Abstract: There are some sandy hills distributed along Poyang Lake, which belong to typical southern desertification. As located in subtropical climate zone, the sandy hills differed in vegetation and soil from northern deserts. In this study, leaves of Vitex rotundifolia were sampled along desertification intensity gradient in Duobao sandy hill, Poyang Lake. Subsequently, leaf area, specific leaf area (SLA), leaf nitrogen (N) and phosphorus (P) were measured. The objective of this study was to clarify the intraspecific variation in leaf traits and the responses to desertification intensity variation. Results indicated that leaf area of V. rotundifolia ranged from 1.58 to 13.14 cm². No significant correlation was found between leaf area and the distance away from lakeshore line. Thus, leaf area could not indicate the effects of desertification intensity on V. rotundifolia. SLA varied from 81.6 to 206.3 cm²·g^-1. SLA showed significant intraspecific difference (P<0.05). Leaf N ranged from 16.0 to 23.2 mg·g^-1, whereas leaf P varied from 0.82 to 2.20 mg·g^-1. Both leaf N and P showed no significant intraspecific difference. SLA was significantly positively correlated with leaf N, but not with leaf P. SLA was very sensitive to desertification intensity variation, and decreased with the increase of desertification. However, leaf N and P, as well as N:P stoichiometry were not sensitive to the desertification variation, and maintained relatively stable. According to the ratio of leaf N:P, V. rotundifolia was more limited by phosphorus, rather than nitrogen.

Key words: Poyang Lake, sandy hills, Vitex rotundifolia, specific leaf area, leaf nitrogen, leaf phosphorus