Silas Little Experimental Forest

The Silas Little Experimental Forest is an international destination for innovation in wildland fire science and field experimentation, next generation fire behavior modeling, and monitoring of forest conditions and the ecological effects of disturbance and management. In addition, the experimental forest is a key location for training, demonstrations, and workshops focused on providing managers, students, researchers, and policymakers to tools, knowledge, networking connections needed to advance the use of prescribed fire, fire planning, and forest ecological forest management and monitoring with the best available science. The program is aimed to be responsive to the challenges of both present and future, with a particular focus on the science of wildfire management, prescribed burning, and forest disturbances. Work also includes studies investigating the carbon cycle, climate change, invasive forest pests, ticks, carbon management, and ecological diversity. We address these needs via interdisciplinary partnerships and the use of technological and computational innovations of recent decades including terrestrial and airborne LiDAR, multispectral scanning platforms, eddy flux towers, custom fire behavior monitoring equipment, next generation fire behavior models, machine learning, and analyses of big data.

The Silas Little Experimental Forest is also a key training and demonstration resource for prescribed burning and related science. Each year, experimental forest staff engage directly with hundreds of students, researchers, wildland fire practitioners, policy makers, and conservationists who visit for field trips, workshops, trainings, or independent technical transfers or consultations. Often, the objective of these engagements is to transfer and demonstrate the latest science of prescribed fire and fire ecology, technical approaches, and decision support tools to managers. Additionally, these activities foster innovative ideas in science and management, community development, and inclusivity, through engagement in field experiences.

The New Jersey Pine Barrens is often first in the list of examples of a pyrogenic landscape, or one that is naturally adapted to burn in wildfires and prescribed fires. Fire-adapted pitch pines, oaks, and understory shrubs of the heath and laurel families provide critical habitat for rare and endangered species as well as a highly combustible fuelbed on the edge of Philadelphia and New York suburbs. Here, nearly 1,000 wildfires burn approximately 10,000 acres of forest each year, with nearly each occurring at or impacting the wildland urban interface. However, over twice as many acres are treated proactively to meet public safety and ecological forest management goals, as a key component of keeping the Pine Barrens and its residents safe and healthy. In between these flammable uplands, Atlantic White Cedar and Red Maple Swamps follow the many freshwater streams eventually out to the Atlantic Ocean and support a diverse selection of flora and fauna as well.

Wildfire and intentional burning have been constants on since before European settlement on this landscape. The origins of the Silas Little Experimental Forest (formerly the Lebanon and Ockinickon Experimental Forests) are rooted in the post-industrial Pine Barrens of the late 1800s and early 1900s when rampant wildfires burned forests degraded by 2 hundred years of cutting for the iron, glass, and charcoal industries every 4-8 years and were a focus of Gifford Pinchot's nearly decade long study of the landscape. Railroads had also become a major ignition source; and, collectively, wildfires impacted tens of thousands to hundreds of thousands of acres almost every year. Repeated intense fire on this landscape favors more intense fire as flammable species are usually only top killed, and resprout into more flammable forms. By the 1920s, cranberry farmers and railroads had established histories of treating their ground annually with prescribed fire to reduce fuels; however, burning on state land was unacceptable and very controversial due to presumed negative impacts on timber value, fear of escapes, and doubt in its abilities to reduce wildfire.

The fire and forest problems of this landscape were typical of much of the Mid-Atlantic and Northeast in the early 1900s, and early research at the Experimental Forest aimed to respond to this need with studies focused on prescribed fire and forest restoration. With onsite forest composition of chestnut oak, white oak, scarlet oak, black oak, shortleaf pine, pitch pine, in the uplands; and Atlantic white cedar, red maple, and black gum in the wetlands, the Silas Little Experimental Forest's location was ideal for fire and forestry experiments that could be informative of this landscape and others of similar compositions.

Today federal, state, county, and private prescribed burning groups take on an all-hands-all-lands approach to managing the New Jersey Pine Barrens resource, collaborating and cooperating as partners in a community of practice fire management, research, and training. Research products of these partnerships have included new tools for quantifying fuel hazards and predicting fire behavior as well as new knowledge about how prescribed fires help support carbon storage objectives, restore forests impacted by invasive insects, and can increase diversity of insects and forest structure while reducing disease carrying ticks.

Climate

The climate on the Silas Little and surrounding Lebanon State Forest is strongly influenced by the Atlantic Ocean. Elevations are so uniform in this area that they do not influence temperature and there is only slight variation from one site to another. The coldest month is February (-2 to 1 °C) and the warmest is July (23 to 25 °C). The first killing frost occurs about October 18 and the last about April 22. The high summer maximum is 42 °C and the lowest winter minimum is -32 °C. Rainfall is relatively constant and equally distributed both as to season and location, but there is a marked dry season in the fall. Average rainfall in this area is 1,145 mm. Snowfall is slight and remains on the ground only a short time.

Soils

Soils in the region of the Silas Little are described as Englishtown formation, consisting of micaceous white and yellow quartz sand and glauconitic, and locally lignitic lens of clay and silt. Southern New Jersey is essentially an immense coastal plain, generally less than 30.5 m above sea level; average elevation is 18 m. Rivers in this area drain southeast to the Atlantic Ocean. The region’s soils are predominately sandy but vary considerably in texture, ranging from course sand to sandy loam, and also vary in drainage. The dry character of much of the soil adversely affects plant growth during even to moderate drought.

Vegetation

The Silas Little represents the Pine Barrens forest types that include poorly drained soils supporting pitch pine (14 percent), infertile sands supporting pitch pine and low-grade oaks (22 percent), swamp forests (12 percent), and slightly better quality soils supporting oaks and shortleaf and pitch pines (52 percent).

The Silas Little Experimental Forest is situated within the large, continuously forested and ecologically significant New Jersey Pine Barrens landscape. This location is less than 30 minutes from I-95, 60 minutes from Philadelphia and Atlantic City International Airports, 75 minutes from Newark International Airport, and 100 minutes from New York City. Field offices of key partner agencies are located within 15 minutes of the Experimental Forest: New Jersey Forest Fire Service, New Jersey Forest Service, US Department of Defense Joint Base McGuire-Dix-Lakehurst and Warren Grove Gunnery Range, US Fish and Wildlife Service, and multiple private and non-profit organizations.

The Experimental Forest itself consists of 592-acres primarily of mixed oak-pine forest containing tree species typical of the Mid-Atlantic Coastal Plane and other areas of the eastern US. The experimental forest is the home base of two long-term eddy covariance flux sites in the New Jersey Pine Barrens, each of which are embedded in a 3 km x 3 km network of long-term biometric plots that use the Forest Inventory and Analysis Phase 3 design. One of these flux sites (Silas Little) is on the Experimental Forest, while the other (Cedar Bridge) is at an outlying location approximately 20 miles east in New Jersey’s Greenwood Wildlife Management Area, in a pitch pine – scrub oak forest. The experimental forest features multiple forest structures and environments reflective of management, ranging from the historic pitch x loblolly pine hybrid breeding plantation to research areas of contrasting fire histories and invasive insect damage. Numerous other outlying field sites of the experimental forest are also easily accessible within 30 minutes.

The scientific program of the Experimental Forest is supported by a main office building and multiple outbuildings that provide office, laboratory, classroom, and workshop space for US Forest Service researchers and their partners. Permanent staff at the experimental forest consists of two scientists and one technician, with additional term employees, student researchers, and on-site partners comprising a larger team. Forest roads passable by most vehicles and a network of trails provide easy access for people and research equipment to most areas of the experimental forest.

Research, Past and Present

In 2002, a 5-year National Fire Plan grant was awarded for a study entitled, “Regional climate and fire danger modeling specific to the Pine Barrens,” to carry out research to enhance the National Fire Danger Rating System in the Pine Barrens. This research will develop a more responsive fire danger rating system that is specific to the New Jersey Pine Barrens by focusing on the interaction between climate, fire, and vegetation. The research will employ prescribed burns and the use of portable and fixed flux towers to monitor vegetation, soil, and atmospheric conditions before and after prescribed burns over a range of conditions and vegetation types. The network of fire weather stations and portable towers should produce detailed fire weather and carbon, water, and energy flux measurements at local and landscape levels to determine the processes that are distinctive for the Pine Barrens.

Earlier research (started 1985 to 2002) has been carried out by the staff and graduate students at the Pinelands Research Station. Researchers are looking at the effects of fragmentation and human-induced changes in hydrology of the Pineland wetland ecosystem on the Atlantic whitecedar swamps. Studies on the effects of acid deposition on the New Jersey Pine Barrens include a monitoring station for the New Jersey Atmospheric Deposition Program. Other studies deal with stream chemistry, the effects and recovery from past fires in the Pine Barrens, inventory and population dynamics of wildlife species, and several other problems unique to these sandy sites along the Atlantic Coast.

Major Research Accomplishments and Effects on Management

The result of early work during the Silas Little era was science on the role and reductive effects of frequent prescribed burning on surface fuels and the landscape-scale strategy of burning a loose checkboard pattern across the landscape to reduce wildfire potential and facilitate suppression. Other, associated research included research on the timing and use of fire and herbicides to accomplish silvicultural objectives. Later he was instrumental in breeding the pitch x loblolly pine hybid, the "loblollies of the north" that bring loblolly's form and growth rate into the Mid-Atlantic and Northeast while taking advantage of pitch pine's frost tolerance and rust resistance. This tree was also key in reforesting Korea in the 1970s after decades of overharvesting. It is still widespread there today. He also wrote multiple chapters in the text Pine Barrens: Ecosystem and Landscape, which has been instrumental in guiding preservation and management in the Pine Barrens for over 4 decades.

Recent accomplishments of the program stem from modern fire research, forest carbon and process studies with the experimental forest's carbon flux sites, and ecological studies. Over the past 2 decades, research has shown that despite "spending" a little carbon by prescribed burning the net long-term effect is a gain in stored carbon and a more fire resilient forest with greater structural diversity. This contrasts with the effects of invasive insects, which tend to attack overstocked forests, and tend to perturb carbon uptake at the decadal scale. At the same time, the program has planned and implemented numerous prescribed fire experiments that have informed on the physical interaction processes of combustion and fluid dynamics at the fireline and provided critical data for testing and refining new physics-based fire behavior models. This work has also resulted in new information about embers, such as how many occur and where they land.

This program is also a leader in the development of new terrestrial laser scanning approaches for measuring fuels and fire effects. Using multiple scanning platforms, the program has successfully demonstrated how terrestrial laser scanning can more rapidly and effectively inventory fuels with greater richness and accuracy than traditional methods to identify fuel hazard around communities and quantify the effects of prescribed fire or mechanical treatments. The team is now expanding this work within northeast, southeast, Pacific Northwest, and internationally.

Other impacts of this work can be seen in its engagement and leadership in fire community groups, such as the North Atlantic Fire Science Exchange, the Northeastern Wildland Fire Cohesive Strategy, and with numerous universities and communities of practice. Through these connections, the Silas Little Experimental Forest leverages a co-production strategy to conduct the scientific process from start to finish with managers, and provide frequent technical transfer and advising that helps guide management policy, strategy, and actions that are based in the best available science.

Research Opportunities

Opportunities are nearly unrestricted in all aspects of fire weather, wildfire ecology, and carbon sequestration research. New research within the New Jersey Pine Barrens region is encouraged and facilitated by Forest Service and Pinelands Research Station scientists. Research at Silas Little  requires approval of the Forest Service program manager.