Abstract: Leaf traits, the results of long-term interactions between plants and environment, are extremely sensitive to the surroundings in the process of evolution and influence the plants’ ‘costbenefit’ relationship. We investigated the leaf traits of Sassafras tsumu (Hemsl.) Hemsl. along an altitudinal gradient in the Tianmushan Mountain. Leaf morphological traits of S. tsumu, including leaf area, the ratio of leaf length to width, leaf dry weight and specific leaf area, were analyzed. Similarly, leaf physiological traits, including chlorophyll concentration and leaf nitrogen content (N_area), were analyzed. The results indicated that a significant difference existed in leaf area, and extremely notable differences existed in specific leaf area, the ratio of length to width and dry weight among subpopulations along the altitudinal gradient. Additionally, the coefficients of variation of dry weight and the ratio of lengthwidth within populations was less than those of leaf area and specific leaf area, which illustrated that leaf morphological traits exhibited different variations among subpopulations. Moreover, specific leaf area had significant positive correlations with leaf area and the ratio of length to width, while it had a significant negative correlation with leaf dry weight. Chlorophyll concentration showed a significant positive correlation with N_area. The linear regression relationship between the leaf characteristics and temperature demonstrated that leaf area, specific leaf area, chlorophyll concentration and N_area decreased as temperature dropped. On the contrary, dry weight and the ratio of length to width gradually increased.

Key words: faba bean, single cropping late rice, nutrient uptake, yield, nutrient use efficiency.