Desert Plant Trait Networks Differ Among Plant Life Forms and Soil Moisture–Salinity Environments

Understanding the relationships among plant functional traits and how these are shaped by the soil environment is essential for the study of plant adaptation. Conducted in the desert ecosystem surrounding Ebinur Lake, China, this study assessed key functional traits for eight common desert plant species, including the foliar carbon (C), nitrogen (N), and phosphorus (P) content, and their stoichiometric ratios (C:N, C:P, N:P), as well as the chlorophyll content (Chl), leaf area (LA), and leaf thickness (LT). Separate plant trait networks (PTNs) were constructed for herbs, shrubs, and trees growing in two distinct soil environments: those with high (HS) versus low (LS) soil moisture and salinity. The study had three key findings. (1) Both soil properties and plant functional traits differed between HS and LS environments (p < 0.05). (2) Distinct PTNs were observed among plant life forms, with different central traits. Herbs (central traits: leaf thickness and the N:P ratio) had high-density PTNs demonstrating strong adaptability, while shrubs (central traits: C and P) and PTNs had high connectivity that was stable across soil environments; tree PTNs (central traits: N and the C:P ratio) were highly modular and showed strong resistance to disturbance. (3) Soil factors also regulated PTN topology, with the total nitrogen (TN) and total phosphorus (TP) being key regulators in HS, while the soil salt content and water content were the most important factors in LS. In conclusion, the PTNs of desert plants reflected their unique adaptations to arid environments, and the application of these findings should support efforts to conserve and manage desert vegetation.