RWU-NRS 4155

Experimental Forests


Last modified 08/07/2006

by Tim Stone

Silas Little Experimental Forest

New Lisbon, New Jersey



  • Introduction
  • Climate
  • Soils
  • Previous Research
  • Current Research
  • Location
  • Suggested Reading
  • Contact Address

    The Allegheny Forest Experiment Station was established in 1927 to "Coordinate research work already underway by forestry schools, States, industries, and private owners, and to conduct research in fields and on problems not already covered", with "experimental areas established (1) in Huntington County, Pennsylvania; (2) in southern New Jersey; (3) on the Eastern Shore of Maryland; (4) in Maryland betweeen Baltimore and Washington; and (5) in the Allegheny National Forest".

    The history of the Silas Little Experimental Forest probably should start with the establishment of Camp Ockanickon in 1927 in Aerial view of Silas Little EFOcean County, New Jersey. By 1933, because of increased recreation pressures at Camp Ockanickon, the Experiment Station and the Board of Conservation and Development, State of New Jersey signed a Cooperative Agreement for a new location in adjacent Burlington County. The State placed at the disposal of the Station 591 acres "for the purpose of conducting studies, experiments, and demonstrations in silvics and silviculture.... to solve forest problems of the region typified by conditions in southern New Jersey. These may include experiments in obtaining natural reproduction of the forest after cutting, in thinning to stimulate growth, and in artifical reforestation; also, more fundamental studies of the factors which affect tree growth". In the next few years the Station constructed, or moved to the site, several structures for office/storage/living space. The site was initally known as the Lebanon Experimental Forest because of its location on the Lebanon State Forest.

    Permanent yield plots at Camp Ockanickon in 1927 were maintained, as were underplantings of conifers. Weather records started at this site in 1927 were discontinued and two new weather stations were established at the Lebanon Experimental Forest.


    In 1937 Dr. Silas Little, Jr. was assigned to the Forest and worked there until his retirement in 1979, most of that time as the research project leader. During those 43 years Dr. Little produced over 100 publication. In the late 1970's the Forest was turned over to the Genetics Project in Durham, New Hampshire and several technicians maintained orchards and plantings on the site. In 1985, following the departure of the last Forest Service employee, the Station entered into a cooperative agreement with Rutgers University to use the buildings for a Pineland's Research Center. The Pineland's Center has a full-time director, a site manager, and a number of graduate students in residence. In the late 1980's the site received recognition as a Man and the Biosphere (MAB) site and National Science Foundation grants have permitted Rutgers to purchase several laboratory buildings. Several office trailers at the administrative site, as well as some greenhouse space, are used by the New Jersey Department of Agricultural, Bureau of Biological Pest Control, for offices and research purposes.


    The climate on the Silas Little Experimental Forest, 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 (29-34o F) and the warmest is July (73-77o F). Radiation cools off the plains and bogs resulting in early and late frosts. The first killing frost occurs about October 18 and the last about April 22. The high summer maximum is 107o F and the low winter minimum is -25o F.

    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 45 inches. The dry character of much of the soil can adversely affect plant growth during a moderate drought, which, with a moister soil, might not be as serious. Snowfall is slight and remains on the ground only a short time.


    Pine Barrens on the Silas Little EFThe southern interior of New Jersey is essentially an immense plain, generally less than 100 feet above sea level. The Experimental Forest probably averages 60 feet above sea level. Rivers in this area drain southeast to the Atlantic Ocean. The region known as the "Pines" is predominately sandy, but varies considerably in texture, ranging from a course sand to a sandy loam, and also varies in drainage. The Pine Barrens, which probably represents conditions on the Experimental Forest, includes swamp forests (12%), poorly drained St. Johns soils supporting pitch pine (14%), infertile Lakewood sand supporting pitch pine and low grade oaks (22%), and slightly better quality sassafras sand supporting better growth of oak, shortleaf and pitch pine (52%).

    This region is described as the Englishtown Formation consisting of micaceous white and yellow quartz sand and glauconitic, and locally lignitic, lens of clay and silt in places. This formation thins toward the southwest from about 160 feet in central Ocean County to less than 20 feet in Salem County.


    A major project begun in 1928 was designed to look at the silvicultural characteristics of species, and silvicultural practices to be applied in producing desired second-growth stands of the oak-pine type. There are 4 million acres of the oak-pine type in the Station area. Large contiguous stands of this type occur in New Jersey and in the late 1920's they were considered to be in a highly degraded condition with need of rehabilitation - by intensified fire protection and by aggressive stand improvement work, including interplanting. The chief native species were pitch and shortleaf pine and white oak. On land not recently disturbed, sweet gum and other hardwoods were an important part of the mixture.

    Repeated fires and cutting were responsibly for the poorly stocked stands of pitch and shortleaf pine and hardwood coppice. State policy at the time was to remove the hardwood in favor of planted conifers.

    The scope of this study included: reproduction by seed of the major species, including seed production, loss of seed by predation, seed bed requirements, seed germination and seedling survival; various levels of cutting to encourage seedling reproduction; reproduction from sprouts; conversion of repeatedly coppiced stands to mixed stands of high forest and coppice. Forty trees of seed-bearing age of the 11 principal species found on the Lebanon Experimental Forest were selected for long-term observation of time of flowering, leaf and fruit development.

    The consensus at the time was that any rehabilitation of sprout stands of the oak-pine type had to be based on the introduction of seedlings. Some of the reasons given were danger from decay in sprout-origin trees, failure of some stumps in each generation to sprout, and a tendency of sprouts to become prostate. Results were generally negative following an 8-year study of regeneration of oak with seedlings. While the research did not indicate how to get satisfactory seedling numbers it did produce useful information about conditions which mitigate against germination and survival.

    To validate the State's policy of favoring pine over hardwood by planting seedlings the Station planted seed under varying degrees and kinds of root competition which, from previous studies at Camp Ockanickon, was the most critical factor in growth of seedlings. Soil and litter were also varied. Between 1931-1933 the Station also planted pine seedlings in open areas of old cut-over and burned hardwood stands. Additional plots were cleared of all brush, fenced against rabbits, and planted with white pine (P. strobus), red pine (P. resinosa), jack pine (P. banksiana), loblolly pine (P. taeda), shortleaf pine (P. echinata), pitch pine (P. rigida), and Virginia pine (P. virgiana) on areas of sprout hardwoods that had been cut and burned 10 years earlier, on cleared land, and in thinned hardwood stands.

    In 1935, partly as a basis for establishing experimental plots to study conversion of coppice forests into mixed stands of high forest and coppice, a 2% line-plot survey was made of the Experimental Forest and 67 one-tenth-acre plots were established. In addition to stand data, elevations were recorded on each plot and along each strip line so a topographic map could be prepared.

    Oak regeneration after wildfire on the Silas Little EF

    The State Forester of New Jersey proposed a large study of the effects of fire in 1935 and the Station agreed to cooperate. A 30-year effort by the State had not solved the problem of protecting the oak-pine lands against periodically destructive fires. The obstacles to obtaining adequate funding for protection was lack of information about damage caused by fire. The more depleted the forest resource, the less the State was willing to spend on protection, and the less that was spent, the worse the depletion. One objective of the 1935 agreement was to evaluate damage from wildfires. Another objective was to compare losses from wildfires with the much lighter losses that were expected to occur from fires deliberately set under favorable conditions. The scope of this research included loss of wood and reduced productivity of the site, changes in water-holding capacity of litter and soil, and effects on wildlife.

    In 1938 the Station and the State of New Jersey met again and agreed to some new research goals for the Experimental Forest: fire effects and containment, regeneration of desirable species, economic surveys, and the possibilities of maintaining existing cedar swamps and restoring those converted to other species.

    Early surveys of Atlantic white-cedar swamps by Dr. Little indicated: 1. stands are essentially even-aged and a subclimax of the swamp hardwoods; 2. seedlings are present in great numbers (1 million/acre in mature stands) but seedlings older than one year are found only in understocked stands; 3. important factors against reproduction are flooding, insufficient light and seed supply; 4. open conditions, hummocks above water table, and seed from a stand of seed-bearing age within 2 chains are essential; 5. cedar starts to produce seed at age 3-4 giving it an advantage over hardwoods in capturing open sites. Major emphasis in 1941 looked at the possibilities of planting and direct seeding in cedar stands on the Experimental Forest. The State was interested in this problem because stands of 60-year-old cedar (in 1942) were worth $200-300/acre. Swamp hardwoods were worthless. The Station started a number of studies to look at the possibility of converting swamp hardwood stands to cedar by planting peat moss with stored seed and cutting or girdling overstory hardwoods.

    In 1948 the Station remeasured some hybrid pine plantings in New Jersey and Eastern Shore Maryland. This work led to interest in pine hybrids and a much larger program a few years later.

    High deer populations have always been a problem in regeneration of sprouts and seedlings in the Pine Barrens of New Jersey and in 1950 a number of studies were started to test the effectiveness of exclosures and repellants.

    By 1959 there was increased interest in hardwoods. Studies were initiated on soil-site in sweetgum stands, survival and growth of yellow-poplar seedlings, regeneration cutting in oak, and thinning in stands of several species of hardwoods. In 1963 the Station started studies on seed production in sweetgum and developed some new information on production and distribution of seed. Contrary to previous literatute, the number of fully developed seeds per fruit was relatively high. Fruits in these studies averaged 88 seed with 84% being sound. Based on seed production and distribution data the Station published recommendations on number of seed trees per acre.

    In 1964 the Station initiated a cooperative study with the State of New Jersey and the West Virginia Pulp and Paper Company to start a tree improvement program involving pitch and loblolly pine. The goals were: 1. produce a superior loblolly pine for southern Deleware and eastern Maryland, 2. produce superior pitch pine for sections of the Northeast, 3. develope pitch x loblolly pine hybrids that would be winter-hardy north of the loblolly pine range and that would outgrow pitch pine. Cooperators collected 30 outstanding parents of each species and grafted these in an orchard on the Experimental Forest. Pitch pine parent trees came from much of the natural range of the species while the loblolly parents were primarily from the eastern portion of the range of that species. The first F1 hybrids were outplanted in 1971 and over the next 15 years 65 plantings of F1 and F2 hybrids were established throughout eastern United States and southeastern Canada. South Korea became interested in the hybrid in the late 1960's and with scions from the Lebanon orchard started their own program. Through the early 1980's millions of hybrids were used to reforest denuded hills in that country. In the 1980's France obtained hybrid seed and acheived spectacular growth rates. They later visited some Station plantings in Maryland and took back scions from the orchard to start a program in France. In this country Westvaco now produces and plants millions of hybrid pitch x loblolly every year and in 1993 International Paper Company initiated a program for their northern lands. This is one of the most successful research programs initiated by the Station.

    In 1965 the project at the Lebanon Experimental Forest was abolished. The people and programs were reassigned to other research projects. In the mid-1970's the hybrid program was assigned to the Genetics Project at Durham, New Hampshire and Dr. Little remained active in all phases of the work at the Experimental Forest until his retirement in 1979. Several technicians assisted with the hybrid program until the last hybrid seed was produced in the orchard in 1985.


    While the Station continues to maintain the pine breeding orchard at the headquarters site and monitors several plantings of hybrid pines on the surrounding Lebanon State Forest, the bulk of the research initated since 1985 has been by staff and graduate students at the Pinelands Field Research Station.

    One of the problems receiving considerable attention is biodiversity of this unique and fragile area. Researchers are looking at the effects of fragmentation and human induced changes in hydrology of the Pinelands Biosphere Reserve wetlands ecosystem with emphasis on the Atlantic white cedar swamps.

    Another major effort involving several scientists has been the effects of acid deposition on the New Jersey Pine Barrens.

    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 East Coast.


    The Silas Little Experimental Forest is located in the town of New Lisbon, New Jersey.


    Applegate, J.E., S. Little, P.E. Marucci. 1979. Plant and animal products of the Pine Barrens. Proc . Pine Barrens Ecosystem and Landscapes. New Jersey Academy Sci., Academic Press. New York.

    Fenton, R.H. 1964. Production and distribution of sweetgum seed in 1962 by four New Jersey stands. Res. Note NE-18. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 6p.

    Garrett, P.W. 1981. The Northeast pitch x loblolly hybrid program. In: Reserch Needs in Tree Breeding. Proc. 15th North American Quant. Forestry Genetics Group Workshop. Coeur d'Alene, Idaho. 71-79.

    Garrett, P.W., I.F. Trew. 1986. Resistance of pitch x loblolly pine hybrids to fusiform rust (Cronartium quercum f. sp. fusiforme). Plant Disease 70(6): 564-565.

    Kuser, J.E., D.R. Knezick, P.W. Garrett. 1979. Pitch x loblolly pine hybrids after 10 years in southern New Jersey. Northern Journal of Applied Forestry. Vol 4(4): 207-209.

    Little, S. 1945. Influence of fuel types on fire danger. Journal of Forestry 43: 744-749.

    Little, S., E.B. Moore. 1945. Controlled burning in south Jersey's oak-pine stands. Journal of Forestry 43: 499-506.

    Little, S., J.P. Allen, E.B. Moore. 1948. Controlled burning as a dual-purpose tool of forest management in New Jersey's pine region. Journal of Forestry 46: 810-819.

    Little, S. 1950. Ecology and silviculture of white cedar and associated hardwoods in southern New Jersey. Yale University, School of Forestry Bulletin 56. 103 pp.

    Little, S. 1959. Silvical characteristics of Atlantic white-cedar (Chamaecyparis thyoides). Sta. Pap. 118. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 16 p.

    Little, S. 1978. Ecology and silviculture of Pine Barrens forests. Proc. 1st. Research Conf. New Jersey Pine Barrens. Atlantic City, NJ. May 22-23. 105-118.


    Project Leader
    Ecology and Management of Northern Forests
    USDA Forest Service, Northern Research Station
    Louis C Wyman Forest Sciences Laboratory
    271 Mast Rd.
    Durham, NH 03824-0640
    Tel: (603) 868-7632
    Fax: (603) 868-7604