Variations in Leaf Functional Traits of <i>Pseudotsuga sinensis</i> Across Forests With Varying Levels of Rocky Desertification

<i>Pseudotsuga sinensis</i> is a distinctive plant species endemic to China, predominantly found in areas affected by varying degrees of rocky desertification. Despite its wide distribution, the physiological mechanisms underlying its adaptation to harsh environments remain unclear. In this study, we investigated 16 leaf traits, including the morphological, anatomical, and chemical characteristics of the leaves of <i>P. sinensis</i> across forests with mild, moderate, severe, and extremely severe rocky desertification to elucidate the adaptive strategies of <i>P. sinensis</i> in response to arid conditions and nutrient-poor soils. Our findings revealed that <i>P. sinensis</i> leaves from forests with mild and moderate rocky desertification exhibited higher specific leaf area (SLA) and magnesium concentrations but lower leaf dry matter content (LDMC), abaxial epidermis thickness, and adaxial epidermis thickness than in those from forests with severe and extremely severe desertification. Principal component analysis indicated that forests with mild to moderate desertification employ resource acquisition strategies characterized by greater SLA and magnesium concentrations than those in forests with severe and extremely severe desertification. In contrast, forests with severe to extremely severe desertification adopted resource-conserving strategies, as evidenced by higher LDMC, epidermal thickness, and calcium concentrations than those in forests with mild to moderate desertification. The N:P ratio of <i>P. sinensis</i> across all desertification levels was consistently below 14, suggesting nitrogen limitation in <i>P. sinensis</i> in regions with rocky desertification. Thus, these results provide valuable reference for guiding vegetation restoration under degraded habitats.