Variation in the delta C-13 of two mangrove plants is correlated with stomatal response to salinity
- 生命科学－已发表论文 
To better understand the relationship between salinity and the carbon stable isotope composition (expressed as delta C-13) of mangrove plants and to test whether the patterns of variation in delta C-13 of mangrove plants differ from those of nonhalophytes as response to salinity, the effect of salinity on leaf delta C-13 in two dominant mangrove species, Aegiceras corniculatum and Kandelia candel, was studied. Furthermore, to determine whether the variation in delta C-13 of mangrove species is adjusted by stomatal conductance, K. candel was selected as an example, and leaf gas-exchange characteristics of the seedlings were measured. It was observed that both mangrove species had a lower leaf delta C-13 under their optimum salinity (1.50% for Ae. corniculatum and 2.00% for K. candel). This variation in delta C-13 of mangrove plants was attributable largely to stomatal adjustment as for nonhalophytes in which a strong correlation between delta C-13 and relevant photosynthetic properties is observed. This result suggests that the different response pattern in delta C-13 was a consequence of the variation in stomata in relation to the different tolerance to salinity. The optimum salinity inferred by leaf delta C-13 provides a feasible method for comparing salt tolerance between mangrove plants belonging to different species, which is useful for mangrove restoration.