What is Phenology?
Phenology is the calendar of a tree's life — when it flowers, sets fruit, drops leaves, and flushes new growth. In Costa Rica, these events are tightly linked to the wet/dry seasonal cycle rather than temperature changes.
Key Phenological Events
- Leaf flush: Production of new leaves, often at the start of the wet season.
- Flowering: Can occur in dry season (many ornamentals) or wet season.
- Fruiting: Follows flowering; fruit maturation time varies from weeks to months.
- Leaf fall: Deciduous species shed leaves in the dry season to conserve water.
- Dormancy: Reduced metabolic activity during dry season.
Tropical Phenology in Costa Rica
Dry Forest (Guanacaste)
- January–April: Deciduous trees lose leaves; many species flower on bare branches.
- May–June: First rains trigger synchronized leaf flush and seed germination.
- Corteza Amarilla blooms spectacularly in March–April on leafless branches.
Wet Forest (Caribbean Lowlands)
- Less pronounced seasonality; flowering and fruiting more staggered.
- Some species fruit year-round.
Cloud Forest (Monteverde)
- Mist and epiphyte loads obscure seasonal patterns.
- Many species flower during the brief dry period (January–March).
Why It Matters
- Pollinator management: Knowing bloom times ensures pollination success in agroforestry.
- Seed collection: Phenological tracking identifies optimal harvest windows.
- Wildlife: Fruiting phenology determines food availability for birds and mammals.
- Climate change: Shifting phenology is an early indicator of climate impacts.