Tropical Forest Foliar Phenology

Research on Barro Colorado Island and surrounding sites has led to important insight about the causes and consequences of tropical forest leaf phenology. Field sampling coupled with remote sensing have documented a wide range of phenological patterns at local and landscape scales. At the local scale, evergreen, partially dry season deciduous, and fully dry-season deciduous species coexist. A stand-level moisture manipulation revealed that soil water availability has limited effects on leaf phenology. Other factors, such as atmospheric water content and solar irradiance, are likely to be important. At the landscape scale, seasonal climate variation is important, but geology, soils, and nutrient availability also affect deciduousness. Long-term phenological records have established responses to climate anomalies, including reduced leaf production and increased reproduction during El Niño events. Concurrent collection of physiological and morphological trait data has refined understanding of the role of phenology in life history strategies, indicating that a suite of leaf, wood, and root traits allow deciduous species to avoid drought impacts.