Abstract: To understand the responses of leaf traits of Potentilla nivea to altitude and its ecological adaptability, we examined leaf morphological and anatomical structure of plants at different altitudes from 3600 to 4200 m in Leng-long Ling (Ridge), northeast of the Qinghai-Tibet Plateau. The experiment was carried out in situ and with transplantation from different altitudes to same altitude. The traits were examined using conventional ecological method, paraffin section and microscopic observation technique. The results showed that, with the increases of altitude, temperature showed a significant decreasing trend (about 0.66 ℃·100 m^-1), but there was no variation of radiation and precipitation. Leaf morphological and anatomical structure of P. nivea growing in situ at different altitudes had significant differences (P<0.05). With the increase of altitude, plant height, leaf size and specific leaf area showed a decreasing trend, while leaf dry matter content, specific leaf mass, leaf thickness, palisade and spongy tissue thickness, palisade coefficient, and leaf cell tense ratio increased. However, there were no significant differences in leaf width, specific leaf area, specific leaf mass, leaf dry matter content, cuticle thickness, epidermis thickness, spongy tissue thickness, and leaf cell tense ratio for P. nivea transplanted from 3800, 4000, and 4200 m to 3600 m. Our results suggested that whether P. nivea grew in situ or was transplanted from different altitudes to the lower altitude, leaf morphology and anatomical structure were sensitive to altitude change. Plants adapted to the environment by changing traits, and there were synergistic changes among leaf traits.

Key words: altitude gradient, transplant, morphological index, anatomical structure.