Changing environments can alter plant functional traits in agricultural ecosystems, leading to shifts in plant resource utilization strategies. The plant trait network can integrate economic, hydraulic, and anatomical traits to reflect plants’ adaptation and responses to environmental changes from multiple perspectives. This study quantitatively analyzed the economic and hydraulic traits of leaves and roots in three cotton varieties under changing environments with different CO ₂ concentrations and water or salt stress, exploring the impact of changing environments on plant functional traits and resource utilization strategies. The results showed that under water or salt stress, the leaf economic spectrum (LES) exhibited a conservative strategy, while the root economic spectrum (RES) displayed an acquisitive strategy. Under elevated CO ₂ concentration, LES, RES, and hydraulic traits of both leaf and root showed conservative strategies. Additionally, under changing environments, the trade-off between LES and leaf hydraulic traits demonstrates a congruent resource utilization pattern, whereas the trade-off between RES and root hydraulic traits demonstrates an inverse pattern. We also found that changing environments altered the centrality of the plant traits network. Overall, the multi-faceted study of plant functional traits and their interrelationships provides a crucial basis for understanding the response of crops in agroecosystems to environmental changes.