Seasonal Periodicity in the Growth and Development of some Forest Trees in Nigeria I. Observations on Mature Trees

Abstract

Observations made on a number of rain forest tree species in the Botanical Garden of the University College of Ibadan, Nigeria, show that there is a marked annual periodicity in leaf production, leaf-fall and flowering. Ibadan is at the northern limit of the rain forest zone of southern Nigeria and the climate is markedly seasonal with respect to rainfall. But the seasonal changes in the vegetation do not synchronize with the corresponding changes in rainfall. The seasonal rhythm in the vegetation may be due to internal factors or to external factors other than rainfall, such as temperature and day-length. The importance of these requires further investigation.