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Yellowing of pine needles spreads across region


July 02, 2014
NORTH COUNTRY— Some white pine trees in the region are under attack: fungal infestations are causing the yellowing of needles. The problem has become more evident in the last few weeks. The expansion of the fungi's effects is especially visible along some busy roads, such as Route 116 between Littleton and Whitefield.

Grafton County Forester Dave Falkenham provided insights into the needle problem. "The yellowing is actually caused by three separate fungi," he said. "Many state and federal forestry agencies are working to get a grip on the situation so that they can provide management information to landowners," Falkenham continued.

Last year's weather receives the blame for spread of the fungi. According to a Cooperative Extension press release, the wet spring last year caused a buildup of fungal spores. The fungi affected interior needles of the trees as new shoots were beginning to grow.

Even with the observations of science, the next steps can be difficult to suggest when dealing with forest pests. As Falkenham noted on the pine yellowing, "What to do is not exactly clear at the moment, and it may never be." The damaged needles will fall off, and new growth should quickly bring the trees back to a regular evergreen look.

Fortunately, mass pine death is not expected from this latest round of fungi. As Falkenham said, "Word has it that the healthy trees will regenerate their needles and live on."

Some weaker trees do face danger, however. As Falkenham concluded, "The question for me is how many defoliations a tree can take before eventual mortality is the better option for the tree. Re-foliating takes a lot of energy and may impact reproduction and vitality."

A 2011 U.S. Forest Service study of white pine damage from fungi focused on New Hampshire, Maine and Vermont. A notable spread of the fungi was seen throughout the sample areas from April to June. "These fungi are expected to continue to cause damage in years following unusually wet springs," the study concluded.

White pine (pinus strobus) is a common softwood tree in the eastern United States. In colonial times, some white pines grew to more than 200 feet tall, and the species has been a respected source of lumber for centuries. Ship masts were a common use of the tree. Although the largest white pines succumbed to logging decades ago, the tree is known for a rapid growth rate and commanding stature throughout its natural range.

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