In order to explore the adaptation strategies of urban garden plants leaf traits and the relationship of different life forms to climate zone. In this study, we used Mudanjiang of Heilongjiang Province and Bozhou of Anhui Province as the research sites, 17 and 9 woody garden plants were selected respectively, measured 7 leaf morphological characters and 4 photosynthetic pigment contents. One way ANOVA was used to reveal the variation characteristics of leaf functional traits of trees, shrubs and vines in two urbans. Two-way ANOVA was used to reveal the plant leaf traits under climate and life form. Pearson correlation analysis and principal component analysis was used to calculate the correlation coefficient between leaf functional traits of plants in the two places. Leaf dry matter content (LDMC) and Vein density (VD) of different life forms in Mudanjiang were higher than Bozhou (P < 0.05), the Relative water content (RWC) in Bozhou was higher, while Vein density (VD) of trees and shrubs in two urbans were significant ((P < 0.05), but the vine was not significant. The tree and shrub species photosynthetic pigments were larger in Mudanjiang, but it was opposite in vines. Both leaf vein density (VD) and stomatal density (SD) showed a very significant positive correlation in two nrbans (P < 0.01), and both were significantly positively correlated with specific leaf area (SLA) (P < 0.05), negatively correlated with leaf thickness (LT), and the relationship between pigment content were closer. The response was obvious differences in leaf traits of different life forms species in urban to climate, but the correlations between the traits showed convergence, which reflects that the adaptation strategies of garden plant leaves to different habitats are both coordinated and relatively independent.

Background Previous studies of the relationships between traits have focused on the natural growth conditions of wild plants. Urban garden plants exhibit some differences in plant traits due to environmental interference. It is unknown whether the relationships between the leaf traits of urban garden plants differ under distinct climates. In this study, we revealed the variation characteristics of the leaf functional traits of trees, shrubs, and vines in two urban locations. Two-way ANOVA was used to reveal the response of plant leaf traits to climate and life forms. Pearson correlation analysis and principal component analysis were used to calculate the correlation coefficient between the leaf functional traits of plants at the two locations. Results Leaf dry matter content (LDMC) and vein density (VD) of different life forms in Mudanjiang were higher than those in Bozhou (P < 0.05), and the relative water content (RWC) in Bozhou was higher, whereas vein density (VD) of trees and shrubs in the two urban locations was significant (P < 0.05), but the vines were not significant. The photosynthetic pigments of tree and shrub species were larger in Mudanjiang, but the opposite was true for the vines. Both leaf vein density (VD) and stomatal density (SD) showed a very significant positive correlation in the two urban locations (P < 0.01), and both were significantly positively correlated with specific leaf area (SLA) (P < 0.05); and negatively correlated with leaf thickness (LT), and the relationship between pigment content were closer. Conclusion The response to climate showed obvious differences in leaf traits of different life forms species in urban area, but the correlations between the traits showed convergence, which reflects that the adaptation strategies of garden plant leaves to different habitats are both coordinated and relatively independent.