[Objective] To investigate the effects of different underlying surface types (desert and Gobi) along arid-region railway corridors on vegetation growth characteristics, water dynamics, and ecological adaptation mechanisms, thereby providing a scientific basis for vegetation configuration and water resource management in railway ecological zones. [Methods] Based on continuous monitoring from April to October 2023 at three representative sites along the Hotan-Ruoqiang Railway (DK48, DK258, and DK553), key indicators such as plant height, basal diameter, density, live coverage ratio, stemflow rate, and soil moisture were collected. Regression analysis and multivariate statistical methods were used to quantitatively explore the relationships between vegetation morphology and water-related factors. [Results] Vegetation in the desert area (DK258) exhibited significantly greater plant height (up to 192.85 cm), basal diameter (36.36 mm), and live coverage ratio (0.965) compared to the Gobi areas (DK48 and DK553), indicating stronger water acquisition capacity and ecological adaptability. Stemflow monitoring showed that Haloxylon ammodendron responded rapidly to spring precipitation (peaking from April to June at a rate of 5.61E-04 g/s), while Elaeagnus angustifolia exhibited increased stemflow in late summer, and Populus euphratica had relatively low but delayed stemflow peaks, with an annual water demand of 17.5 kg-substantially higher than Haloxylon (0.24kg) and Elaeagnus (0.44kg). Soil moisture analysis revealed that while the desert area has high infiltration but low water retention, the Gobi area suffers from strong evapotranspiration and limited infiltration, both leading to unfavorable moisture conditions for vegetation recovery. Regression models showed that Haloxylon height followed a quadratic growth pattern over time (R2=0.97), and canopy width expanded exponentially (R2=0.82), with precipitation (P) and soil moisture (M) as the primary driving factors. [Conclusion] Underlying surface types significantly influence vegetation morphology and water adaptation strategies. Desert zones are more suitable for deep-rooted species, while Gobi areas require water-saving interventions to improve soil moisture retention. It is recommended that ecological restoration projects adopt functional zoning and stratified planting strategies, with scientifically selected species and optimized irrigation regimes, to build an efficient, stable, and sustainable ecological protection system along arid-region railways.