The ecological adaptability of four typical plants during the early successional stage of a tropical rainforest

Abstract

The ecological adaptability of four typical plants (two grasses: Thysanolaena maxima and Miscanthus floridulus; two shrubs: Melastoma candidum and Melastoma sanguineum) in the early successional stage of a tropical rainforest in Hainan Island of China was studied. Our purpose was to test the difference of the adaptive modes and ecological functions for four different functional groups. We measured the physiological parameters and morphological indexes to define the adaptability of the plants at this stage. Results showed that T. maxima possessed stronger water use ability, whose adaptation was mainly by the morphological architecture regulation strategy (by higher leaf self-shading). M. floridulus had greater water regulation ability and its adaptation was mainly through the physiological regulation strategy (by higher net photosynthetic rate (A) and water use efficiency). However, M. candidum and M. sanguineum integrated the morphological architecture and physiological strategies (by high A and leaf self-shading). According to the ecophysiological characteristics and adaptation modes, the plants in the early successional stage of the tropical rainforest in Hainan Island can be categorized into three functional groups: (1) physiological adaptation group, (2) morphological adaptation group, and (3) physiological and morphological integrated adaptation group.