Forest Watch conducts basic and applied research on New England forest ecosystems. Research data is collected by teachers & students (gr. K-12), sampled from trees in their study plot.

Study Species
  • White Pine
  • Sugar Maple

The Forest Watch program is funded by the New Hampshire Space Grant Consortium, located at Univ. of New Hampshire Institute for the Study of Earth, Oceans, and Space.

Who we are... Forest Watch staff...
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White Pine Research
  The Science

The Forest Watch program studies the effects of ground-level ozone on the health of New England’s forests. K-12 students, teachers and researchers at the University of New Hampshire have been working together each year since 1991 collecting large amounts of data from white pine (Pinus strobus) trees all across New England.

  white pine data
  Forest Watch chart of ground-level ozone concentrations shows that when needles were unhealthy in the 1990s, ozone levels were high. When ozone levels began to drop, white pine health soared.
Research in the 1980s demonstrated that the white pine is a bio-indicator tree: The pine is sensitive to air pollution and ground-level ozone exposure. Many other species of trees in the New England forest are able to close their stomates against ozone when levels climb. White pine, research finds, may close stomates at very high levels of ozone but maintain open stomates at levels of 60 to 80 ppbv.

Forest Watch has confirmed the connection between ozone levels and white pine health. Over the past two decades, in all but a few drought years, white pine health has declined when ozone levels were high. White pine health has improved when ozone levels dropped. 

  pine needle cross section
  A cross section of a single white pine needle shows the vascular bundle of xylem and phloem in the center. Green mesophyll cells filled with chlorophyll surround it.
When white pines are damaged, their needles show distinct and measureable tip necrosis and chlorotic mottle. Ozone damages cells internally, reducing chlorophyll. With reduced photosynthesis, needles hold less water, make less sugar and show reduced growth of needles and reduced retention of needles.

These biometric measures of plant health correlate with spectral measures of light reflected from needle surfaces.  Students, teachers and UNH scientists have collaborated to build a 20-year data base of white pine measures, tracking the impact of low level ozone on the New England forest. Forest Watch Data Books provide a remarkable history of our measurements and findings.

More information:
White Pine Materials for Schools...