Abstract: This research investigated the species composition of 21 woody plants in the low altitude area (700-1 500 m) dominated by evergreen broad-leaved forest and deciduous broad-leaved forest and the high altitude areas(2 100-3 400 m) dominated by coniferous and broad-leaved mixed forest and subalpine coniferous forest in the Motianling northern-facing slope and determined six plant functional traits such as the leaf area (SLA), leaf dry matter content (LDMC), leaf phosphorus content (TPC) and nitrogen content (TNC), carbon content (TCC) and leaf thickness (LT) for 104 species. This paper discussed variation and correlation of woody plant functional traits of Motianling North-facing slope using correlation analysis. The results showed that:(1)SLA, LT and TCC in high altitude area were significantly higher than those in low altitude area. On the contrary, LDMC and TNC were higher in the low altitude area. (2)SLA showed a decreasing trend with the increase of altitude gradient. In contrast to SLA, both LDMC and LT showed an increasing trend with the increase of altitude. TCC showed an increasing trend with the increase of altitude in high and low altitude area. And the change of TNC and TPC in the low altitude area with the altitude gradient was opposite to the high altitude area. TNC and TPC showed a decreasing trend with the increase of altitude gradient in high altitude area and showed an increasing trend with the increase of altitude in the low altitude area. (3) Whether the high altitude areas or low altitude areas, there was extremely significant negative correlation (P<0.01) between SLA and LDMC, LT and TCC. And there was very significant positive correlation (P<0.01) between LDMC and LT, TCC, too. The relationship between leaf function of woody plant traits and different altitudes on the northern slope of the ridge altitude ferris, which reflected the different leaf functional traits of woody plants in the region to the coordinated response and adaptation for environmental heterogeneity determined by elevation.

Key words: functional traits, variation and correlation, altitudinal gradient, Motianling