Divergent photosynthesis and leaf respiration responses of four common subtropical tree species to modest warming

Abstract

Subtropical forests are vital to global carbon pools, and their responses to increasing warming may significantly influence carbon sequestration. However, how subtropical tree species adjust the photosynthesis and respiration process in response to climatic warming through phenotypic plasticity is still unclear which is critical for predicting future forest carbon dynamics. In this study we investigate the effects of controlled warming experiment (1.5 {+/-} 0.5) on growth and leaf economic traits especially photosynthesis and respiration in four common subtropical tree species. Our findings reveal that modest warming enhanced photosynthesis, stomatal conductance, and night respiration, leaf anatomical traits as well as growth in Schima superba, Ormosia pinnata, and Pinus massoniana, of those species under warming. In contrast, Castanopsis hystrix demonstrated reduced performance in all measured traits because it may lack adaptive traits critical for warming resilience, indicating a divergent response to the same environmental condition. Our findings highlight the species-specific variation in how subtropical trees adjust traits associated with trees capacity to acclimate to increased temperatures. Specifically, Ormosia pinnata, Pinus massoniana, and Schima superba may exhibit beneficial responses to warming, whereas Castanopsis hystrix may experience negative effects in future climatic conditions which alters future carbon storage and tree diversity. Thus, our study offers new insights for further research on common trees under warming to improve predictions of forest dynamics under climate change, aiding conservation efforts to address environmental pressures.