Leaf-level plasticity of Salix gordejevii in fixed dunes compared with lowlands in Hunshandake Sandland, North China.

To cope with adverse environments, the majority of indigenous plants in arid regions possess adaptive plasticity after long-term evolution. Leaf-level morphology, anatomy, biochemical properties, diurnal water potential and gas exchange of Salix gordejevii distributed in fixed dunes and lowlands in Hunshandake Sandland, China, were compared. Compared to plants growing in lowlands, individuals of S. gordejevii in fixed dunes displayed much smaller leaf area (0.26 vs 0.70 cm(2)) and thicker leaves (leaf total thickness 148.59 vs 123.44 mum), together with heavier crust wax, denser hairs, and more compacted epidermal cells. Moreover, those growing in fixed dunes displayed stronger drought-resistance properties as evidenced by higher levels of proline (3.68 vs 0.20 mg g(-1) DW) and soluble sugar (17.24 vs 14.49%). Furthermore, S. gordejevii in fixed dunes demonstrated lower water potential and lower light compensation point (28.8 vs 51.9 micromol m(-2) s(-1)). Our findings suggest that morphological and/or anatomical plasticity in leaves has had great adaptive value for Salix in responding to deteriorating environments. The evidence provided here may facilitate the prediction of plant adaptation in community succession in sandy habitats.