Abstract:
The study of phenological patterns in plant communities is of vital importance for understanding
the temporal cycles of ecosystems, but there is little information on the diversity of phenological patterns that
can occur at the intraspecific level, as well as the genetic or environmental factors causing this variation. In
Handroanthus ochraceus, a deciduous tree species of neotropical dry forests, ecophysiological studies have
proposed the release of water stress as the mechanism that triggers flowering and the sprouting of new leaves.
During four years, I observed the cycles of leaf fall, flowering, fruiting, and new leaf production in seven Costa
Rican sites that differed in their proximity to water courses and in soil moisture. Six were located in dry forest
areas, and one in premontane forest. There were two general phenological patterns: the explosive, where trees
depend on the first rains for floral anthesis and the expansion of leaf meristems, and the staggered pattern, with
unsynchronized flowering at the beginning and middle of the dry season, independently of rainfall. Although this
phenological variation has been previously recognized, the occurrence of these two patterns is not determined by
the proximity of water courses, contradicting phenological models proposed for this tree species.
