Phylogenetic conservatism in the relationship between functional and demographic characteristics in Amazon tree taxa

Leaf and wood functional traits of trees are related to growth,
reproduction, and survival, but the degree of phylogenetic conservatism in
these relationships is largely unknown. In this study, we describe the
variability of strategies involving leaf, wood and demographic
characteristics for tree genera distributed across the Amazon Region, and
quantify phylogenetic signal for the characteristics and their
relationships. Leaf and wood traits are aligned with demographic variables
along two main axes of variation. The first axis represents the
coordination of leaf traits describing resource uptake and use, wood
density, seed mass and survival. The second axis represents the
coordination between size and growth. Both axes show strong phylogenetic
signal, suggesting a constrained evolution influenced by ancestral values,
yet the second axis also has an additional, substantial portion of its
variation that is driven by functional correlations unrelated to
phylogeny, suggesting simultaneously higher evolutionary lability and
coordination. Synthesis. Our results suggest that life-history strategies
of tropical trees are generally phylogenetically conserved, but that tree
lineages may have some capability of responding to environmental changes
by modulating their growth and size. Overall, we provide the largest-scale
synopsis of functional characteristics of Amazonian trees, showing
substantial nuance in the evolutionary patterns of individual
characteristics and their relationships.