As the primary secondary tree species in Northeast China, Quercus mongolica possesses significant ecological and economic value. This study employed the Biomod2 platform in conjunction with ArcGIS spatial analysis to assess the potential suitable habitat distribution area of Q. mongolica under current climatic conditions. Furthermore, it forecasted the distribution range and niche changes of potentially suitable habitats for Q. mongolica from 2022 to 2090 and pinpointed the key environmental factors influencing its distribution. The findings reveal that the total potential suitable area for Q. mongolica covers 74,994.792 km², predominantly spread across Inner Mongolia, Heilongjiang, Jilin, and other regions. The primary determinants of suitable area distribution were peak temperature of hottest month, lowest temperature of coldest month, and altitude. Under future climate scenarios, the potentially suitable habitats of Q. mongolica are anticipated to diminish to varying extents, with the distribution center exhibiting a tendency towards northward migration. Concurrently, the overlap among different climate scenarios is predicted to expand over time. This investigation facilitates a comprehensive understanding of Q. mongolica’s adaptation to climate change, enabling informed adjustments and serving as a valuable reference for the preservation and sustainable management of Q. mongolica populations.

In ecological restoration of arid/semi-arid sandy lands, micro-topographic variations and artificial shrub arrangement synergistically drive vegetation recovery and soil quality improvement. As a typical fragile ecosystem in northern China, the Mu Us Sandy Land has long suffered wind erosion, desertification, soil infertility, and vegetation degradation, demanding precise vegetation configuration for ecological rehabilitation. This study analyzed soil nutrients, plant diversity, and their correlations under various micro-topographic conditions across different types of artificial shrub plantations in the Mu Us Sandy Land. Employing one-way and two-way ANOVA, we compared the significant differences in soil nutrients and plant diversity indices among different micro-topographic conditions and shrub species. Additionally, redundancy analysis (RDA) was conducted to explore the direct and indirect relationships between micro-topography, shrub species, soil nutrients, and plant diversity. The results show the following: 1. The interdune depressions have the highest plant diversity and optimal soil nutrients, with relatively suitable pH values; the windward slopes and slope tops, due to severe wind erosion, have poor soil nutrients, high pH values, and the lowest plant diversity. Both micro-topography and vegetation can significantly affect soil nutrients and plant diversity (p < 0.05), and vegetation has a greater impact on soil nutrients. 2. The correlation between surface soil nutrients and plant diversity is the strongest, and the correlation weakens with increasing soil depth; under different micro-topographic conditions, the influence of soil nutrients on plant diversity varies. 3. In sandy land ecological restoration, a “vegetation type + terrain matching” strategy should be implemented, combining the characteristics of micro-topography and the ecological functions of shrubs for precise configuration, such as planting Corethrodendron fruticosum on windward slopes and slope tops to rapidly replenish nutrients, promoting Salix psammophila and mixed plantation in interdune depressions and leeward slopes to accumulate organic matter, and prioritizing Amorpha fruticosa in areas requiring soil pH adjustment. This study provides a scientific basis and management insights for the ecological restoration and vegetation configuration of the Mu Us Sandy Land.

In the Mu Us Sandy Land, vegetation is closely related to soil microorganisms and nutrients. However, research on the relationship between soil microbial communities and nutrients in Pinus sylvestris var. mongolica plantations of different densities is still imperfect. This study selected Pinus sylvestris var. mongolica plantations with high, medium, and low densities, as well as bare sandy land, to analyze the relationship between vegetation density and soil nutrients, microbial community structure, and diversity indices. The results show that the following: (1) Medium-density plantations significantly increased soil organic matter, total nitrogen, and total potassium content, which were 4.3 times that of bare sandy land and 1.7 times that of high-density plantations; (2) In high-density plantations, the relative abundance of bacterial phyla Actinobacteriota and fungal phylum Ascomycota was higher; as plantation density decreased, the relative abundance of bacterial phyla Proteobacteria and Acidobacteriota and fungal phylum Basidiomycota increased, with different density plantations significantly affecting soil microbial community structure; (3) High-density plantations significantly increased the abundance of bacterial and fungal genera but also reduced bacterial diversity indices, while medium-density plantations were outstanding in enhancing fungal species richness and diversity, with the highest fungal Shannon index, indicating that medium density is conducive to fungal diversity enhancement; (4) Soil organic matter, total nitrogen, total phosphorus, total potassium, and pH value were the main environmental factors affecting soil microbial community structure. High-density plantations significantly affected soil microbial community structure by changing these soil nutrients and physicochemical properties, especially related to changes in total potassium and pH value. This study clarified the effects of Pinus sylvestris var. mongolica plantation density on soil nutrients and microbial community structure, revealing the intrinsic connection between soil nutrients and microbial communities, providing a theoretical basis for vegetation restoration in the Mu Us Sandy Land ecosystem, and helping to formulate scientific management strategies for Pinus sylvestris var. mongolica plantations to improve sandy land soil quality and promote the sustainable development of sandy land ecosystems.

Lycium ruthenicum Murr. (Black goji), a medicinal and economically valuable crop rich in bioactive compounds, remains genomically understudied despite its expanding cultivation. To overcome limitations of traditional markers in genetic diversity analysis and molecular breeding, we employed specific-locus amplified fragment sequencing (SLAF-seq) to develop genome-wide SNP markers and elucidate the genetic structure of 213 L. ruthenicum accessions from natural and cultivated populations in Alxa, China. We identified 827,630 SLAF tags and 33,121 high-quality SNPs uniformly distributed across 12 chromosomes, establishing the first high-density SNP database for this species. Population genetic analyses revealed three distinct genetic clusters with <60% geographic origin consistency, indicating weakened isolation due to anthropogenic germplasm exchange. The Qinghai Nuomuhong population exhibited the highest genetic diversity (Nei’s index = 0.253; Shannon’s index = 0.352), while low overall polymorphism (average PIC = 0.183) likely reflects SNP biallelic limitations and domestication bottlenecks. Notably, SNP-based clustering showed <40% concordance with phenotypic trait clustering (31 traits), underscoring environmental plasticity as a key driver of morphological variation. This study provides the first genome-wide SNP resource for L. ruthenicum, enabling marker-assisted breeding and highlighting the need for standardized germplasm management to mitigate genetic erosion.

Studying the biodiversity and multifunctionality relationships of the Hobq Desert shrub ecosystem and its response to environmental factors is crucial for ecological restoration in the region. In this study, we examined variations in biodiversity and ecosystem functioning along a precipitation gradient within the Hobq Desert shrub ecosystem. Using machine learning, we evaluated the predictive contributions of species richness and phylogenetic diversity to ecosystem multifunctionality (EMF) and applied structural equation modeling to analyze the direct and indirect impacts of biotic and environmental factors on multifunctionality. Our findings showed that species richness had a significant positive effect on EMF (p < 0.05), while phylogenetic diversity exhibited a relatively weaker influence, which was statistically non-significant (p = 0.257). Furthermore, species richness was identified as a stronger predictor of both individual ecosystem functions and EMF. Precipitation seasonality had a significant negative effect on EMF, indirectly influencing it through its impact on species richness. These findings highlight the essential role of species richness in maintaining ecosystem functioning within desert shrub ecosystems and emphasize the importance of effective biodiversity management, including both targeted conservation efforts and broad-scale ecological restoration, for preserving EMF under global climate change.

Sustainable forest management requires a comprehensive understanding of how stand density regulates soil ecological processes. We examined a Larix principis-rupprechtii plantation under three thinning retention densities (High—HD; Medium—MD; Low—LD) and an unthinned control (CK), with soil samples collected from four depth layers (0–10, 10–20, 20–30, and 30–40 cm). This study investigated the effects of stand density on soil properties and microbial communities in a Larix principis-rupprechtii plantation by combining high-throughput sequencing with soil physicochemical analysis to identify the optimal density regime for maintaining soil health. Results demonstrated the following: (1) Moderate-density (MD) management best balanced the stability of soil ecosystem structure, showing superior water retention, organic carbon content, and microbial diversity in the 0–30 cm soil layer. The mechanism underlying these improvements can be attributed to the moderately open canopy structure in MD stands, which facilitated efficient litter decomposition and drove functional complementarity between Basidiomycota (enhancing cellulose degradation capacity) and Acidobacteriota (adapted to oligotrophic conditions). (2) Redundancy analysis revealed that soil pH and available nutrients (AK, AP) were key environmental factors driving microbial community restructuring: Actinobacteriota dominated in neutral, phosphorus-rich environments, while Acidobacteriota thrived under acidic, phosphorus-limited conditions. Fungal communities showed high sensitivity to management intensity, with significant shifts between Ascomycota and Basidiomycota, whereas bacterial communities remained relatively stable due to functional redundancy. We recommend the adoption of moderate-density management as a sustainable practice to enhance soil nutrient cycling and maintain microbial diversity, thereby providing scientific support for sustainable plantation management.