Work

Coordination of photosynthetic performance and leaf N:P stoichiometry under fluctuating coastal environmental conditions in Bolboschoenoplectus mariqueter

Year: 2026

Type: article

Abstract: Introduction The population of Bolboschoenoplectus mariqueter has substantially declined because of habitat modification and competition. Therefore, this study aimed to characterize the photosynthetic and stoichiometric traits of B. mariqueter and their environmental regulation in a natural tidal-flat population to facilitate successful conservation. Methods Light- and CO 2 -response characteristics, diurnal and seasonal dynamics of leaf gas exchange, daily carbon assimilation and transpiration, chlorophyll characteristics, and leaf nitrogen (N) and phosphorus (P) stoichiometry in a natural were investigated in a × B. mariqueter population in Hangzhou Bay, China. Random forest, variation partitioning, and redundancy analyses were used to evaluate the relationships among photosynthetic performance, leaf nutrient stoichiometry, and microenvironmental factors. Results The net photosynthetic rate (Pn), transpiration rate (Tr), and water-use efficiency (WUE) varied substantially among months. Pn and Tr showed generally coordinated diurnal dynamics, whereas daily carbon assimilation and transpiration followed partially divergent seasonal trajectories after July. Leaf N and P concentrations and N:P ratios exhibited pronounced and asynchronous seasonal variations. The random forest model explained 65%, 69%, and 42% of the variations in Pn, Tr, and WUE, respectively. Leaf P and N:P were the main predictors of Pn; N, P, and N:P, of Tr; and N and P, of WUE. Variation partitioning showed substantial shared explanatory variation among photosynthetic-pigment traits, leaf nutrient stoichiometry, and microenvironmental factors, whereas redundancy analysis (RDA) identified leaf N, P, N:P, leaf temperature (LT), vapor pressure deficit (VPD), and chlorophyll a/b (Chl a/b) as key explanatory variables. Conclusion These results indicate that photosynthetic performance and leaf nutrient stoichiometry in B. mariqueter are linked within an integrated environmental–physiological framework rather than through a simple direct relationship between leaf nutrient concentrations and carbon assimilation. Thus, P availability may play an important role in seasonal nutrient regulation. This multidimensional coordination of carbon acquisition, water use, and nutrient status may contribute to the adaptation of B. mariqueter to the dynamic coastal tidal-flat environment and provide a physiological basis for its conservation and restoration.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2026.1911028