolutionary analysis revealed that ResoGST52 has undergone positive selection, with three positively selected sites identified. Among these, the p.Ala115Ser mutation increases the volume of the protein's active site pocket, while the remaining mutations enhance surface hydrophobicity, thereby improving protein stability and catalytic efficiency under extreme drought conditions. In summary, this study not only systematically identifies the GST gene family in R. soongorica but also elucidates the central role of ResoGST52 in drought adaptation through multiple layers-from transcriptional regulation and co-expression networks to protein structural adaptive evolution-providing valuable candidate genes and theoretical insights for genetic improvement of drought tolerance in crops.

High-altitude arid regions are characterized by concurrent water scarcity, low temperatures, and intense solar radiation. However, the adaptive mechanisms of desert shrubs to these combined stressors remain poorly understood. To address this gap, we integrated large-scale field surveys with laboratory measurements of eight stem and leaf anatomical traits across six common desert shrub species in the Qaidam Basin. Principal component analysis (PCA) revealed two primary axes of trait variation. The first principal component (PC1) characterized a trade-off between leaf protective traits (e.g., cuticle and epidermal thickness) and stem hydraulic-storage traits (e.g., central cylinder, xylem, and pith diameters). The second principal component (PC2) was primarily loaded by stem cortex thickness, representing a physiological buffering mechanism. Based on PC1, species were categorized into two distinct strategic groups. Group A prioritized investment in stem conductive and storage tissues, enhancing hydraulic safety under hotter, high-evaporative demand conditions. Conversely, Group B exhibited reinforced leaf protective structures, consistent with tolerance to high radiation and low-temperature stress at higher elevations. The environmental gradients were the primary drivers of this divergence: Group A was associated with aridity, whereas Group B was correlated with elevation. Our findings demonstrate that desert shrubs in the Qaidam Basin have employed diverse adaptive strategies via the modulation of organ-specific anatomical traits to mitigate environmental stressors. These findings offer valuable insights into plant adaptive mechanisms, with implications for predicting vegetation responses and informing ecological restoration in high-altitude arid ecosystems.

Plant diversity plays a fundamental role in ecosystem functioning and is essential for sustaining ecosystem services. National forest inventories are key instruments for assessing floristic diversity. However, their measurement protocols may introduce bias by omitting smaller individuals because of the stem diameter criterion used or the minimum plant size threshold applied. Such bias is exacerbated in dryland ecosystems where small-statured plants with low-branching stems are particularly abundant. In this study, we evaluated the effects of using basal diameter (BD) instead of diameter at breast height, and of sampling small individuals (BD ≥ 2.5 cm), on the estimation of abundance, alpha and gamma diversity and community composition in different vegetation types in NW Mexico. We found substantial underestimation due to the omission of smaller individuals in xeric shrubland and tropical dry forest, where gamma diversity may be underestimated by up to 209% and 139%, respectively. Broadleaf forest also showed strong underestimation (133%), whereas mixed conifer–broadleaf forests were unaffected. We discuss these differential effects and propose a methodology to attenuate this underestimation and achieve more accurate floristic diversity estimates from national forest inventories in dryland vegetation, which encompasses roughly one-third of the Earth’s surface and more than half of Mexico’s territory.

Monitoring land cover dynamics and understanding vegetation responses to climate change are critical for ecological assessment and management in dryland regions. This study systematically analyzes land cover dynamics, vegetation type transitions, and their climatic drivers across Asian drylands from 2001 to 2022 by integrating MODIS land cover data, TerraClimate climate reanalysis datasets, and the Google Earth Engine (GEE) platform. Using a unified framework that combines land cover dynamic indices, transition probability and transfer matrix analyses, and climate attribution, we quantify spatiotemporal change patterns and identify dominant vegetation transition pathways. The results reveal pronounced land cover changes across Asian drylands over the past two decades, characterized by expansions of grasslands (GRA), savannas (SAV), croplands (CRO), and water, snow, and ice (WSI), alongside contractions of shrublands (SH), mixed forests (MF), permanent wetlands (WET), and barren land (BAR). Land cover transition analysis indicates that the most prominent conversion pathways are from barren land to grasslands and from grasslands to croplands, reflecting the combined influences of climate variability and land use processes. Climate attribution analyses further demonstrate that vegetation dynamics across different stability zones exhibit distinct responses to long-term climate trends, with increasing maximum temperature, soil moisture, and vapor-related variables, together with declining precipitation, drought indices, and surface radiation, jointly shaping vegetation persistence, expansion, or degradation. By integrating long-term multi-source datasets and cloud-based geospatial computing, this study provides a scalable and reproducible framework for assessing land cover change and vegetation stability in arid and semi-arid regions. The findings enhance understanding of dryland ecosystem dynamics under climate change and support large-scale ecological assessment in data-scarce environments.

In arid ecosystems, plant reproduction is strongly constrained by water availability, yet individuals within the same population can differ in reproductive output despite experiencing similar climatic conditions. Understanding how spatial variation in water availability translates into differences in growth and reproduction is essential for predicting population persistence under increasing aridity. We tested the hypothesis that spatial heterogeneity in soil water availability generates individual differences in cumulative water stress that influence physiological performance, growth, and flowering in Myrcianthes coquimbensis , an endangered shrub of the Atacama Desert. Over a 15-month period, we monitored soil water potential, predawn leaf water potential, photosynthesis, vegetative growth, and reproduction in a natural population, where individuals were classified based on recent reproductive history as annual-flowering or sporadic-flowering. Cumulative water stress during the growing season was quantified using the Water Stress Integral (WSI), which integrates the magnitude and duration of plant water deficit. Soil water availability was spatially heterogeneous, and this heterogeneity was reflected in consistent differences in plant water status among individuals. Although photosynthesis declined with decreasing plant water status in both reproductive groups, annual-flowering individuals maintained higher mean photosynthetic rates and experienced significantly lower WSI than sporadic-flowering plants. Higher WSI was associated with reduced relative growth rates and marginally lower annual growth. Flowering probability increased sharply as WSI became less negative and exceeded 50% at approximately −90 MPa, indicating a threshold-like relationship between cumulative stress and reproduction. These results show that spatial heterogeneity in soil water availability within a single population can generate individual differences in WSI that translate into nonlinear variation in growth and flowering. By integrating short-term physiological responses over time, WSI provides a mechanistic link between environmental variability and reproductive outcomes in dryland plants.

Soil salinization is one of the main stress factors limiting plant growth and ecosystem restoration in arid regions. Arbuscular mycorrhizal fungi (AMF) can form common mycorrhizal networks (CMNs) that potentially facilitate resource and signal exchange between plants. In this study, we investigated whether such processes associated with AMF connectivity might contribute to salt tolerance in different plant combinations, using Glycyrrhiza inflata and Lycium ruthenicum. However, under salt stress, it remains unclear how different plant combinations (conspecific vs. heterospecific) may differentially benefit from CMN-mediated processes under salt stress, and whether such processes involve coordinated stress signaling and nitrogen transfer. This study used Glycyrrhiza inflata (a leguminous N-fixing plant with a "N-input" strategy) and Lycium ruthenicum (a deep-rooted desert shrub with a "resource-use efficiency" strategy) as materials to construct conspecific and heterospecific plant combinations: G-G (G. inflata-G. inflata), L-L (L. ruthenicum-L. ruthenicum), G-L (G. inflata-L. ruthenicum), and L-G (L. ruthenicum-G. inflata). Four salt stress levels were set (NaCl concentrations of 0, 150, 250, and 350 mmol·L-1), along with AMF inoculation treatments. The study evaluated responses in AMF colonization, nitrogen transfer, biomass, root structure, photosynthetic characteristics, antioxidant capacity, osmotic regulation, and hormone levels. The results show that: (1) AMF colonization rates in all inoculated groups significantly decreased with increasing salt concentration, with the G-L combination showing a smaller decline; (2) The G-G combination maintained strong root activity and photosystem stability under high salt stress, exhibiting higher salt tolerance; (3) In conspecific combinations, the JA-Pro signaling pathway was dominant, whereas in heterospecific combinations, the ABA-SOD pathway prevailed, indicating differences in hormone regulation mechanisms among different combinations; (4) 15N transfer efficiency was significantly higher in conspecific combinations than in heterospecific combinations (p < 0.05), and increasing salt concentrations limited the resource-sharing ability of heterospecific combinations. In summary, our results revealed distinct physiological and hormonal responses in conspecific versus heterospecific plant combinations under salt stress when grown in an AMF-colonized system that permits hyphal connections. These patterns were consistent with a potential role of CMNs in signal coordination and resource sharing, although further experiments with disrupted hyphal connections would be required to confirm this mechanism.

Land use and land cover change (LULCC), predominantly driven by human endeavors such as urbanization and agricultural intensification, has become a significant global problem. The primary aim of this research was to evaluate the effects of LULCC on surface runoff in the Meki watershed. The Google Earth Engine platform’s Random Forest machine learning classifier was used to gather, process, validate, and analyze a variety of satellite photos in order to analyze the rate of LULC changes over four time references, beginning with 1990–2022. Before using the satellite images, preprocessing, classification, and accuracy assessment were performed sequentially. During the four periods from 1990 to 2022, the watershed’s six LULC classes, cultivated land, water, shrub land, grassland, forest, and bare land, were recognized. A significant rate change of LULC was observed in the watershed in each decade. Accordingly, the growth of agricultural land increased from 47.77 to 81.16%, followed by bare land 2.88% to 7.42%. In contrast, over the course of three decades, from 1990 to 2022, the percentages of forest cover, shrub land, and grassland declined sharply from 26.62 to 7.89%, 17.73% to 1.68, and 4.11% to 1.05%, respectively. In order to calculate surface runoff for the Meki watershed, the hydrological Soil and Water Assessment Tool (SWAT) model was set up and parameterized for flow and sediment load. Each LULC scenario’s model calibration and validation are carried out utilizing SWAT-CUP software’s SUFI-2. Model performance statistics, such as R2, NSE, RSR, and PBIAS, as well as model uncertainty metrics, such as p-factor and r-factor, were checked after the model was calibrated and validated. The mean annual surface runoff of the watershed is 117.15, 121.48, 133.93, and 158.84 mm. Accordingly, the Change in LULC from 1990 to 2001, 2001 to 2013, 2013 to 2022, and 1990 to 2022 resulted in an increment of 3.69%, 10.24%, 18.56%, and 35.58% in surface runoff, respectively.

Chenopodioideae plants are dominant components of desert ecosystems in arid regions of China and Central Asia and play key roles in maintaining ecosystem stability, while also providing valuable systems for understanding evolutionary and environmental adaptations of desert vegetation. However, at the family level, stoichiometric patterns across functional groups and plant organs in Chenopodioideae species remain poorly understood. We investigated 68 desert sites along a > 2000 km desert transect in northwestern China and collected leaf and stem samples from 39 Chenopodioideae species. After data preprocessing and standardization, 167 independent leaf units and 161 independent stem units were retained for subsequent analyses. We examined variation patterns and environmental drivers of nitrogen (N), phosphorus (P), and potassium (K) across functional groups (C3 vs. C4 plants; trees, shrubs, and herbs) and organs (stems and leaves) at the community level. Compared with global and national datasets, Chenopodioideae plants exhibited lower N concentrations (8.846 mg g− 1 in stems and 15.768 mg g− 1 in leaves) but higher P (1.235 mg g− 1 and 1.497 mg g− 1) and K concentrations (23.758 mg g− 1 and 27.656 mg g− 1), suggesting potential nitrogen limitation. Significant differences in nutrient concentrations were observed among most functional groups and organs. Based on community-weighted means, leaves exhibited consistently lower P-K scaling exponents than stems across functional groups, suggesting enhanced K-related stress resistance. Stem and leaf N, P, N: P, and P: K exhibited homeostatic or strictly homeostatic patterns, supporting the “Stability of Limiting Elements Hypothesis”. Nutrient traits showed divergent responses along latitude, longitude, and aridity gradients, reflecting diverse adaptive strategies. Environmental drivers varied among traits and organs. Soil, climatic, and geographical factors jointly regulated nutrient concentrations and ratios through interacting pathways, with soil factors generally exerting stronger relative influences. Overall, our findings reveal differentiated yet partially convergent stoichiometric strategies among functional groups and organs, highlighting adaptive nutrient regulation mechanisms in arid desert ecosystems.

Mixed shrub forests are superior in enriching desert vegetation diversity: evidence for an indirect pathway mediated by soil microorganisms

Soil fungi are pivotal drivers of biogeochemical cycling, mediating nutrient transformation, plant-soil feedbacks, and ecosystem stability. Understanding their responses to vegetation succession is essential for predicting ecosystem recovery in fragile volcanic landscapes. We investigated soil fungal communities across five successional stages on the Jingpo Lake lava plateau-grassland (GL), shrubland (SL), deciduous broad-leaved forest (DB), coniferous and broad-leaved mixed forest (CB), and coniferous forest (CF)-using high-throughput ITS sequencing and soil physicochemical analysis. Basidiomycota and Ascomycota dominated at the phylum level, with Sebacina, Cortinarius, and Mortierella as core genera. Alpha diversity (Shannon, Simpson, Chao1) was significantly higher in early-successional GL and SL than in DB (p < 0.05), while CB exhibited the lowest community evenness (Pielou-e). Co-occurrence networks revealed greater connectivity in GL, whereas forest types showed simplified topologies. LEfSe identified distinct fungal biomarkers for each vegetation type. PICRUSt2-based functional prediction indicated biosynthesis as the dominant pathway (>40%), with significant variation among vegetation types. Redundancy analysis (RDA) identified soil organic matter (SOM) as the primary predictor of fungal community composition. Our findings indicate that vegetation succession is associated with changes in fungal diversity and function primarily linked to variations in SOM, with moisture regimes as a secondary contextual factor. Notably, advanced forest stages exhibited reduced fungal diversity and simplified community structure-highlighting a trade-off between nutrient enrichment and microbial complexity in volcanic ecosystems. These insights advance our understanding of plant-soil-microbe coupling during ecosystem restoration on lava plateaus.

Soil salinization threatens productivity and ecosystem stability in arid regions, yet salinity-tolerance mechanisms of native UAE desert shrubs remain poorly resolved under field-like conditions. This study aimed to identify tolerance strategies and rank salinity resilience among Lycium shawii, Salvadora persica, Calligonum comosum, and Haloxylon salicornicum. Plants were grown in an outdoor pot trial under ambient desert conditions and irrigated with three salinity levels (ECw = 1.5, 10, and 25 dS m-¹). Severe salinity (25 dS m-¹) revealed clear interspecific divergence: S. persica and L. shawii maintained 100% survival, relatively stable water status and photosynthetic performance, and reduced membrane injury and lipid peroxidation. Their tolerance was associated with stronger osmotic adjustment (higher proline and soluble sugars), improved ion homeostasis (lower shoot Na+ accumulation and more stable K+ status relative to H. salicornicum), and enhanced antioxidant capacity (higher enzyme activities and radical scavenging). In contrast, C. comosum showed reduced survival (83.3%), marked dehydration, strong photosynthetic inhibition, weak antioxidant activation, and pronounced membrane damage, indicating limited high-salinity tolerance. H. salicornicum displayed intermediate performance, consistent with ion-handling-based tolerance but with higher physiological costs. Overall tolerance ranked S. persica > L. shawii > H. salicornicum > C. comosum. Correlation analysis and PCA supported coordinated contributions of water status, ion regulation, and oxidative protection to tolerance. These findings provide field-relevant mechanistic evidence to guide species selection for biosaline agriculture and saline-land rehabilitation in arid environments.

Primula himalayana sp. nov., a new species of Primulaceae, is described and illustrated from Tawang, Lutrem, 4238 m a.s.l., Arunachal Pradesh, India. It grows under Juniperus and Berberis scrub forest in an alpine meadow. The new species belong in Primula section Cordifoliae and is resembling P . gambeliana , but differs from the latter by the lamina puberulent with a white protuberance on the tips of the teeth, petiole 2‒3 times longer than lamina and white puberulent, scape long with many flowers, flowers yellow with orange‐yellow center and along corolla tube, corolla lobes elliptic, anther basifixed, and ovary cylindrical without any teeth.

Analyzing changes in land use and land cover (LULC) is crucial for ensuring long-term ecological sustainability. This study investigated the spatio-temporal dynamics of LULC, with a particular focus on irrigation expansion and its effects on ecosystem services in the Lake Tana sub-basin. An ensemble machine learning algorithm, random forest, was employed in the LULC classification for 1985, 2003, and 2021. The Normalized Vegetation Index (NDVI) was used to differentiate between rain-fed and irrigated lands, and the impact of LULC dynamics on Ecosystem Service Values (ESVs) was evaluated using modified valuation coefficients tailored to Ethiopian biome conditions. Based on the classified maps, the agricultural land increased significantly from 43.95 to 55.22%, and the irrigated agriculture rose from 1.24 to 8.69% between 1985 and 2021, whereas grassland and shrub land decreased from 14.38 to 5.35% and 18.85 to 15.34%, respectively, within the same periods. The largest gain was observed for irrigated agriculture, while the greatest loss was observed for grasslands over 36years. The total ESVs of the sub-basin were estimated at US$2.98 billion in 1985, US$2.96 billion in 2003, and US$2.995 billion in 2021. Over the 36years, approximately US$0.015 billion (0.52%) in ESVs was gained, highlighting the effects of LULC changes on ecosystem services. To mitigate these impacts, strategic land use planning should incorporate ecosystem service valuation into decision-making, reinforce regulatory frameworks, and advance sustainability initiatives. Future research should focus on enhancing classification accuracy by integrating higher-resolution satellite imagery, incorporating socio-economic variables, and simulating future ESV scenarios under various development pathways.

ABSTRACT Soil fungal diversity in the Neotropics remains poorly understood, despite growing evidence of high endemism and many undescribed taxa. Here, we analyzed the Global Soil Mycobiome dataset from 55 sites across the Mexican Neotropics, integrating community composition with alpha‐ and beta‐diversity metrics. Cluster and ordination analyses revealed eight distinct community groups largely explained by vegetation type and ecogeographic patterns. Tropical rainforests and temperate conifer forests harbored the highest richness (mean &gt; 1500 OTUs), whereas coastal dunes showed the lowest (&lt; 400 OTUs). Xeric shrublands, despite reduced richness, exhibited high evenness, suggesting niche differentiation under stressful conditions. Prevalence and indicator species analyses highlighted the role of ectomycorrhizal taxa in coniferous and coastal systems, soil saprotrophs in Pinus – Quercus forests, and plant pathogens in xeric shrublands, while many tropical lineages remained unclassified. Multivariate redundancy analysis identified pH, mean annual precipitation and elevation as the strongest independent drivers of fungal turnover, with soil nutrients (N, P, δ 15 N) explaining finer‐scale variation. Together, these results demonstrate that broad climatic gradients and vegetation types structure fungal communities in the northern Neotropics, while local soil properties refine community assembly. Our findings underscore the importance of tropical rainforests, temperate montane forests, and xeric shrublands as key reservoirs of soil fungal diversity, and provide a predictive framework for the conservation and monitoring of Neotropical ecosystems within initiatives such as the Soil Biodiversity Atlas of Mexico.

ABSTRACT Carbon dynamics are essential for understanding plant drought adaptation, yet how desert shrubs coordinate photosynthesis, growth, and storage under drought remains unclear. We quantified light‐saturated photosynthetic assimilation rate ( A sat ), leaf absolute growth rate (AGR), and whole‐plant non‐structural carbohydrates (NSCs) in two dominant desert shrubs, Haloxylon ammodendron and H. persicum , across a water‐stress gradient associated with groundwater depth, precipitation exclusion, and seasonal drying, using predawn leaf water potential (Ψ PD ) as an integrative index of plant water status. Furthermore, we evaluated linkages among Ψ PD , A sat , AGR, and NSCs. AGR declined faster than A sat as Ψ PD decreased, suggesting the photosynthesis–growth decoupling at the leaf level under increasing water stress. While whole‐plant NSCs remained stable, organ‐specific starch and soluble sugar patterns diverged between species: H. ammodendron accumulated starch in branches, whereas H. persicum increased leaf starch concentrations and decreased sugar:NSCs ratios, with opposite trends observed in the roots. Moreover, A sat was negatively correlated with branch starch concentrations in H. ammodendron , but negatively correlated with leaf starch concentrations in H. persicum . The relationships between AGR and branch starch concentrations tended to be negative in H. ammodendron , whereas leaf and root NSCs were negatively related to AGR in H. persicum . These findings suggest that aboveground organs adopt conservative carbon utilization strategies under drought, while belowground organs shift toward acquisitive strategies, highlighting contrasting carbon use patterns that may enhance drought survival in desert shrubs.

Grazing is a pervasive disturbance in arid and semi-arid grasslands that can influence plant reproduction through both direct tissue removal and indirect soil-mediated pathways. Because seed production and allocation strategies determine population persistence and vegetation recovery under chronic disturbance, understanding how grazing reshapes reproductive investment is critical, particularly for long-lived desert shrubs. We investigated how different grazing intensity reshapes growth-reproduction trade-offs and seed allocation strategies of the dominant desert shrub Reaumuria soongorica in a desert steppe of northern China. Using a long-term grazing experiment with no grazing (CK), moderate grazing (MG), and heavy grazing (HG) treatments, we quantified shrub growth, reproductive traits, soil properties, and fertile island effects beneath shrub canopies and interspaces area. Grazing intensity exerted contrasting effects on shrub performance. Moderate grazing enhanced shrub biomass, seed production, and female fitness, whereas heavy grazing significantly suppressed reproductive traits, including seed number and seed mass. Across treatments, grazing induced a clear shift in seed allocation, strengthening the seed number-seed mass trade-off under increasing disturbance. Structural equation modeling revealed that grazing affected reproductive allocation through both direct negative effects and indirect soil-mediated pathways. Grazing increased soil carbon, nitrogen, and phosphorus beneath shrubs while exerting minimal effects on interspace soils, indicating spatial redistribution of nutrients and intensified fertile island effects. Soil fertility promoted reproduction, whereas altered soil stoichiometric ratios constrained growth, highlighting opposing soil controls on shrub performance. We further identified reciprocal feedback between shrub functional traits and fertile island effects, whereby trait-driven resource accumulation and grazing-enhanced soil heterogeneity jointly regulated reproductive strategies. These results demonstrate that long-term grazing reorganizes soil-plant feedbacks and seed allocation trade-offs, providing mechanistic insights into shrub persistence and informing sustainable grazing management in arid grassland ecosystems.

Precipitation alters the microbial necromass carbon contribution to soil organic carbon in a desert shrub ecosystem