ObjectiveBy taking typical shade-intolerant and shade-tolerant tree species in northeastern China as objects, this study discusses the changing pattern of functional traits along geographic gradient and the underlying causes, which could provide scientific support for predicting the response and adaptation strategies of typical tree species to future environmental changes.

MethodMethod of standardized major axis regression was applied to examine the intraspecific correlation among tree height, specific leaf area and wood density; and method of partial correlation analysis was applied to analyze the relationship between functional traits and climatic factors.

ResultThere was no significant intraspecific correlation among tree height, specific leaf area and wood density. The geographical distribution pattern of plant traits changed with tree species, the height of Betula platyphylla, Fraxinus mandshurica and Acer pictum decreased with the increase of longitude; the height of Populus davidiana, Fraxinus mandshurica and Acer pictum decreased with the increase of latitude; the height of Betula platyphylla and Fraxinus mandshurica increased with elevation. The specific leaf area of Betula platyphylla and Populus davidiana decreased with increasing longitude, while that of Fraxinus mandshurica and Acer pictum increased with increasing longitude; the specific leaf area of Betula platyphylla, Populus davidiana and Fraxinus mandshurica increased with latitude. The wood density of Acer pictum increased with longitude, while that of Quercus mongolica decreased with latitude. The relationship between plant traits and climatic factors showed that the tree height of Betula platyphylla was negatively correlated with annual mean temperature, and the tree height of Betula platyphylla, Populus davidiana, Quercus mongolica, Fraxinus mandshurica and Pinus koraiensis was positively correlated with annual precipitation; the specific leaf area of Betula platyphylla was negatively correlated with annual precipitation, while that of Quercus mongolica, Populus davidiana and Fraxinus mandshurica was negatively correlated with annual mean temperature; The wood density of Quercus mongolica had significant positive correlation with annual mean temperature, while the wood density of Acer pictum was negatively correlated with the annual mean temperature.

ConclusionGeographical patterns of functional traits and their underlying environmental driving mechanisms vary with tree species. In summary, tree height and specific leaf area are separately affected by precipitation and temperature; wood density is relatively stable, which is not significantly affected by climatic factors.