Data for: The interplay of environmental cues and wood density in the vegetative and reproductive phenology of seasonally dry tropical forest trees

The great phenological diversification characteristic of seasonally dry
tropical forests (SDTF) suggests that these patterns result from a complex
interplay between exogenous (e.g., climatic) and endogenous (e.g.,
morphological, physiological, anatomical) factors. Based on the
well-established relationships of wood density with water-storing capacity
and cavitation vulnerability in woody plants, we hypothesized differential
vegetative and reproductive phenological responses to environmental cues
for hardwood and softwood species. To test this hypothesis, we compared
phenological patterns of pairs of conspecific populations of 10 species
differing in wood density, occurring in two localities with slightly
different climatic regimes, and evaluated the influence of three
environmental variables (rainfall, photoperiod, temperature) on them. Our
results, based on the assessment of the overlap of the phenological curves
of conspecific populations occurring in different sites and on linear
modeling, showed different effects of the environmental factors on
phenophase attributes, depending on wood density of the study species,
thus supporting our hypothesis. Leaf out in softwood species took place in
the dry season, they shed the foliage at the first signs of drought, and
once leafless, they flowered and fruited shortly after. By contrast,
hardwood species bore leaves and flowers in the rainy season, shed their
leaves several months after the rain ceased, and produced fruits during
the dry season. We conclude that the role of environmental variables in
cueing growth and reproduction cycles in SDTF tree species is interrelated
with their wood density, a key endogenous factor crucially linked to plant
hydraulics in these water-limited ecosystems.