Scientists Say: Phenology

This field tracks life cycle patterns and links the changes to environmental cues

a closeup of a budding tree branch

Seasonal changes, such as increased daylight and warmer weather, can signal to plants when it's safe to begin budding for the spring. Phenology is the field that studies how biology links up with non-biological changes throughout the year.

Olga Pankova/Getty Images

Phenology (noun, “Fen-AW-luh-jee”)

Phenology is a field of science. It studies the seasonal and environmental cues that trigger life-cycle changes in living things.

Imagine a tree as winter turns to spring. Bright green buds appear on branches that had been bare. Leaves unfurl and flowers begin to bloom. A phenologist might ask: What causes the tree to begin budding in the spring? Do longer days trigger the change? Or perhaps warmer weather?

Phenology explores how all types of life change throughout the year. For instance, many fish reproduce, or spawn, in coastal regions. The young fish then move into the open ocean as they grow into adults. In the Gulf of Mexico, red drum tend to reproduce near shore between August and November. Red snapper spawn in the area between June and August. Neither species checks a calendar to know when it’s spawn season. They respond to changes in water temperature, ocean currents and daylight hours.

Phenologists also study how climate change is altering the environmental cues that living things respond to. Higher global temperatures can trigger plants to bud earlier in the year. Climate change can also affect the migration timing of birds and other animals. This cause-and-effect knowledge is important. It may allow us to better manage future changes to our planet’s life forms as global temperatures keep rising.

In a sentence

The field of phenology might investigate the link between seasonal pollen levels and allergy symptoms in humans.

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Katie Grace Carpenter is a science writer and curriculum developer, with degrees in biology and biogeochemistry. She also writes science fiction and creates science videos. Katie lives in the U.S. but also spends time in Sweden with her husband, who’s a chef.