Background <p>To understand whole-plant adaptation to variable environments, clarifying intraspecific variation and covariation of leaf and root traits is critical. Hydraulic traits coregulate above- and below-ground resource acquisition by the coordinated relationships between leaf and root traits, yet research on how hydraulic traits synergize with intraspecific leaf-root traits to construct the whole-plant economic space remains scarce.</p> Methods <p>We measured 15 leaf, root and hydraulic traits of <i>Dasiphora fruticosa</i> across shady and sunny slopes in alpine meadows, exploring intraspecific trait variation across habitats gradient, and the role of hydraulic traits in integrating above- and below-ground functions into a multidimensional whole-plant trait space.</p> Results <p>At the intraspecific level, both leaf and absorptive root traits exhibited multidimensional covariation but were significantly decoupled from each other: along the soil nutrient gradient from sunny, nutrient-poor slopes to shady, nutrient-rich slopes, leaf strategy shifted from conservative to acquisitive, whereas root strategy showed the opposite trend. Hydraulic traits functioned as core hub integrating above- and belowground dimensions. Specifically, hydraulic efficiency traits were associated with leaf resource acquisition and root foraging dimensions, while hydraulic safety traits (e.g., wood density) were linked to the root conservation dimension and leaf hydraulic safety.</p> Conclusions <p>This study provides new insights into intraspecific trait variation across environmental gradients, revealing that leaf-root dimension are integrated by hydraulic hub traits. It highlights the synergy between hydraulic efficiency traits and leaf-root acquisition-foraging and safety traits in coordinating root conservation and leaf hydraulic safety, and providing clues for exploring plant intraspecific adaptation strategies.</p>