XVI International Botanical Congess

In the montane cloud forest of Veracruz, most canopy trees are deciduous, whereas small trees and shrubs in the understory are evergreen. I contrasted foliar and reproductive phenologies in canopy and understory, and identified effects of light and microclimate on understory vegetation phenology. Canopy openness is higher in January-February. In the canopy, leaf fall peaks from November to February, and leafing and flowering peak between February-May. In the understory, higher PAR (photosynthetically active radiation) was recorded in January-March, and leafing and flowering peaks (December-March) occur earlier than in the canopy. Leafing and flowering in the understory are correlated with PAR but not with canopy openness, they are correlated with air and soil temperatures, and with soil water content but not with relative air humidity.