Intraspecific variation explaining species resource-use strategies in Amazonian open vegetation

Abstract

Abstract At an intraspecific scale, plants exhibit trait adjustments to their respective habitat, playing a pivotal role in species distribution across environmental gradients. We aimed to understand whether and how Curatella americana L. (Dilleniaceae) varies in leaf and wood morphoanatomical traits among three Amazon open vegetation types under distinct edaphic conditions. We tested the hypothesis that soil properties drive variation in species' functional traits and resource-use strategies. We collected plant and soil samples at seven sites (three savannas, two campinarana and two restinga) and functional traits were measured for 70 C. americana individuals. The variation in intraspecific traits was associated with soil properties. In the restinga, individuals exhibited the highest specific leaf area influenced by fine sand and sodium. However, in the savanna, soil variables prompted morphoanatomical responses related to leaf dry-matter content, leaf thickness, largest lumen resistivity, the lowest wood density and average vessel area. The campinarana sites have strong affinities for clay and pH. We highlight the continuum of conservative-acquisitive functional strategies, exhibited by C. americana across Amazonian open vegetation, showing the adaptability to diverse environmental conditions. Strategies vary within individuals based on tissue type, suggesting decoupling between leaf and wood levels, with traits operating independently at both levels.

Keywords

• Curatella americana
• ecological strategies
• intraspecific variation
• morphoanatomical traits
• soil-plant relationship