Background and aimsPlants adjust the trade-off relationships of plant functional traits (PFTs) and adopt different adaptation strategies to cope with the habitat heterogeneity at different stages of the karst desertification (KD) process. However, it is currently unclear how the habitat heterogeneity in desertification areas of North China Karst modulates the shifts in the interaction relationships among PFTs and the corresponding shifts in ecological strategies.MethodsWe constructed plant trait networks (PTN) of dominant species across different KD grade gradient in typical small watersheds of North China Karst. We used PTN parameter analysis and robustness analysis to elucidate structural shifts in PTN, and we used random forest models to reveal key habitat factors.Results(1) As KD grade increases, the PTN exhibits characteristics of decreased edge density and average clustering coefficient, increased average path length, diameter and modularity, concomitant with decreased network stability. This indicates that the synergy among trait nodes deteriorated, and they tended to form functional modules to perform specific functions. (2) In the PTN, the high-contribution trait nodes and functional modules related to resource acquisition efficiency gradually decreased, while those related to resisting drought resistance gradually increased. (3) The KD factors (PER, ST, VFC) and soil factors (AN, SOC, URE, TN) constitute the key habitat factors that modulate structural shifts in PTN.ConclusionsDuring KD process, habitat heterogeneity modulates the PTN structure and drives the evolution of plant ecological strategies from efficient resource acquisition to stress resistance.