Southern Pine Beetle Outbreak in New Jersey: Another Example of Why Forests Should be Managed
A large faction of the American public has become convinced that the only way to
conserve our prized forests on public lands is to stop harvesting, prevent wildfires, and restrict or
exclude forest management. Too often this “lock it up and let it go” mentality can have
unintended, disastrous consequences, as demonstrated across the nation in recent years. The
extensive mountain pine beetle (Dendroctonus ponderosae) outbreaks in lodgepole pine (Pinus
contorta) forests of the western U.S. and Canada, the bark beetle outbreaks in ponderosa pine (P.
ponderosa) forests of the Black Hills of South Dakota, and, most recently, the catastrophic
wildfires in Arizona are examples. Add southern pine beetle (D. frontalis) outbreaks in Texas
(1975-1993), Tennessee (2000-2001), and now New Jersey to this growing list.
As its name suggests, the southern pine beetle (SPB) is a major pest of southern pines
from Texas to North Carolina. But who ever thought the beetle would become a major problem
in New Jersey? Prior to 2001, the last known SPB outbreak of any magnitude in NJ occurred in
1930. But, beginning a decade ago, SPB infestations began showing up at low levels in New
Jersey’s Pinelands National Reserve (formerly known as the Pine Barrens). The occurrence of
SPB attracted little attention until populations skyrocketed to unprecedented levels in 2010,
killing at least 14,000 acres of mostly pitch pine (Pinus rigida). The senior author visited the
infested area from the air and on the ground in early June and provided control recommendations
to the New Jersey Forest Service. He was impressed with how closely the current situation in
New Jersey resembled the SPB outbreaks in Texas he observed in the 1970s, 1980s and 1990s.
As did those in Texas, the New Jersey outbreak provides an excellent lesson for private forest
landowners wherever they may live: the best way to ensure a healthy forest is to manage it.
To understand the current problem, one must know some of the history of southern New
Jersey. Prior to being set aside as the Pinelands National Reserve in 1978, the 1.1 million acres
of pine/oak woodlands had been a productive, working forest since the 17th century. The first
white settlers were attracted by the growing whaling industry in 1650. Natural resources gave
rise to other important industries. People used bog iron for cannonballs and household goods,
sand for glass (including the first Mason canning jar), and wood for ship building, charcoal,
lumber, paper, and cordwood. Shipbuilding began in 1688 and continued until the 1900s. Low
lying areas were converted to commercial cranberry bogs as early as 1830, while blueberry farms
not controlled, the beetles threaten vast areas of pure pitch and shortleaf pine on the Reserve in
the central part of the state.
Mild winters since 1995 are believed to have been a contributing factor to the SPB
outbreak (Matt Ayres, Dartmouth College, personal communication). Southern pine beetle at the
northern extent of its range is killed by very low winter temperatures. Studies by Ayers and his
students have shown that 50% of the beetle population will die if winter temperatures reach 0° F
and more than 90% will not survive if air temperatures drop to -7° F.
Unfortunately, due to recent changes in climate, such temperatures have become rarer in
the NJ Pinelands during the last 50 years. Since 1995, for example, winter temperatures have
dropped below 0° F in the Pinelands during only one winter (2004) (Matt Ayres, personal
communication). This warming trend has favored the buildup of SPB populations. But other
factors, particularly the age (many trees are over 80 years old) and abundance of pine stands,
coupled with the lack of both forest management and beetle control, are believed to be primarily
responsible for the unprecedented outbreak in this state. Interestingly, the same mild winter
temperatures in neighboring Delaware have not led to a SPB outbreak in this state’s pine forests,
nor did above-average winter temperatures in New Jersey for seven consecutive years in the
1970s. Delaware foresters are quick to point out that the difference is that forests in their state
are kept healthy through forest management (periodic thinning, harvesting, and regeneration).
The lesson being learned in New Jersey about what happens when management is
withheld from working forests is not new. Texas gained its first hard-knock experience with
SPB outbreaks on pine-dominated preserve areas in 1975-77 with units being set aside for the
85,000-acre Big Thicket National Preserve. Essentially all the mature loblolly pines (P. taeda)
on the Loblolly Unit and a large portion of those on the Lance Rosier and Beech Creek units
were destroyed by uncontrolled SPB infestations.
Texas was slow to learn the lesson. In 1983-84, some 3,400 acres of unmanaged loblolly
pine were lost to SPB in the Four Notch area of the Sam Houston National Forest, being
considered at the time for wilderness designation under the RARE II process. The losses in this
case were largely a result of environmental activist interventio n that delayed timely control. A
similar SPB outbreak occurred in 1990-93 on newly-designated wilderness areas on the Sabine,
Angelina, and Davy Crockett National Forests. Over 40% of the pine type on wilderness was lost
to SPB in less than 3 years, including 7,500 acres on Indian Mounds Wilderness alone. In sharp
contrast, on non-wilderness areas of the National Forests in Texas, SPB killed less than 2% of
the pine type during the same period. The latter forests were managed and expanding SPB
infestations were promptly controlled by means of salvage and cut-and- leave.
date back to 1916; these two fruits remain the principal agricultural crops in southern New Jersey
The large resource of shortleaf (P. echinata) and pitch pines supplied local paper and
sawmills up until the mid 1970s. Environmental restrictions enacted in the late 1970s that
preclude cutting trees have since driven these industries out of the state.
The Pinelands harbor 43 endangered and threatened species such as the Pine Barrens tree
frog (Hyla andersonii), Pickering's morning glory (Stylisma pickeringii var. pickeringii), and
bald eagle (Haliaeetus leucocephalus). The area was originally recognized as of value for
another critically important resource – water. Beneath the Pinelands lies a huge natural reservoir
– the Kirkwood-Cohansey aquifer system. It extends over 3,000 square miles and holds 17
trillion gallons of water, enough to cover New Jersey in a lake 10 feet deep. Efforts to protect
this region’s primary source of drinking water began in the 1950s and 1960s. John McPhee’s
1967 national best-selling book The Pine Barrens generated outcry to protect the Pinelands.
In 1977, casino gambling began in Atlantic City, increasing development pressure on the
nearby Pinelands. In response to threats of harvesting and development, Congress established
the 1.1 million-acre Pinelands National Reserve – the nation’s first such designation – in 1978.
In the following year, the New Jersey Pinelands Commission was created to administer the
Pinelands Reserve. The Commission has 15 members, including representatives from the state,
seven counties, and one federal agency. In 1983, the Reserve was designated a U.S. Biosphere
Reserve by UNESCO, an agency of the United Nations. Over 53 percent of the land in the
Pinelands National Reserve is permanently protected from development.
The dense stands of underbrush and pine are conducive for destructive wildfires. The
New Jersey Forest Fire Service (a separate agency from the New Jersey Forest Service) conducts
periodic prescribed burns within the Reserve to reduce fuel loads and is called upon to suppress
frequent wildfires. Other than prescribed fire, however, forest management is no longer
practiced on the Reserve.
To ensure protection of the National Reserve, strict environmental regulations have been
passed that affect not only the Reserve, but all the intermingled private lands as well. A permit
and Forest Stewardship Plan is required before a private landowner can manage his /her land or
fell trees, a process that can take from several months up to a year or more. As a result, the pine
forests on the Reserve have gone 30+ years with no thinning, harvesting, regeneration, or other
silvicultural practice, rendering a million acres as “beetle bait.”
The SPB outbreak in New Jersey, first detected in 2001, continues to expand a decade
later, primarily in mixed pine/hardwood stands in the southern part of the Pinelands Reserve. If
Contributing factors to the 1990-93 SPB outbreak on wilderness areas in Texas included
lack of recent forest management, abundance of older, susceptible pine stands, environmental
activist pressure to do nothing, environmental regulations that precluded cutting trees for beetle
control on wilderness, and favorable environmental conditions. Sounds much like the situation
in the Pinelands of New Jersey today!
Until federal policies change to allow more aggressive forest management, there may be
little that can be done to avoid insect and disease outbreaks and devastating wildfires on
wilderness, preserve, and park lands. But, private forest landowners can take measures to avoid
these resource losses through sound forest stewardship. Products from a managed forest will pay
the costs associated with maintaining forest health. Also, forest management allows owners to
conserve aesthetic values, protect watersheds, and avoid abrupt and catastrophic changes due to
wildfires and/or beetle outbreaks. The take-home message is “a managed forest is a healthy
forest,” or in bumper-sticker brevity: “Use it or lose it!”
*Ronald F. Billings (email@example.com), Ph.D., CF, is Manager, Forest Health, Texas Forest Service, 301
Tarrow, Suite 364, College Station, TX 77840; Bob Williams (firstname.lastname@example.org) , RPF, CF, is consulting
forester and Vice President of Forestry Operations, Land Dimensions Engineering, 6 E. High Street, Glassboro, NJ
Submitted to Society of American Foresters for publication, 20 June 2011.