USA NPN National Phenology Network

Taking the Pulse of Our Planet

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Juniper Pollen Program Landing Page

Project Goals

The purpose of this effort was to model pollen release and concentrations. Improved models: 

  • support public health decisions for asthma and allergy alerts in New Mexico, Texas and Oklahoma
  • augment the Centers for Disease Control and Prevention's Environmental Public Health Tracking Network
  • extend surveillance services to local healthcare providers subscribing to the Syndrome Reporting Information System (SYRIS)

The real-time models are based on weather data and satellite information and verified by on-the-ground observations.

During this project, observers tracked the following species:

and made observations on the following phenophases:

  • Pollen cones - In at least 3 locations on the plant, an unexpanded male pollen cone (or strobili) or an expanded cone with unbroken pollen sacs is visible. Do not include spent male cones that have released all of their pollen but remain on the plant.
  • Pollen release - In at least 3 locations on the plant, pollen is released from a male cone when it is gently shaken or blown.
  • Full pollen release - For the whole plant, at least half (50%) of the male cones release pollen when gently shaken or blown.
  • Unripe seed cones - One or more unripe female cones (or “berries”) are visible on the plant.  Unripe female cones are berry-like and green in color.
  • Ripe seed cones - One or more ripe female cones (or “berries”) are visible on the plant.  The berry-like female cones are considered ripe when they have changed color.

Also, more information can be found on Dr. Estelle Levetin's Juniper Pollen Project webpage and homepage.


This effort to develop a decision support system for human health related to asthma is funded by the National Aeronautics and Space Administration (NASA) Research Opportunities in Space and Earth Sciences (ROSES) program which supports basic and applied research in support of NASA's Science Mission Directorate (SMD). 

Last updated January 2017