Differences in water and carbon use strategies for photosynthesis in true mangrove and semi-mangrove plants
Intertidal habitats are extremely stressful for plants;still,they favor true mangrove species over semi-mangrove species.This study compared the carbon assimilation and water use strategies of the two types of mangrove plants using five species from each type from the Qinglan Nature Reserve in Wenchang,Hainan,China.Their photosynthesis and water potential dynamics were measured,the water use efficiency(WUE)was calculated,and trait correlations were analyzed.The results showed no significant difference in carbon assimilation rate between the two types of mangrove species.The true mangrove plants had higher stomatal conductance,transpiration rate,stomatal limitation value,and leaf predawn and midday water po-tential but lower WUE and intrinsic WUE than the semi-mangrove plants.Most correlations between the photosynthetic parameters were significant across the two types.Still,the correlations between photosyn-thetic rate,leaf predawn and midday water potential,and WUE were only significant among the true man-grove plants.This study highlights the key contribution of leaf stomata to the integrated regulation of pho-tosynthesis,water potential and water use efficiency in the true mangrove plants.The observed weakness of such regulation in semi-mangrove species may have limited their distribution in intertidal zones.
mangroveintertidal zonecarbon assimilationwater use efficiencystomatal control
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NSTL
万方数据
