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Abstract Ensuring the sustainability of forest ecosystems requires understanding the mechanisms underlying tree growth and predicting their relative influence across taxa and environments.Functional ecology posits that variation in tree growth is related to individual differences in functional traits, which serve as proxies for resource acquisition and investment strategies. However, studies of trait–growth relationships have produced inconsistent results, likely due to unaccounted factors like interspecific interactions, ontogeny, differing leaf habit strategies, and variation in resource acquisition and allocation.We investigated the utility of key functional traits as predictors of tree height growth rates in common garden experiments in the absence of interspecific interactions. We posit that trait–growth relationships vary with age and between two groups relating to leaf habit: deciduous and evergreen species.Using data from 38 tree species planted in monoculture plots across seven sites of the International Diversity Experiment Network with Trees (IDENT) in North America and Europe, we compiled height growth rates over 9 years post‐germination. We modelled growth using a Bayesian hierarchical generalized linear model incorporating four above‐ground functional traits related to resource acquisition and investment: specific leaf area (SLA), wood density (WD), leaf dry matter content (LDMC) and seed mass (SM). Improvements in predictive power due to the variation of trait effects with age and leaf habit were evaluated via alternative hypothesis‐driven models, using the Expected Log Pointwise Predictive Density (ELPD) as a performance measure.Trait effects on growth varied with age and leaf habit, shifting between positive and negative effects, reflecting changes in resource acquisition and investment strategies. The relationships between traits and growth were strongest during the first three growing seasons for deciduous species and during the seventh to the ninth for evergreen species. Accounting for age and leaf habit substantially improved predictive power.Synthesis.Traits are not consistently associated with tree growth rates but instead reflect dynamic resource acquisition and investment strategies over time and between deciduous and evergreen species. Despite this variability, our findings confirm the utility of functional traits to predict tree growth rates, especially when trait effects are considered to vary with age and leaf habit.
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This content will become publicly available on December 1, 2026
Trait coordination reveals the fast–slow plant economics spectrum along the vertical canopy profile in central Amazonian forests
Abstract Understanding how environmental drivers affect tree functioning is essential to improve predictions of tropical forests' response to climate change. While functional traits directly influence tree performance, our understanding of how canopy environments shape their coordination and variation along the vertical forest profile remains limited.We quantified annual growth rates in terms of above‐ground biomass (AGB), the maximum efficiency of photosystem II (Fv/Fm) and six tree functional traits related to water transport (xylem density and Huber value), leaf morphology (leaf size, angle and stomatal density) and photosynthesis (specific leaf area) along the vertical forest profile in an old‐growth central Amazonian forest.To investigate the influence of canopy environments and ontogenetic stages on the variation of these traits, we divided the forest into three vertical strata defined by height from the ground (S1: 0–20 m; S2: 20–40 m; S3: >40 m). We sampled 162 branches and 486 leaves from 54 trees of 10 species, encompassing at least five of the most abundant species per stratum. Path analysis and correlation matrices were used to explore the links between canopy environments, traits and the ‘fast–slow’ plant economics spectrum.We found significant effects of height on relative tree growth, leaf size and specific leaf area. Trait correlations varied across strata suggesting an ecological stratification of canopy functional niches. Trait–growth correlations increased in number and strength with increasing height, suggesting greater trait‐mediated growth control in large trees.Our results reveal how traits and strategies on the ‘fast–slow’ plant economics spectrum are vertically distributed and coordinated along the forest profile. Our findings highlight important interactions between species and canopy environments in determining plant traits, with emergent species showing adaptive strategies at different stages of their development. Read the freePlain Language Summaryfor this article on the Journal blog.
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- PAR ID:
- 10683040
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Functional Ecology
- Volume:
- 39
- Issue:
- 12
- ISSN:
- 0269-8463
- Page Range / eLocation ID:
- 3596 to 3610
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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