Ecologists learn from scars of 1995 Long Island blaze Earlier success in halting fires allowed big buildup of fuel, ecologists say

September 22, 1996|By NEW YORK TIMES NEWS SERVICE

NEW YORK -- The charred trees were still smoldering in late August last year, when a handful of scientists got down on their hands and knees in the heart of the pine barrens in Westhampton to study the regeneration of the pitch pine.

This contorted little pine, which has evolved with fire over thousands of years, has serotinous, or resin-sealed, cones that need fire to open and release its seeds.

But last year's fire - which swept through 5,500 acres and burned a dozen houses before 2,200 firefighters could bring it under control - was so intense in some places that many dwarf pitch pines burned to a crisp before they could even open their cones. And a year later there are very few seedlings beneath these dead trees.

It is one of the striking observations that ecologists have made after spending a full year observing the regrowth. But perhaps most striking is their conclusion that the severity of the fire was, at least in part, a result of Long Island's past success in putting out and preventing fires in the pine barrens.

Debris piles up

Because there had been so few small fires over the last 60 years, debris piled up beneath the dwarf pines, providing huge amounts of tinder that wouldn't otherwise have been available. Moreover, the lack of fires meant that the forest was filled with older trees near the end of their life span and thus less able to recover from the blaze.

"For decades, people have been conditioned to think that fire was bad, dangerous, as in Smokey the Bear," said Dr. Marilyn Jordan, an ecologist for the Nature Conservancy, who was in the pine barrens three days after the fire. "But now we are finding that if we don't develop a management plan for more frequent, controlled fires, the pine barrens and the ecosystem it supports will suffer."

Controlled burning, as opposed to instant fire suppression, has been debated for years in other places, including Yellowstone and other national parks and wilderness areas. Even on more populous Long Island, ecologists say that controlled burning in the pine barrens - even starting fires on purpose to burn away undergrowth before it builds up - would both encourage new growth and prevent dangerous wildfires.

Right after the fire, Jordan observed many trees operating according to nature's plan, as thousands of gossamer seeds floated down from their open cones onto the mineral-rich ash that had been, just a few days before, an impenetrable mass of huckleberry, blueberry and scrub oak.

These areas had not burned so intensely. And a year later, they are thick with 2-inch seedlings. It's the difference that scientists find so revealing.

"In the most severely burned areas, the fire apparently burned up the cones and seeds," said Dr. Jessica Gurevitch, an $H associate professor at the State University at Stony Brook, standing by a lifeless pitch pine recently.

"We're seeing relatively few seedlings in these areas, compared with the scorched areas, where they are relatively abundant."

Gurevitch has a $25,000 grant from the National Science Foundation and $7,000 from the Nature Conservancy to track the regeneration of this ecosystem, and two of her graduate students, Wei Fang and Daniel Taub, have spent the last year tagging 6,000 seedlings to monitor their growth and survival rates.

Recently, they walked along the perimeter of the burned area, where the fire had been less intense, and the fresh young leaves of bearberry already coursed along the ground. Whole stands of Houghton's umbrella sedge, listed as rare in New York state, flourished in the spaces opened up and fertilized by the fire. And beneath the branches of the scorched pitch pines, whose cones had opened according to plan, were sprinklings of 2-inch emerald-green pine seedlings, growing as thickly as 30 to 100 per tree.

But in the severely burned areas, there were only 3 to 5 seedlings per tree, or none at all if the trees had been killed by the fire.

"The severity of the fire was due to the fuel - the dead branches and pine needles that had built up over the years," said Susan Antenen, director of science and stewardship of the Long Island chapter of the Nature Conservancy. "By suppressing fire for 60 years, it's going to be more intense than frequent fires. And because the fire is hotter, the serotinous cones get burned, so there are fewer seeds to start the whole cycle of growth."

'10 feet of continuous fuel'

Antenen led the way into an area that had escaped the fire altogether. It was a nearly impenetrable mass of high-bush blueberry, dwarf pines and 10-foot-high scrub oak, which was loaded with dead branches. She pointed to a virtual nest of old pine needles piled up in the branches of a pitch pine looking like a pile of tinder waiting for a match, and said, "We're standing in 8 to 10 feet of continuous fuel."

Many of the pitch pines that were burned have not been resprouting from their trunks and branches, as this fire-adapted species should. They are simply too old.

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