hide
Free keywords:
-
Abstract:
Phenotypic traits and their associated trade-offs have been shown to have globally consistent effects on individual plant physiological
functions1–3, but how these effects scale up to influence competition,
a key driver of community assembly in terrestrial vegetation, has
remained unclear 4. Here we use growth data from more than
3 million trees in over 140,000 plots across the world to show how
three key functional traits—wood density, specific leaf area and
maximum height—consistently influence competitive interactions.
Fast maximum growth of a species was correlated negatively with
its wood density in all biomes, and positively with its specific leaf
area in most biomes. Low wood density was also correlated with
a low ability to tolerate competition and a low competitive effect
on neighbours, while high specific leaf area was correlated with
a low competitive effect. Thus, traits generate trade-offs between
performance with competition versus performance without
competition, a fundamental ingredient in the classical hypothesis
that the coexistence of plant species is enabled via differentiation
in their successional strategies5. Competition within species was
stronger than between species, but an increase in trait dissimilarity
between species had little influence in weakening competition. No
benefit of dissimilarity was detected for specific leaf area or wood
density, and only a weak benefit for maximum height. Our traitbased
approach to modelling competition makes generalization
possible across the forest ecosystems of the world and their highly diverse species composition.
