GLOBE Plant

Phenology

Phenology

• Phenology is the study of living organisms’ response to seasonal and climatic changes in their environment.

• Seasonal changes include variations in day length or duration of sunlight, precipitation, and temperature.

• Plant growing season generally corresponds to the period between green-up and green-down.

• Growing season directly related to global carbon fixation and the amount of CO2 in the atmosphere.

• Timing of green-up and green-down is important for understanding the global water cycle. As plants photosynthesize, they also transpire water from the soil into the atmosphere

Plant Phenology

• Green-up and green-down data are used to examine:– regional and global vegetation patterns– year-to-year trends– vegetation responses to climate change– wild fire danger– animal migrations

Phenology

• Uses of Phenology Measurements– Estimates of greenness values from

remote sensing data vary because of problems from atmospheric properties, sun angle, aging of satellite detectors.

– GLOBE ground-based observations will help scientists validate estimates of growing seasons.

Phenology

Myneni,R.B. et.al. 1997. Nature, 386, 698-702.

Increase in plant growing season lengthaccording to remotely sensed data

There’s a need for ground observations/data.

• Budburst

• Green-up

• Green-down

Plant PhenologyProtocols

• Observe trees, twice weekly, starting at least two weeks before initial budburst.

• Report date of budburst when you see leaves breaking out of the buds in three different branches of each tree.

Phenology:Budburst

• Observe buds and report dates of green-up stages and leaf growth, twice weekly, starting at least two weeks before initial budburst .

• Measure leaf blade length until length stops increasing.

• Observe leaves twice weekly, starting two weeks before initial green-down

• Report dates of green-down color changes until leaf color change is complete or leaves fall off.

Phenology:Green-up

andGreen-down

Plant Phenology: Green-down

• A First Look at Phenology • Sneak Preview of Budburst• A Beginning Look at Photosynthesis• Investigating Leaf Pigments• 2 inquiry Learning Activities on our website

www.uaf.edu/olcg

Plant PhenologyLearning Activities

• 77 schools in 11 countries

• 18 states in the US

• AK (34) and NY (6 schools)

Plant Phenology

Data Reporting

– Select deciduous native trees, shrubs or grasses.– Choose dominant over-story species – Avoid sites near buildings or where watering or

fertilization is done– If possible, choose a location close to the

Atmosphere and Soil Moisture Study Sites– Keep the elevation difference less than 100

meters

Phenology Green-up &Green-down

Site Selection

• Supports understanding of big concepts in science such as systems and cycles

• Protocols and L.A. are aligned with science and math education standards

• Easy to fit in school day schedule because of short time required for measurements/observations

• Inexpensive equipment, i.e. ruler, color chart ; majority of students are already equipped with remote sensing equipment of eyes and touch

• Offers many opportunities for student science investigations and cross-curricular integration

Why do Plant Phenology in

schools?

Research Question:

Can we observe differences in plant phenology (for same species) along an urban to rural gradient?

Phenology Field

Campaign

• Green-Up and Green-Down Site Selection– Select deciduous trees, shrubs or grasses.– Choose dominant over-story species - Green-

up and green-down data from satellites are affected predominantly by these dominant species

– If over-story plants are evergreen conifers, use under-story broadleaf trees or shrubs

– Try to use the same plants for green-up and green-down

Phenology

• Green-Up and Green-Down Site Selection– If possible, choose a location close to the

Atmosphere and Soil Moisture Study Sites– Local topography can cause weather to vary

even within short distances– Keep the horizontal distance between

Phenology and Atmosphere and Soil Moisture Study Sites less than 2 kilometers

– Keep the elevation difference less than 100 meters

Phenology

Some Deciduous species in Alaska

Quaking aspen Paper birch Black cottonwoodPopulus tremuloides Betula papyrifera Populus trichocarpa