Phenology

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Phenology Budburst, Green-up and Green-down
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What is 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.

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What is a season?What observations can be made
to observe seasonal patterns?
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Plant growing season generally the period
between green-up and green-down.

• What happens to the cycling of water and
  biogeochemicals during the growing season?

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Budburst, Green-up and Green-down

• Why is it important to take these measurements?

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Scientists use these data to study

• Carbon and water cycles
• Regional and global vegetation patterns
• Year-to-year trends
• Plant responses to climate change
• There are many applications - e.g.,
• Agriculture
• Wild fire danger
• Animal migrations

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Ties with Satellite Missions

• GLOBE ground-based observations will help
  scientists validate estimates of growing seasons.
  
• Estimates of greenness values from remote sensing
  data vary because of problems from atmospheric
  properties, sun angle, aging of satellite
  detectors.

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Budburst Ideal Site Criteria

• Native deciduous trees
• Choose dominant overstory species Always think
  What does the satellite see from above?
• If over-story plants are evergreen conifers, use
  under-story broadleaf trees or shrubs
• Can choose multiple species to do comparative
  studies
• Easily accessible

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Budburst observations

• Twice weekly, starting at least two weeks before
  initial budburst observe selected tree(s) until
  budburst can be seen on three locations on a tree

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Green-Up and Green-Down Ideal Site Selection
Criteria

• Native deciduous trees, shrubs or grasses
• Choose dominant overstory species Always think
  What does the satellite see from above?
• If over-story plants are evergreen conifers, use
  under-story broadleaf trees or shrubs

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Green-Up and Green-Down Ideal Site Selection
Criteria

• Avoid sites near buildings or where watering or
  fertilization is done
• Easily accessible
• Try to use the same plants for green-up and
  green-down

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Green-Up and Green-Down Ideal Site Selection
Criteria

• Choose a location close to the Atmosphere and
  Soil Moisture Study Sites
• Keep the horizontal distance than 2 kilometers
• Keep the elevation difference less than 100
  meters
• Why do you think this is preferred?

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When to take Green-up observations

• Twice weekly, starting at least two weeks before
  initial budburst until leaf length stops
  increasing.

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Green-up and Green-down Trees/Shrubs Branch and
Leaf Selection

• Choose branch
• facing equator
• Exposed to sunlight (not shaded)
• Determine Genus, species
• Mark branch for identification
• Locate bud at end of branch and 3 closest
• Photos N, S, E, W

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Green-up Trees/Shrubs

• Examine bud
• Determine category Dormant, Swelling, Budburst,
  Lost
• Measure leaf length (mm) not including petiole
• Continue until leaf stops increasing in length

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Green-up Grasses

• Identify and mark 1 m2 area to study
• Exposed to sunlight (not shaded)
• Determine Genus
• Look for new shoots, mark for identification
• Measure shoot length (mm)
• Until shoot stops increasing in length

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Green-up Grasses

• Marking of buds and shoots
• Trees/bushes
• Grasses

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When to take Green-down observations

• Twice weekly, starting two weeks before initial
  green-down until leaf color change is complete or
  leaves fall off

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Green-down Trees/Shrubs

• Examine twice/week
• Use color guide to choose dominant color (if
  multiple colors) until color change stops
• Other possible observations -
• Snow covered
• Fallen (lost)

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Green-down Trees/Shrubs

• Locate and Mark 4 longest shoots within mark 1 m2
  area
• Examine twice/week
• Use color guide to choose dominant color (if
  multiple colors) until color change stops
• Other possible observations -
• Snow covered
• Fallen (lost)