Suffolk's beetle-ravaged pine barrens at heightened wildfire risk, foresters say

Thousands of acres of trees have been killed by the southern pine beetle in the 10 years since they arrived in Suffolk County, foresters say, heightening the risk of wildfires by generating heavy fuel loads that can drive bigger, hotter fires.

"There's been a progression toward more severe fires," said Capt. Timothy Byrnes, a forest ranger with the state Department of Environmental Conservation based in Stony Brook, largely "due to the infestation of the pine beetle."

The beetles have ravaged forests from the Rocky Point Preserve to Southaven County Park in Yaphank and as far east as Napeague State Park in East Hampton. Infestations have also reached Fire Island. Their favorite target is the pitch pine — the most common species in the pine barrens, 100,000 acres of ecologically sensitive private and public lands in eastern Brookhaven, southern Riverhead and western Southampton.

"Thousands, if not tens of thousands, of trees have been lost" in the far East End, said David Lys, an East Hampton town councilmember. "It’s very devastating."

The towering stands of dead pines don’t by themselves increase wildfire risk, according to Kathy Schwager, natural resource and fire program manager at Brookhaven National Laboratory in Upton, which is surrounded by 5,000 acres of pine forest. "You open up the canopy and all of a sudden you have this flush of growth" — plants growing lower to the ground — in the forest's understory.

"What creates really intense fire conditions is the small-diameter fuel," Schwager said. "That's what makes that fire go."

LA calamity

As wildfires that consumed whole neighborhoods in Los Angeles continue to burn, experts have labored to explain how the calamity unfolded. One significant factor, according to climate scientists, was an oversupply of combustible fuel in and around the city: Two wet winters generated a burst of growth, then months of drought turned it to tinder.

The Eastern Seaboard has never been as vulnerable to wildfire as the arid regions of the Southwest and West Coast, and it lacks factors like the swift Santa Ana winds that have blown embers to ignite new fires in the mountains surrounding Los Angeles.

But Long Island, like LA, has been hotter, and alternately wetter and drier, than the patterns that were once normal. And this region shares the risk factor of the buildup of combustible fuel in forests — the unwelcome contribution on Long Island of the tiny invasive insect.

The beetles are themselves a signal of climate change. They are native to the southeastern United States, but as winters warm, they have slowly spread north. They were first spotted on Long Island in 2014, in the Wertheim National Wildlife Refuge in Shirley, Ann Marie Chapman, the refuge’s visitor services manager, said during a walk in the woods in November. The insects may have blown in from New Jersey during Superstorm Sandy, Chapman said. Infestations have now spread as far north as Cape Cod.

The beetles are tiny, just one-eighth of an inch long, but destructive. The adults crawl into tiny crevices in the bark of a pine tree and tunnel into the cambium, the layer just underneath the outer bark, preventing nutrients from traveling along the trunk. Females place a pheromone call to other beetles nearby, inviting them to a choice tree; they then lay eggs under the bark, overwhelming the host with thousands more invaders.

Pines try to defend themselves by flooding the tunnels with sap and expelling the insects. But trees that are stressed are more susceptible, and even healthy trees will succumb to a full-blown infestation, usually dying in a matter of months.

Pine barrens' overcrowded understory

The pine barrens are well adapted to wildfire: pitch pines are armored with thick bark that protects them from scorching, and their cones open to disperse their seeds when exposed to high heat. Native shrubs such as laurel and huckleberry spread through tough underground rhizomes so they can sprout again even if the plant is charred. Naturally occurring low-intensity fires help keep the ecosystem healthy, thinning trees and shrubs, leaving those that remain to flourish.

But for many years those occasional flare-ups were suppressed, and the pine barrens became choked with trees and shrubs.

"The forests are too dense and the trees are unhealthy," Schwager said. In the pine barrens’ sandy, nutrient-poor soils, crowded trees become stressed, "which makes them more susceptible to disease and pests."

When the beetles arrived, they found "the perfect conditions," she said.

"So many people worked to preserve the pine barrens," Chapman said, "and along comes an insect the size of a grain of rice to wipe it all out."

Failed 'preemptive strike'

Today, Napeague State Park on the South Fork is among the worst-hit areas on the Island. The state parks department conducted "suppression cuts" when the beetles were first detected there, as a kind of "preemptive strike," said Tim Watson, director of the Montauk complex of state parks. That effort failed to stop the spread, Watson said. Aerial photos of the park show sweeping stands of pines whose needles have turned rusty brown and gray.

Hotter, drier weather increases the chances that the understory — and in extreme drought, the standing dead trees as well — ignite. Last year was the hottest on record in New York, as well as in the United States and across the globe, according to the National Oceanic and Atmospheric Administration.

The coastal New York region experienced 10 more "fire weather days" — days that are hot, dry and windy — in 2023 than in 1973, according to an analysis by the nonprofit Climate Central. That’s among "the biggest increases in fire weather that we've seen on the East Coast in the last 50 or so years," said Kaitlyn Trudeau, Climate Central’s senior research associate for climate science.

Long Island's riskiest season for wildfires is springtime, when humidity is low and swift winds blow, igniting the understory as it goes, Schwager said.

The particular geography of the narrow South Fork would make a large, spreading wildfire in Napeague particularly hazardous to human life. "There's one road in, one road out," Lys said. And that road runs right through Napeague and its neighbor, Hither Hills State Park. If Napeague burns, "Montauk would be on an island" without an escape route.

State foresters are working on a "multiyear strategy" to manage the extra fuel load, Watson said.

In the meantime, Brookhaven National Lab cut down and burned dead trees to restore part of the damaged forest. "We have widely spaced trees and lots of wildflowers coming in and grasses and tons of pollinators," Schwager said. 

The beetles are still chewing through the pitch pines, and climate experts expect 2025 could set another record for heat. But Schwager said the lab's woodland revival effort offers a chance to consider: "What do we want to see, and how do we get there?"