Intraspecific variation in leaf traits and evolutionary plant strategies of three macrophytes across an environmental gradient in Eastern Amazon

This study explores the intraspecific trait variation and ecological strategies of three macrophyte species in the Amazon region, focusing on leaf traits and CSR strategies (competitors, stress tolerators, and ruderals). Individuals of Eleocharis interstincta, Fuirena umbellata, and Nymphaea rudgeana were examined across 22 sampling sites. Traits including leaf area, specific leaf area, and leaf dry matter content were measured, along with environmental variables. Results demonstrated significant differences in leaf traits among the species, highlighting their distinct strategies. Individuals of F. umbellata exhibited the lowest leaf dry matter content values, indicating a conservative and stress-tolerator strategy. N. rudgeana had the highest leaf area values, reflecting an acquisitive strategy and varied from a S to S/CS strategy, while E. interstincta showed intermediate trait values and a stress-tolerator strategy. Furthermore, intraspecific variation was observed within each species, influenced by environmental factors (nutrient availability, water conductivity, dissolved oxygen, and sediment composition). Our findings contribute to understanding the intraspecific trait variations and ecological strategies of macrophytes in the Amazon region, providing insights into plant adaptation and response to environmental changes. Future research should incorporate additional traits and encompass different macrophyte life forms, further enhancing our understanding of their strategies and responses to ongoing environmental change.