Abstract:Plant respiration plays a vital role in the carbon cycle of ecosystems. Approximately, half of the carbon assimilated via photosynthesis in terrestrial vegetation anually is released through respiration,with leaf respiration contributing significantly. Leaf respiration occurs not only at night (Dark respiration, Rd), but also during the day (Light respiration, RL). Studies reveal that under light condition, leaf respiration is lower compared to dark environments, indicating that light inhibition of approximately 30%-40%. Regrettably, recent research often neglects this light inhibition, leading to an overestimation of ecosystem respiration and gross primary productivity (GPP). Thus, a comprehensive exploration of leaf day respiration becomes imperative. In this study, we conducted a study focusing on six prevalent Ficus species native to southern China's subtropical region (Ficus benjamina L., Ficus altissima B., Ficus microcarpa cv Golden Leaves, Ficus religiosa L., Ficus microcarpa L., Ficus concinna L.). We measured light respiration rate(RL,Kok method) and dark respiration rate (Rd), along with leaf traits such as leaf dry mass per unit area (LMA), leaf nitrogen content (N), leaf phosphorus content(P), Rubisco enzyme oxygenation (Vo80) and carboxylation rate (Vc80) at 80 μmol photons m-2 s-1 PPFD, and Rubisco enzyme oxygenation (Vo1800) and carboxylation rate (Vc1800) at 1800 μmol photons m-2 s-1 PPFD. Employing Pearson correlation analysis,we examined the relationship between RL and other leaf traits, subsequently utilizing stepwise regression analysis to establish an RL correlation prediction model. The results indicated that RL for the six Ficus species was lower than Rd, exhibiting an average inhibition of 38.4% and ranging from 24.1%-61.2%, and there was inter-specific variation in RL and light inhibition of respiration rate. RL exhibited significant positive correlations with Rd, A, N, Vo80, Vc80, Vo1800 and Vc1800, and exhibited significant negative correlation with LMA and not statistical correlation with P. The Stepwise regression analysis showed a model incorporating Rd, N and Vc80, which explained 96.5% of RL variation (RL=6.686+0.555Rd+0.375N+0.072Vc80). Similarly, Vc80 and N explained 74.5% of RL variation (RL/Rd =0.13+0.06Vc80+0.019N). RL and RL/Rd are affected by leaf N and Rubisco enzyme carboxylation rate (Vc), which may be caused by the intricate interplay between photosynthesis and respiration. This study culminated in the establishment of a prediction model for leaf respiration in subtropical Ficus species, providing a deeper understanding of the mechanisms behind light inhibition of respiration. The insights gained will contribute to a more accurate assessment of the leaf carbon cycle and GPP.