Periodicity (Phenology, Aspection)
It refers to the study of seasonal changes in the community, that is, the periodic phenomena of organisms in relation to their climate. Periodicity is a strongly fixed characters in plants. Different species of plants have different periods of seed germination, vegetative growth, flowering and fruiting, leaf fall, seed and fruit dispersal, and dissemination of seeds.
Such data for each species in a community is recorded. A study of the data and time of these events is termed as phenology. In other words, phenology is the calendar of events in the life history of a plant. Diagrammatic representation of such events is known as phenograms.