Popis: |
In addition to salinity, mangroves must also endure prolong exposure to high irradiance and leaf temperature even when stomatal conductances and photosynthetic rates are extremely low (1). For these reasons, mangroves are often targeted for studies of photoinhibition (2). Bjorkman et al. (1) in describing mangrove photosynthesis have suggested that excessively high irradiances do not damage mangrove leaves because of their ability to dissipate excess excitation in the form of radiationless energy (3), albeit at the cost of lower photochemical efficiency. In this study, we have examined the photosynthetic characteristics of the mangrove, Bruguiera paruiflora, under natural conditions in Queensland, Australia. The results suggest that rapid adaptation to extreme conditions can be accomplished without the loss of photosynthetic efficiency and that regulation of photosynthesis by rapid changes in carboxylation capacity may be important. |