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In Search of Prehistory

Not totally pristine, the pine barrens is the closest thing we have to a natural museum

By Dan Fagin | Staff Writer

Up on Bald Hill in the Manorville-Riverhead hills, where Long Island's last wilderness climbs the bouldery ridge laid down by an ice sheet a thousand generations ago, the pine barrens forest seems exquisitely undisturbed, even primeval.

But very little about the pine barrens is exactly what it seems. For while the 100,000-acre collection of dry plains, stunted forests, grassy marshes and flower-ringed ponds is the closest thing we have to a living museum of natural history, it is an imperfect representation of prehistoric Long Island - if indeed that were possible.

The scrubby pine forests of south-central Suffolk County were only one of several kinds of forests that once blanketed Long Island. Researchers now believe that centuries of farming, lumbering and fire-setting - by American Indians and European settlers alike - actually expanded the pine barrens by removing other types of forests that were more economically useful.

``Long Island was settled so early, and so much of it was cut and burned and plowed for so long, that there's not many vestiges left,'' said Marilyn Jordan, a stewardship ecologist at the Nature Conservancy of Long Island. ``You can't turn back the clock and go back in time.''

Scientists have very little to go on as they try to reconstruct the history of the pine barrens, and even less for the denser forests of oak, chestnut, hickory, tulip, birch and other hardwoods that probably once dominated much of Long Island.

What little they do know comes from studying the early maps and reports of colonists and from analyzing fossilized pollen from trees and plants.

Nature never stands still, of course, which makes the researchers' task even more difficult. Pine forests have probably existed in North America for tens of millions of years, but any local trace of them was wiped out by the massive glaciers that scoured the Long Island landscape at least twice within the past 150,000 years. When the last ice sheet retreated north about 20,000 years ago, it left behind a frozen landscape in which practically nothing could grow.

Pollen specialists such as Les Sirkin, a research professor of earth sciences at Adelphi University, have reconstructed what happened next by studying microscopic pollen buried deep in bottom sediment of local lakes and peat-filled bogs.

In the oldest sediment, deposited just after the glacier left, Sirkin has found pollen from cold-weather herbs and grasses, not trees. As the weather warmed, spruce and fir forests became dominant, followed by pine and then oak and other hardwoods as temperatures leveled off about 6,000 years ago.

But while hardwoods grow well on the northern half of Long Island, conditions are different to the south, especially in Suffolk County.

There, rivers of melting ice from the departing glacier dumped a thick layer of sand and gravel that is low in nutrients and doesn't hold water well. Fires spread fast and far on the dry soil, and there aren't many creeks or wetlands. Taller, stronger hardwood trees generally won't grow, and neither do many crops, so the European colonists mostly avoided the hardscrabble pinelands they considered ``barren.''

It's a good thing they did, because the land they shunned sits above Long Island's last large reservoir of clean drinking water, as is a treasure trove of species found in few other places.

Through centuries of natural selection, or survival of the fittest, plants and animals in the pine barrens have adapted ingeniously to the harsh conditions. Local plants such as the bladderwort and the thread-leafed sundew eat insects to get the nitrogen and phosphorus that isn't available in the poor soil. Adapting to the tinderbox conditions, the globally rare twisted dwarf pines of Westhampton developed cones that open to disperse seeds only in the intense heat of a fire. Swamps of rare Atlantic white cedars thrive here, and so does Hessel's Hairstreak, an endangered butterfly that lives only in those cedar swamps.

The plants and animals adapted so well, in fact, that pine barrens species moved in to fill the void when the hardwood forests were destroyed by lumbering, and when the richer soils were exhausted by intense plowing. That has led a few botanists to suggest that the pine barrens is merely a scavenger ecosystem that owes its existence to human intervention.

Most researchers, though, believe that at least some parts of the pine barrens are indeed prehistoric, particularly areas near Moriches and Westhampton where soil conditions are worst. Traces of ancient charcoal, as well as pine pollen, suggest that pines and forest fires have been here for ``at least four or five thousand years,'' said Ray Welch, a professor of biology at Suffolk Community College.

A pristine window into Long Island's past? Not quite. But the pine barrens, Welch said, ``are as similar to what you would have found primevally on Long Island than anything else you can see now.''

In other words, they're the best we've got left.