Abstract
1.Soil water and nutrient availability are key drivers of tree species distribution and forest ecosystem functioning, with strong species differences in water and nutrient use. Despite growing evidence for intraspecific trait differences, it remains unclear under which circumstances the effects of environmental gradients trump those of ontogeny and taxonomy on important functional dimensions related to resource use, particularly in tropical forests. 2. Here we explore how physiological, chemical and morphological traits related to resource use vary between life stages in four species within the genus Micropholis that is widespread in lowland Amazonia. Specifically, we evaluate how environment, developmental stage and taxonomy contribute to single trait variation and multi-dimensional functional strategies. 3. We find that environment, developmental stage and taxonomy differentially contribute to functional dimensions. Habitats and seasons shape physiological and chemical traits related to water and nutrient use, while developmental stage and taxonomic identity impact morphological traits -especially those related to the leaf economics spectrum. 4. Our findings suggest that combining environment, ontogeny and taxonomy allows for a better understanding of important functional dimensions in tropical trees and highlight the need for integrating tree physiological and chemical traits with classically-used morphological traits to improve predictions of tropical forests response to environmental change.