Precipitation gradients, plant biogeography, and the incidence of drip-tips in Cerrado plant species

Examining how both climate and species distribution patterns
correlate with leaf morphology can give insights into the ecological and
evolutionary patterns that drive adaptive selection of leaf form and
function. Drip-tips are a common feature of leaves in rain forest tree
species; they are thought to be an adaptation that aids leaf drying and
maximizes photosynthesis in areas with high-rainfall climates. We tested
whether this macroecological pattern holds true across the precipitation
gradients in a non-rain forest region – the woodland savannas of Brazil
known as the Cerrado – and compared our results with previous studies from
Amazonia. Drip-tips were, as expected, less common overall in the drier
Cerrado than in Amazonia. In addition, within the Cerrado, drip-tips were
more prevalent in areas with higher rainfall as well as in Cerrado sites
that were closer to Amazonia. Moreover, species that occurred across both
the Cerrado and Amazonia had drip-tips more often than species that w...