There may not be any species more central to the New Hampshire advantage – our history, our image and our surroundings, especially at this time of year – than the sugar maple tree. Which explains why Barrett Rock is so bothered by the results of his own research and research from a graduate student.

“I think there’s a general sense within the forest community that we’re seeing the beginning of the loss   of sugar maples,” said Rock, a professor of forestry and botany at the University of New Hampshire, who has studied New England’s woodlands for decades.

He attributes the maple trees’ problems largely to the effects of climate change that is worsened by human activity and says it is was predicted years ago but is occurring faster than expected.

That loss is most obviously seen, Rock says, by a dimming in the brilliance of the sugar maple’s fall foliage over the past three years. The key point is that he means “seen” in a scientific sense, based on three years of data about such things as foliage color measured by spectral analysis of satellite photos.

“This isn’t my saying so, because I think they look good, this is the numbers saying so,” he said.

Some of those numbers are prompted by work of Martha Carlson, a Ph.D. candidate under Rock who, with her husband, owns a Center Sandwich farm that has a 60-acre “sugarbush” operation.