Trait-based approaches to calculate ecological strategy is important for understanding forest succession dynamics. However, the functional traits and ecological strategy change during succession remain poorly understood. We measured key leaf traits and calculated scores for CSR ecological strategy for 13 co-existing species in different successional stages in tropical lowland rain forests. We analyzed the patterns of functional traits and CSR strategies varied along the succession. The relationship between CSR strategy and environmental factors was examined. Our research results are as follows: (1) In older plots, LDMC was generally lower and SLA was generally higher than younger plots with the succession, the functional traits of the successional co-existing tree species changed, and SLA and LDMC showed significant differences. (2) The co-existing tree species’ strategies shifted from S/CS and CS strategies to CS/CSR and CS strategies along the succession. (3) Ecological strategies are linked to different combinations of environmental factors across the four successional stages. Our study suggests that the co-existing tree species in different succession stages of tropical lowland rain forests have a high degree of resistance and a conservative ecological strategy, which is significantly related to canopy openness, soil water content, and soil nutrients.

Plant ecological strategies are shaped by long-term adaptation to the environment and are beneficial to plant survival and reproduction. Research is ongoing to better understand how plants best allocate resources for growth, survival and reproduction, as well as how ecological strategies may shift in plant communities over the course of succession. In this study, 12 forest dynamics plots in three different successional stages were selected for study in the tropical lowland rainforest ecosystem of Hainan Island. For each plot, using Grime’s competitor, a stress-tolerator, the ruderal (CSR) scheme and using the CSR ratio tool “StrateFy”, an ecological strategy spectrum was constructed using functional trait data obtained by collecting leaf samples from all woody species. The ecological strategy spectra were compared across successional stages to reveal successional dynamics. The results showed: (1) The ecological strategy spectra varied among forest communities belonging to three different successional stages. (2) The community-weighted mean CSR (CWM-CSR) strategies shifted with succession: CWM-S values decreased, while the CWM-C and CWM-R values increased. Overall, shifts in plant functional traits occurred slowly and steadily with succession showing complex and diverse trade-offs and leading to variation among the ecological strategy spectra of different successional stages.