As one of the most prominent gene families, R2R3-MYB transcription factors significantly regulate biochemical and physiological processes under salt stress. However, in Sophora alopecuroides, a perennial herb known for its exceptional saline alkali resistance, the comprehensive identification and characterization of SaR2R3-MYB genes and their potential functions in response to salt stress have yet to be determined. We investigated the expression profiles and biological functions of SaR2R3-MYB transcription factors in response to salt stress, utilizing a transcriptome-wide mining method. Our analysis identified 28 SaR2R3-MYB transcription factors, all sharing a highly conserved R2R3 domain, which were further divided into 28 subgroups through phylogenetic analysis. Some SaR2R3-MYB transcription factors showed induction under salt stress, with SaR2R3-MYB15 emerging as a potential regulator based on analysis of the protein–protein interaction network. Validation revealed the transcriptional activity and nuclear localization of SaR2R3-MYB15. Remarkably, overexpression of SaR2R3-MYB15 in transgenic plants could increase the activity of antioxidant enzymes and the accumulation of proline but decrease the content of malondialdehyde (MDA), compared with wild-type plants. Moreover, several salt stress-related genes showed higher expression levels in transgenic plants, implying their potential to enhance salt tolerance. Our findings shed light on the role of SaR2R3-MYB genes in salt tolerance in S. alopecuroides.

In arid sandy plantations, stand density critically regulates belowground ecosystems, yet its effects on microbial network complexity, stability, and function are not fully understood. This study examined Pinus sylvestris var. mongholica plantations along a density gradient (Very high density (VHD): 2,450 trees ha ⁻¹ , High density (HD): 1,633 trees ha ⁻¹ , Moderate density (MD): 1,067 trees ha ⁻¹ , Low density (LD): 583 trees ha ⁻¹ ) at two soil depths (0–20, 20–40 cm) in the Otingdag Sandy Land, integrating soil physicochemical, enzymatic, and microbial network analyses. Key findings were: (1) Soil organic carbon, total nitrogen, key enzyme activities [urease (URE), acid phosphatase (PHO), and nitrate reductase (NR)], and ecosystem multifunctionality showed a unimodal response, peaking at medium densities. (2) Microbial responses diverged: bacterial α-diversity changed but composition remained stable, whereas fungal composition was highly density-sensitive. Mid- to low densities promoted more complex, modular, and stable microbial networks. Mantel tests identified pH, URE, and Ammonium nitrogen (NH₄ ⁺ -N, AN) as key drivers for bacterial phyla, and pH, Soil organic carbon (SOC), Total nitrogen (TN), PHO, and Polyphenol oxidase (PPO) for differentiating Ascomycota and Basidiomycota. (3) Random Forest regression identified microbial network stability as the top predictor of multifunctionality, surpassing diversity. Partial Least Squares Path Modeling (PLS-PM) analysis revealed that stand density enhances multifunctionality primarily by improving the soil environment, with microbial networks acting as environment-dependent regulators. This study demonstrates that moderate stand densities optimize microbial network resilience and ecosystem multifunctionality in sandy plantations, providing a novel perspective from microbial network stability.

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.

Sustainable forest management requires a comprehensive understanding of how stand density regulates soil ecological processes. 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 that 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). 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.

Anthropogenic fires in agro-pastoral ecotones are understudied. Using Ordos data (1987–2020) and machine learning, we identified fire drivers and patterns. Fires clustered in eastern populated areas, increased after 2000, and peaked recently, with April seasonality. Human-related ignitions dominated. Slope, humidity, and precipitation consistently drove burned area. Fires shifted to lower, drier, cooler conditions, suggesting possible advancing fire season and increasing human influence. Ecological restoration has been associated with increased fuel continuity, and the temporal coincidence suggests a potential restoration–fire paradox, although this hypothesis requires direct testing. Management should prioritize spring vigilance and fuel integration; better data on human behavior and fine fuels are needed for early warning.