Leaf trait spectrum of mangroves: across and within species

Mangroves are widely recognized as one of the most carbon-rich ecosystems. However, the impact of different species, especially slow- and fast-growing ones, on carbon stocks can vary significantly 1 . These findings have generated a strong interest in understanding the diversity of resource-investment strategies among mangrove species. The global leaf economic spectrum holds the potential for identifying these strategies in mangroves 2,3 . Nevertheless, it remains unclear whether leaf economic traits of mangrove species exhibit expected coordination patterns. Through the analysis of 36 widely distributed mangrove species, we demonstrate that the cross-species trait spectrums of mangroves encompassing both true mangroves and mangrove associates align with findings from global vegetation analysis 2 . The distinct strategies between mangrove groups indicated by trait spectrums are consistent with previous observations 4 . However, the cross-species trait spectrums are not consistently valid in identifying strategies within or between mangrove species. Through conducting a case study, we provide empirical evidence that a fast-growing species (having a greater photosynthetic capacity and tree height) could be positioned towards the slower end of trait spectrums compared with slow-growing species when living in hyper-saline soils. Contrary to the common assumption 5,6 , the greater mass per leaf area of the fast-growing species is primarily derived from thicker leaves and a higher phosphorus content per leaf area compared with the slow-growing species. These findings suggest that the cross-species trait spectrum may have limitations in accurately identifying resource-investment strategies in plants with thick leaves.