What is Phenology?

Plants and animals go through many changes in appearance and behavior throughout the course of a year. Studying the patterns of these changes over many years is called phenology. For plants these observations may include the first leaf, the last flower, the amount of ripe fruit, leaf color change, and even pollen production. Migration, hibernation, egg production, mating, and molting are changes that can be observed in animals. These cyclical events are called phenophases.

Gathering phenological data benefits all of us in our daily lives, even though you may have never heard of phenology before! Agriculture uses it for crop timing; health organizations predict pollen seasons; meteorologists monitor drought conditions and assess wildfire risk; and environmental scientists can project future climate changes. Phenophases are linked to the smallest environmental shifts in precipitation, temperature, and available sunlight. That is why phenological data plays such an important role in science today.

What is the Phenology Project?

USA National Phenology Network

The USA National Phenology Network brings together citizen scientists, government agencies, non-profit groups, educators and students of all ages to monitor the impacts of climate change on plants and animals in the United States. The network harnesses the power of people and the Internet to collect and share information, providing researchers with far more data than they could collect alone.

The Houston Arboretum & Nature Center is now a part of this network. We have selected 32 species of plants and 31 species of animals on which to observe and record phenological data.

Hanc Trail Map 2015Get Involved!

Houston Arboretum & Nature Center is host to many species of native plants and wildlife, making it the perfect place to observe, record data, and be a citizen scientist!

We have 3 separate phenology trails, ranging in terrain and distance, for you to pick from. Do one or do them all! Print your data sheets off at home, or stop by the Discovery Room to pick one up. Then, grab your binoculars, a pencil, and a clipboard and head out on the trails! Drop off your completed datasheets in the Discovery Room when you’re finished, or in the Bird Log box near the back door if it’s before or after hours.

Whether you want to get outdoors with the family, or yearn to find some quiet time in the peaceful forest, this is an engaging new way to experience our trails, while helping scientists around the world!

Naturalist Led Phenology Tours
Have more questions? Want some help getting started? Not sure the difference between a forb and a grass? A tree and a shrub? A bud and a blossom? That’s okay! We still need you and are here to help!
On the 2nd and 4th Saturday of each month, meet with a Naturalist at 9am in front of the Visitor Center and embark on a guided walk through one of our phenology trails.
After just a few visits you’ll be amazed at the constant changes in our plant community that often go undetected by the untrained eye!

Phenology Forms

Phenology Information Booklet

Animal Data Sheet

Courtyard Zone Data Sheet

Lawn Zone Data Sheet

Riparian Zone Data Sheet

More information on Phenology can be found here:

Helpful Links:


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