Phenology, << fih NOL uh jee, >> is the study of when certain biological events that depend on climate take place. Phenologists study how these events are affected by seasonal weather changes. The events include the migration of birds, the hibernation of animals, and the sprouting and flowering of plants. Farmers and others whose work is affected by weather can use the information to plan their activities. For example, in some areas alfalfa is ready to be cut about 30 days after the common lilac blooms. Farmers in these areas can predict when they will have to cut their alfalfa by observing when lilacs bloom.
Scientific organizations in the United States and other countries have formed networks of people who observe and report on certain phenological events. The organizations use the information to make phenological maps. Lines on the maps connect the places in which living things reach a certain stage at the same time.
Artificial satellites provide data on atmospheric temperatures, solar radiation, and the reflection of the earth’s surface. This information helps scientists detect certain phenological events worldwide. For example, phenologists use this information to determine when vegetation will become green–or turn brown–in various regions. The data can be used to develop mathematical models of the life cycles of plants and animals raised in different climates.
