Abstract
Life history variation in trees is a ubiquitous feature of tropical
forests that may facilitate the niche partitioning of light. However,
many tests have failed to detect light partitioning by saplings in gaps,
which may reflect the stochastic nature of understory light penetration
and recruitment. We argue that tree size is a critical component of
niche partitioning that is more tightly linked to light availability. To
account for size, we use a scaling framework to assess patterns of
growth, abundance, mortality, and richness across life histories from
>114,000 trees in a primary, neotropical forest. Relative
abundance, productivity, and richness shift ~1−2 orders
of magnitude with tree size: from shade tolerant, slow trees dominating
the understory to parity with rapidly growing fast and long-lived
pioneer species in the canopy. Life history tradeoffs promote vertical
niche partitioning in tropical forests.