Climate-groundwater interactions are the dominant drivers of plant-environment feedback processes in drylands worldwide. However, the responses of dryland ecosystems to acute atmospheric drought and chronic groundwater decline, as well as the underlying feedback loops that control state stability or transition of such ecosystems across different soil properties and plant salt tolerance remain uncertain. To address this knowledge gap, we introduces a comprehensive methodology that integrates a minimalist stochastic species-dependent soil water-salt dynamics model, a novel plant salinity-dependent water stress model, and a robust modelling framework for water and salt stress-vegetation feedbacks. Using lysimeter experiments and field transect studies, these models were showcased in the salt-tolerant Haloxylon ammodendron (H. ammodendron) ecosystem with fine-textured soils and salt-sensitive Haloxylon persicum (H. persicum) ecosystem with coarse-textured soils in the Gurbantunggut Desert, China. Our results indicate that over time water-salt imbalances are becoming more pronounced, driven by shifting precipitation regimes, declining groundwater tables, depleting soil moisture and intensifying salinization. The enhanced feedback between changing water and salt regimes and vegetation is forcing both Haloxylon ecosystems into a new stable state (i.e., bare or sparsely vegetated land), with shift in water-salt stress of the component species contributing to this transition. Furthermore, the tradeoff between resistance and resilience of such ecosystems is declining from the desert margins to the desert hinterlands. The H. ammodendron ecosystem shows lower resistance and resilience (indicating a decrease in stability), while the H. persicum ecosystem exhibits higher resistance and resilience. Although the water and salt stress-vegetation feedback in both Haloxylon ecosystems is driven by atmospheric and groundwater conditions and mediated by plant salt tolerance, their changing condition is ultimately determined by soil properties. These findings have major implications for the conservation and restoration of similar dryland ecosystems worldwide, especially in the context of a changing climate.