Forests in Peril

New York Times
Published: October 7, 2007

Forests cover nearly 60 percent of New York, New Jersey and Connecticut, and there is no question that they will continue to exist.

But a concern is growing: What will they look like?

Will the forests of the future resemble today’s, or will they be a green tangle of alien plants devoid of native oaks, maples and beeches?

That is the worst-case scenario envisioned by experts like Dr. Emile DeVito, manager of science and stewardship at the New Jersey Conservation Foundation.

The pressure of development, the exploding deer population and the proliferation of invasive plants and insects on the region’s native species is threatening the woodlands of New York, New Jersey and Connecticut, according to forest managers, scientists and public officials.

“It is a quiet crisis,” said Carl P. Schulze Jr., director of the division of plant industry in the New Jersey Department of Agriculture.

“The average person sees that the woods are green,” he said, “and doesn’t understand that foreign species — a form of biological pollution — are outcompeting” native vegetation.

For now, the big trees are still there. But Dr. DeVito said it is the changes taking place in the “understory,” the layer of vegetation beneath the forest canopy, that are causing the most concern.

From state to state and forest to forest, the situation is variable and dynamic. “There is a lot of healthy forest left,” said Dr. Joan Gardner Ehrenfeld, an expert on invasive species who is a professor in the Department of Ecology, Evolution and Natural Resources at Rutgers University.

But in some areas, multiple threats “are coming together as a sort of a perfect storm,” she said. “There are too many different problems all converging at the same time in the same place, and the multiple effect makes the situation all the more serious.”

These threats, experts say, include suburban sprawl, the impact of marauding invasive plants and insects, climate change and not only acid rain but also, contrarily, lack of rainfall. But in many locales, the implacable browsing of deer on young trees is killing replacement saplings, depleting shade and promoting the growth of invasive plants that smother native species.

So some forests are increasingly a Potemkin village concealing a subtle, but devastating, transformation. “Many of the forests in this area are old-age homes, full of aging trees that have no offspring nearby,” said Leslie Jones Sauer, author of “The Once and Future Forest,” an influential guide to forest restoration.

But while nursing homes for people will survive, “we may be seeing the last generation of these trees,” she said.

And while the forests themselves are not going to die, Mr. Schulze said, “a degraded forest could have large impacts on water quality, and habitats for wildlife in the forests.”