Objective  Considering the leaf functional traits of Populus davidiana in Wudalianchi Volcano of northeastern China, thus we can recognize the adaptation of plant to volcanic environment and their resource utilization strategies to slopes, so as to provide reference for plant adaptation mechanism in special habitat and micro terrain habitat.

  Method  The variations of leaf traits of P. davidiana in different slopes and ages of volcanoes were studied, such as leaf area (LS), leaf thickness (LT), specific leaf area (SLA), leaf dry matter content (LDMC), leaf carbon content (LCC), leaf nitrogen content (LNC), leaf phosphorus content (LPC), and leaf nitrogen phosphorus ratio (LNP), further the correlation and principal components of leaf functional characters were analyzed.

  Result  (1) Except for LCC, other leaf functional characters were significantly different between north and south slopes. LT, LDMC, LNC and LNP of the south slope were higher than those of the north slope, while LS, LCC and LPC of the south slope were smaller than those of the north slope. (2) There were significant differences in SLA, LCC and LPC between new and old volcanoes, but not in old volcanoes. (3) LT and LDMC were negatively correlated on the south and north slopes, LNP and LNC were positively correlated, LNP and LPC were negatively correlated on the south slopes, north slopes and volcanoes. (4) In volcanic environment, LNP, LPC, LNC and LS play an important role in the differentiation of leaf functional traits.

  Conclusion  The variation of functional traits of P. davidiana is related to the particularity of volcanic eruption in Wudalianchi Volcano, P. davidiana adapts to the north-south slope environment by adjusting its functional traits to form different survival strategies, and the growth of P. davidiana is mainly limited by nitrogen in Wudalianchi. The volcanic forest ecosystem is a special environment, studying the volcanic vegetation succession and plant functional properties needs to be further discussed in combination with the special situation of volcanic eruption.