Shijie Lv

Spatially explicit information on morphological variation within natural Haloxylon ammodendron populations remains limited. We examined size‐associated morphological and spatial variation in a natural population on the eastern margin of the Badain Jaran Desert. Plant height, crown diameter, and stem‐base diameter were measured for 1,151 individuals. Based on the lower and upper quartiles of stem‐base diameter, individuals were classified into small, intermediate, and large stem‐base diameter classes. Descriptive statistics and geostatistical analyses were used to characterize morphological variation and model spatial dependence. Mean plant height and crown diameter increased across the small, intermediate, and large stem‐base diameter classes. The interpolated maps showed spatial variation in all measured traits. Plant height and crown diameter exhibited partially similar spatial patterns, whereas stem‐base diameter showed a different spatial pattern. The fitted semivariogram parameters also differed among traits and diameter classes. The observed differences represent size‐associated morphological and spatial variation rather than independently validated age‐dependent changes. Because soil moisture, groundwater depth, local topography, wind fields, and plant interactions were not directly measured, the environmental mechanisms underlying the observed patterns remain unresolved.

How long-term grazing alters plant diversity and community composition across spatial scales in desert steppes remains poorly understood. We used a long-term grazing experiment established in 2004 in the desert steppe of Inner Mongolia, China, with four stocking-rate treatments: no grazing (CK), light grazing (LG), moderate grazing (MG) and heavy grazing (HG). We quantified α-diversity at quadrat, plot and treatment scales and evaluated compositional change using turnover–nestedness partitioning of β-diversity together with total β-diversity (BDTotal), local contributions to β-diversity (LCBD) and species contributions to β-diversity (SCBD). α-Diversity responses were scale dependent: species richness did not differ among treatments at the quadrat scale, whereas the Shannon–Wiener index, Simpson index and Pielou evenness declined mainly under HG; at broader scales, differences in species richness and the Shannon–Wiener index between CK/LG and MG/HG were more consistent. Increasing stocking rate reduced total β-diversity primarily through decreased species turnover, while the absolute nestedness-resultant component remained unchanged despite a higher relative contribution. Species-combination richness declined from 58 and 44 under CK and LG to 18 and 20 under MG and HG. BDTotal showed a consistent CK > LG > MG/HG pattern, and SCBD shifted from diffuse contributions by many species toward concentration in a few species under higher stocking rates. Overall, sustained increases in stocking rate promoted scale-dependent diversity loss and community convergence by weakening species replacement and concentrating the species-level sources of residual compositional differentiation. Maintaining species turnover and spatial compositional heterogeneity should therefore be a priority in desert-steppe grazing management.

Against the backdrop of global climate change, altered precipitation patterns profoundly affect grassland ecosystems in arid and semi-arid regions. To clarify the spatiotemporal heterogeneity in the relationship between long-term precipitation variation and vegetation response, this study focuses on East Ujimqin Banner, Inner Mongolia. Utilizing 35 years of precipitation monitoring data (1983-2017) and field vegetation survey data from four key years (1983, 2009, 2013, 2017), nine Sums (townships) were categorized into three regions: northeast, central, and southwest. Methods including linear regression and ANOVA were employed to systematically analyze the long-term trends in precipitation and their relationships with the productivity and dominance of Stipa species, as well as community species richness. The results indicate that: (1) The long-term precipitation trend exhibited spatial heterogeneity, with more pronounced interannual fluctuations and a higher rate of change in the northeastern and southwestern regions compared to the central region; (2) Vegetation sensitivity to precipitation change displayed a pattern of higher responsiveness in the periphery and lower in the central region, as the response slopes of Stipa fresh weight, importance value index, and total community fresh weight per unit precipitation change were significantly greater in the northeastern and southwestern areas than in the central area. (3) Stipa populations showed a tendency to shift from the northeastern and southwestern regions toward the central area. Concurrently, species richness increased in the peripheral regions as Stipa declined, while it temporarily decreased in the central region. This study reveals the specific process of spatial range shifts in dominant grassland species and the reshaping of community structure driven by climate change, elucidating the regional differentiation in ecological sensitivity. It provides an important scientific basis for adaptive grassland management and biodiversity conservation in the region.

To investigate the state transition processes of plant community in desert steppe under different stocking rates, this study aims to systematically uncover

To elucidate the driving mechanisms behind plant community state transitions in desert steppe under grazing disturbance, this study established a long-term monitoring platform (initiated in 2004) in Stipa breviflora desert steppe in Inner Mongolia. Four stocking rate gradients were implemented: no grazing (CK), light grazing (LG), moderate grazing (MG), and heavy grazing (HG), ranging from 0 to 2.71 sheep units·hm⁻²·half-year⁻¹. Plant population characteristics were surveyed across 145 quadrats. Using mean occurrence probability combined with transition probability models, this research quantifies the patterns and characteristics of mutual transitions at three levels—species, functional groups, and plant families—during state shifts induced by varying stocking rates. Results demonstrated that: As stocking rate increased, the species network shifted from a single-core hierarchy (dominated by Stipa breviflora) to a multi-core complex network, eventually simplifying into a sparse network governed by grazing-tolerant species under heavy grazing. Perennial grasses (PG) exhibited the highest grazing tolerance, receiving up to 43% of transition probability from other functional groups. Shrubs and semi-shrubs (SS) maintained system functionality through self-sacrifice (27% transition probability to PG during the MG stage), while annual-biennial plants (AB) acted as ecological bridges during state transitions. Poaceae (POA) consistently received resources (probability of OTH→POA increased to 52%), reinforcing its dominance, whereas resource transfer from Fabaceae (FAB) to POA (24%) intensified nitrogen limitation and triggered system state transition. In summary, a stocking rate≤1.82 sheep units·hm⁻²·half-year⁻¹ maintains multistability in S. breviflora desert steppe. Species, functional groups, and plant families revealed distinct response strategies during state transitions, whose salient manifestations and synergistic interactions provide a theoretical basis for adaptive management in desert steppes.

Herbivore grazing plays a crucial role in grassland ecosystems, yet its comprehensive impact on plant and soil nematode diversity in desert steppe remains unclear. We assessed the impact of different grazing intensities (CK: no grazing, LG: light grazing, MG: moderate grazing, HG: heavy grazing, EG: extreme heavy grazing) on plant and soil nematode diversity in desert steppe. In the HG treatment, the diversity of plants and nematodes was the lowest and significantly lower than that in the CK treatment. Compared with CK, the Sobs, Shannon‐Wiener, Inverse Simpson index, and Heip index of the plant community under HG decreased significantly by 23.78%, 37.97%, 47.43%, and 41.51%, respectively (p < 0.05). Simultaneously, the diversity indices of soil nematodes under HG also decreased significantly, being 22.2%, 40.3%, 50.9%, and 47.1% lower than those of CK, respectively. Linear and non‐linear correlation analyses demonstrated a significant positive correlation between plant diversity and nematode diversity, indicating a synergistic relationship between plant communities and soil nematode communities. Pearson correlation analysis revealed that Cleistogenes songorica (Roshev.) Ohwi and Stipa breviflora Griseb. were significantly positively correlated with the herbivorous nematode genus Paratylenchus (p < 0.05), while Convolvulus ammannii Desr. was significantly positively correlated with the genus Acrobeloides (p < 0.05). These results indicated that certain specific plant species exert significant regulatory effects on specific soil nematode species. Overall, heavy grazing is detrimental to the sustainable development of grasslands. Therefore, in light of previous research in this field, maintaining grazing intensity below the level of heavy grazing (LG or MG) is the most appropriate grassland management strategy.

Overgrazing is a key driver of degradation in Inner Mongolia’s desert steppe, where high stocking rates exacerbate wind erosion, thereby compromising ecosystem stability. This study examined Stipa breviflora desert steppe under four stocking rate gradients (0, 0.91, 1.82, and 2.71 sheep·hm ^-2 ·year ^-1 ), analyzing total nitrogen (TN), total phosphorus (TP), and N:P ratios in soil (0–30 cm depth), aeolian sediment (0–30 cm above ground), and plant communities to assess their homeostatic responses. The conclusions as follows: (1) Grazing significantly reduced plant TN and TP ( P < 0.05) while increasing plant N:P, whereas soil exhibited the opposite trend—TP decreased and TN accumulated, elevating soil N:P; (2) Homeostatic regulation varied with grazing intensity—under light grazing (LG), plant TP homeostasis stabilized (H = 4.84), while moderate grazing (MG) prioritized TN homeostasis (H = 20.37); heavy grazing (HG) only partially maintained homeostasis via N:P adjustment; (3) Aeolian sediment nutrient dynamics significantly influenced plant homeostasis ( P -2 ·year ^-1 , vegetation loss impaired windbreak function, and grazing-wind erosion synergy pushed the system into a ”non-homeostatic” state. This study validates the ”grazing-wind erosion synergy” theory, highlighting the need for state-dependent management (homeostatic vs. non-homeostatic): LG and MG allows wind-driven nutrient redistribution, whereas HG requires strict control to prevent irreversible degradation.

In agro-pastoral transitional zones, monitoring vegetation fraction coverage (FVC) and understanding its relationship with land use and climate change are crucial for comprehending how complex land-use/land-cover change (LUCC) improves ecological restoration and land management. This study focuses on the agro-pastoral transitional zone of Inner Mongolia, aiming to analyze vegetation cover changes from 2000 to 2020 using the Mann–Kendall (MK) significance test, Theil–Sen median trend analysis, and coefficient of variation (CV) analysis. Additionally, the study explores the impacts of LUCC, precipitation, and temperature on vegetation cover using methods such as geo-detector, pixel-based statistical analysis, and univariate linear regression. Based on the PLUS land-use prediction model and linear regression results, vegetation cover was simulated under different land-use scenarios for the future. The main findings are as follows: first, from 2000 to 2020, the spatial distribution of vegetation cover in the study area showed a distinct pattern of higher vegetation cover in the east compared to the west, with significant spatiotemporal heterogeneity. Although the overall vegetation cover slightly increased, there were notable differences in the trend across regions, with some areas experiencing a decrease in FVC. Second, LUCC is the most significant explanatory factor for vegetation cover changes, and the interactions between LUCC and other factors have a particularly notable impact on vegetation cover. Third, scenario simulations based on the PLUS model indicate that, by 2040, vegetation cover will perform optimally under the farmland protection and sustainable development scenarios. Particularly under the farmland protection scenario, the conversion of cropland, forestland, and grassland is notably suppressed. In contrast, the unmanaged natural development scenario will lead to a decline in vegetation cover. The results of this study show that vegetation cover in the agro-pastoral transitional zone of Inner Mongolia exhibits substantial fluctuations due to land-use change. Future ecological restoration policies should incorporate land-use optimization to promote vegetation recovery and address ecological degradation.

Due to climate change and global warming, the frequency of sandstorms in northern China is increasing. Stipa breviflora, a dominant species in Eurasian grasslands, can help prevent desertification from becoming more serious. Studies on S. breviflora cover a wide range of fields. To the best of our knowledge, the present study is the first to sequence, assemble, and annotate the S. breviflora genome. In total, 2,781,544 contigs were assembled, and 2,600,873 scaffolds were obtained, resulting in a total length of 649,849,683 bp. The number of scaffolds greater than 1 kb was 70,770. We annotated the assembled genome (>121 kb), conducted a selective sweep analysis, and ultimately succeeded in assembling the Matk gene of S. breviflora. More importantly, our research identified 26 scaffolds that may be responsible for the drought tolerance of S. breviflora Griseb. In summary, the data obtained regarding S. breviflora will be of great significance for future research.