September 1, 1997
Contact: Denise Hart, 603-862-0322
UNH RESEARCHERS PAIR UP WITH K-12 STUDENTS TO DECODE THE
WHITE PINE NEEDLE
DURHAM, N.H.-- There's a world of life waiting to be decoded from the three-sided white pine needle.
Just ask Gary Lauten, research scientist and coordinator of the Earthday: Forest Watch Program at the University of New Hampshire's Institute for the Study of Earth, Oceans, and Space (EOS). The program lets K-12 students study the health of New England forests for clues to atmospheric and climate change impacts.
Students become partners with UNH research scientists, studying white pine trees as bioindicators of low-level, or tropospheric, ozone commonly known as the "bad" ozone associated with unhealthy levels of air pollution. The "good" ozone occurs naturally in the upper atmosphere and protects the Earth from ultra-violet rays.
The National Science Foundation-funded program extends the original Forest Watch Project, which included 60 schools in New Hampshire and Maine, to 33 additional schools in Vermont, Connecticut and Massachusetts. Lauten and a group of Forest Watch teachers develop inquiry-based curriculum materials to guide students' investigations.
Trees naturally produce a certain amount of air pollution called volatile organic compounds, which can interact with the Sun's energy and other atmospheric compounds to produce low-level ozone. However, human activity contributes more to air pollution and low-level ozone in the Northeast than the naturally occurring pollutants.
Low-level ozone is created when auto exhaust fumes, volatile organic compounds-- like solvents used in manufacturing--and sunlight combine. A hot day with strong sun turns nitrous oxides present in these compounds into low-level ozone. This is of concern to scientists who observe an increase in these and other "greenhouse gases" that in turn are projected to increase climate temperatures over time.
"It becomes extremely critical in the Northeast," says Lauten. "When a Bermuda high causes stagnant pools of polluted air over the Gulf of Maine. A hot day with an on-shore air flow brings the ozone-laden air right to us. Acadia National Park is the second most polluted national park in the United States."
Pine needles react to low-level ozone in two ways: chlorotic mottle, a lightening of the green needles that produces a yellowing on one side of the needle only; and tip necrosis, a browning of the needle tips.
Students measure needle length from the last growing season, determine the wet and dry weight of the needles, conduct chlorophyll extraction, and figure the number of years needles have been retained on a branch. According to Lauten, a healthy white pine tree retains three years of growth. The data accumulated to date indicates that white pine in the seacoast New Hampshire and Maine region is retaining predominately one year of growth.
White pine is a useful bioindicator of low-level ozone as it is indigenous to about 1/4 of the United States, says Lauten. The trees range from western Michigan to North Carolina. Other types of pine, like the Jeffrey pine in the Los Angeles basin and the loblolly pine in the southern states, are also susceptible to the damaging effects of low-level ozone.
According to Lauten, the low-level ozone often travels with acidic fog, which in this part of the country is caused by sulfur compounds that are a by-product of coal-burning plants in the midwest. The acidic fog has been blamed for forest dieback on mountain sides in New England and upstate New York. Increasing levels of ozone and fog acidity are examples of changes in the chemical climate that have occurred in recent years in the northeast region of the country.
Lauten and Shannon Spencer, research technician and coordinator of the Boreal Forest Watch project (a sister project in the Canadian provinces of Saskatchewan and Manitoba), will participate in the New England Regional Climate Change Impacts Workshop hosted by EOS Sept. 3-5. Representatives from the six New England states and upstate New York, which share one general climatic region, will share observations concerning climate change impacts and engage in a dialogue with scientists researching climate change. The researchers see programs such as Forest Watch as an important part of the knowledge dissemination process concerning the issues and impacts of climate change. "Our goal is to bring the facts to the people who need them to make informed decisions," says Spencer.
"Hopefully, students will see they can have an impact on environmental policy," says Lauten. "They are helping us to create a long-term data set to monitor what is going on-specifically with white pines and in the future, with other pines as well."
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