COMPARING DISTINCT LEAF FUNCTIONALITIES OF ACER RUBRUM AND ACER SACCHARUM UNDER EXTREMELY HIGH TEMPERATURES IN SUBTROPICAL REGIONS

Acer spp.plants are popular colorful foliage species used for landscape gardening, as their unique ornamental value is an important developmental resource for introduction and cultivation.For this study, Acer saccharum and Acer rubrum were employed as research models.Acer buergerianum, which is a native Chinese species of the same genus, was used as a control to compare differences in the anatomical characteristics of leaves, physiological photosynthetic parameters, and leaf construction costs of the three species and to explore their adaptability to extreme climatic conditions.The results revealed that the thickness of the leaf tissues and photosynthetic capacities of A. rubrum and A. saccharum were lower than that of A. buergerianum.Further, the costs of leaf construction for both A. rubrum and A. saccharum were significantly lower than that of A. buergerianum.Finally, A. saccharum had lower inputs in leaf construction, which facilitated the rapid occupation of higher ecological niches in suitable environments.However, in contrast to A. saccharum, A. rubrum possessed thicker succulent leaf tissues and strong photosynthetic capacity; thus, they were more likely to survive in hot dry environments.This study is informative for guiding selective plant introduction in subtropical regions.