Sequencing data of bacterial and fungal communities in soils under saline-alkali stress in four types of agricultural and pastoral habitats
Microorganisms regulate nutrient cycling and ecosystem stability in saline-alkali ecosystems, yet their adaptation mechanisms and metabolic functions under saline-alkali stress in agro-pastoral ecotones remain unclear. In this study, four typical saline-alkali habitats in the agro-pastoral ecotone of the Loess Plateau (saline-alkali flat, natural grassland, maize cropland, and shrubland) were selected. Bacterial and fungal communities were characterized via Illumina MiSeq sequencing to analyze community composition, diversity, co-occurrence networks, and functional traits, combined with Mantel tests, redundancy analysis, and partial least squares path modeling (PLS-PM) to identify environmental drivers. Results showed that saline-alkali stress significantly altered soil physicochemical properties. Bacterial communities were more sensitive to stress, exhibiting simplified co-occurrence networks and intensified interspecific competition, whereas fungal networks maintained high modularity and were dominated by positive correlations, reflecting a synergistic coexistence pattern. The stress inhibited bacterial chemoheterotrophy and nitrification but promoted fermentation and nitrate reduction. pH, available phosphorus, and soil organic carbon were key drivers. This study reveals the adaptive strategies and functional differentiation of bacterial and fungal communities under saline-alkali stress, providing a scientific basis for sustainable management and ecological restoration of saline-alkali lands in agro-pastoral ecotones.