The New York Natural Heritage Program considers Appalachian oak-hickory forests "matrix forests." Matrix forests blanket large regions of the state and include patches of other natural communities. If the High Allegheny Plateau along the New York-Pennsylvania line were thought of as a giant chocolate chip cookie, then Appalachian oak-hickory forests would be the cookie dough and the chips would be the other embedded communities such as lakes, bogs, and swamps.
There are several hundred occurrences statewide. Some documented occurrences have good viability and many are protected on public land or private conservation land. This community has statewide distribution and includes several very large, high quality examples. The current trend of this community is probably stable for occurrences on public land, or declining slightly elsewhere due to moderate threats related to development pressure.
The number and acreage of Appalachian oak-hickory forests in New York has probably declined moderately in recent decades as a result of logging, agriculture, and other development.
The number and acreage of Appalachian oak-hickory forests in New York has probably declined substantially from historical numbers likely correlated with past logging, agriculture, and other development.
Threats to forests in general include changes in land use (e.g., clearing for development), forest fragmentation (e.g., roads), and invasive species (e.g., insects, diseases, and plants). Other threats may include over-browsing by deer, fire suppression, and air pollution (e.g., ozone and acidic deposition). When occurring as expansive forests, the largest threat to the integrity of Appalachian oak-hickory forests are activities that fragment the forest into smaller pieces. These activities, such as road building and other development, restrict the movement of species and seeds throughout the entire forest, an effect that often results in loss of those species that require larger blocks of habitat (e.g., black bear, bobcat, certain bird species). Additionally, fragmented forests provide decreased benefits to neighboring societies from services these societies often substantially depend on (e.g., clean water, mitigation of floods and droughts, pollination in agricultural fields, and pest control) (Daily et al. 1997). Appalachian oak-hickory forests are threatened by development (e.g., residential, agricultural, communication antennas), either directly within the community or in the surrounding landscape. Other threats include habitat alteration (e.g., roads, utility ROWs, excessive logging, mining, deer over-browsing), and recreational overuse (e.g., ATVs, hiking trails, campgounds, ski slopes). A few Appalachian oak-hickory forests are threatened by invasive species, such as buckthorn (Rhamnus cathartica), bluegrass (Poa compressa), barberry (Berberis thunbergii), shrubby honeysuckle (Lonicera morrowii), tree-of-heaven (Ailanthus altissima), and multiflora rose (Rosa multiflora). Intentionally planted pine species (e.g., Pinus resinosa, P. strobus) may become established and be a threat to a few examples. Appalachian oak-hickory forests may be threatened by the non-native gypsy moth (Lymantria dispar) which is one of North America's most devastating forest pests. The gypsy moth is known to feed on the foliage of hundreds of species of plants in North America but its most common hosts are oaks and aspen. Gypsy moth populations are typically eruptive in North America; in any forest stand densities may fluctuate from near 1 egg mass per ha to over 1,000 per ha. When densities reach very high levels, trees may become completely defoliated. Several successive years of defoliation, along with contributions by other biotic and abiotic stress factors, may ultimately result in tree mortality (McManus et al. 1980, Liebhold 2003).
Management should focus on activities that help maintain regeneration of the species associated with this community. Deer have been shown to have negative effects on forest understories (Miller et al. 1992, Augustine and French 1998, Knight 2003) and management efforts should strive to ensure that regenerating trees and shrubs are not so heavily browsed that they cannot replace overstory trees. Avoid cutting old growth examples and encourage selective logging areas that are under active forestry.
Strive to minimize fragmentation of large forest blocks by focusing development on forest edges, minimizing the width of roads and road corridors extending into forests, and designing cluster developments that minimize the spatial extent of the development. Development projects with the least impact on large forests and all the plants and animals living within these forests are those developments built on brownfields or other previously developed land. These projects have the added benefit of matching sustainable development practices (for example, see: The President's Council on Sustainable Development 1999 final report, US Green Building Council's Leadership in Energy and Environmental Design certification process at http://www.usgbc.org/).
Inventory any remaining large and/or old-growth examples across the state. Continue searching for large sites in excellent to good condition (A- to AB-ranked).
Regularly assess the presence and degree of impact that gypsy moths have on this community. Research the composition of Appalachian oak-hickory forests statewide in order to characterize variations. Collect sufficient plot data to support the recognition of several distinct Appalachian oak-hickory forest types based on composition and by ecoregion.
This community is currently known from the lower Hudson Valley within the Hudson Highlands, the Hudson Limestone Valley, and the Taconic Foothills. Appalachian oak-hickory forests are also known from the Catskill Mountains, the St. Lawrence and southern Lake Champlain Valleys, the Lake George Valley, the Upper Delaware River Valley, and the western Finger Lakes Region.
The range as a broadly-defined floristic community may be most of the Appalachian Mountains from Maine, south to Alabama and Georgia. Range of occurrences with closest floristic affinities to New York may extend north to Maine, south toTennessee and west to Ohio and Kentucky.
A hardwood forest that occurs on well-drained sites, usually on ridgetops, upper slopes, or south- and west-facing slopes. The soils are usually loams or sandy loams. This is a broadly defined forest community with several variants. The dominant trees include one or more species of oak.
This forest invariably has a mixture of tree oaks (red, white, black) and hickories (pignut, shagbark, sweet pignut). Also, maple-leaf viburnum is commonly found in the understory.
Known examples of this community have been found at elevations between 200 feet and 2,280 feet.
Early spring is a good time to catch many of the understory trees and shrubs in bloom. Flowering dogwood, shadbush, choke cherry, and maple-leaf viburnum all provide visual sprays of color in the spring.
This New York natural community encompasses all or part of the concept of the following International Vegetation Classification (IVC) natural community associations. These are often described at finer resolution than New York's natural communities. The IVC is developed and maintained by NatureServe.
This New York natural community falls into the following ecological system(s). Ecological systems are often described at a coarser resolution than New York's natural communities and tend to represent clusters of associations found in similar environments. The ecological systems project is developed and maintained by NatureServe.
Acer saccharum (sugar maple)
Carya glabra (pignut hickory)
Fraxinus americana (white ash)
Ostrya virginiana (hop hornbeam, ironwood)
Quercus alba (white oak)
Quercus montana (chestnut oak)
Quercus rubra (northern red oak)
Cornus florida (flowering dogwood)
Hamamelis virginiana (witch-hazel)
Vaccinium pallidum (hillside blueberry)
Viburnum acerifolium (maple-leaved viburnum)
Aralia nudicaulis (wild sarsaparilla)
Carex pensylvanica (Pennsylvania sedge)
Hepatica americana (round-lobed hepatica)
This figure helps visualize the structure and "look" or "feel" of a typical Appalachian Oak-Hickory Forest. Each bar represents the amount of "coverage" for all the species growing at that height. Because layers overlap (shrubs may grow under trees, for example), the shaded regions can add up to more than 100%.
Augustine, A.J. and L.E. French. 1998. Effects of white-tailed deer on populations of an understory forb in fragmented deciduous forests. Conservation Biology 12:995-1004.
Daily, G.C., S. Alexander, P.R. Ehrlich, L. Goulder, J. Lubchenco, P. Matson, H.A. Mooney, S. Postel, S.H. Schneider, D. Tilman, and G.M. Woodwell. 1997. Ecosystem Services: benefits supplied to human societies by natural ecosystems. Issues In Ecology 2:1-16.
Edinger, G. J., D. J. Evans, S. Gebauer, T. G. Howard, D. M. Hunt, and A. M. Olivero (editors). 2014. Ecological Communities of New York State. Second Edition. A revised and expanded edition of Carol Reschke’s Ecological Communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation, Albany, NY. http://www.dec.ny.gov/docs/wildlife_pdf/ecocomm2014.pdf
Edinger, Gregory J., D.J. Evans, Shane Gebauer, Timothy G. Howard, David M. Hunt, and Adele M. Olivero (editors). 2002. Ecological Communities of New York State. Second Edition. A revised and expanded edition of Carol Reschke's Ecological Communities of New York State. (Draft for review). New York Natural Heritage Program, New York State Department of Environmental Conservation. Albany, NY. 136 pp.
Hagan, J.M. and A.A. Whitman. 2004. Late-successional Forest:A disappearing age class and implications for biodiversity. Manomet Center for Conservation Sciences. 4 pp.
Knight, T.M. 2003. Effects of herbivory and its timing across populations of Trillium grandiflorum (Liliaceae). American Journal of Botany 90:1207-1214.
Liebold, S. 2003. Gypsy Moth in North America. U.S. Department of Agriculture, Forest Service, Northeastern Research Station, Morgantown, WV. http://www.fs.fed.us/ne/morgantown/4557/gmoth Accessed March 2, 2005.
McIntosh, R.P. 1972. Forests of the Catskill Mountains, New York. Ecol. Monogr. 42:143-161.
McManus, M, N. Schneebergerm R. Reardon, and G. Mason. 1980. Gypsy Moth. Forest Insect and Disease Leaflet 162. U.S. Department of Agriculture, Forest Service, Washington, D.C.
Miller, S.G., S.P. Bratton, and J. Hadidian. 1992. Impacts of white-tailed deer on endangered and threatened vascular plants. Natural Areas Journal 12:67-74.
New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.
Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.
Ross, P. 1958. Microclimatic and vegetational studies in a cold-wet deciduous forest. Black Rock Forest Papers No. 24, Harvard Black Rock Forest, Cornwall-on-the-Hudson, New York.
The President's Council on Sustainable Development. 1999. Towards a Sustainable America: Advancing Prosperity, Opportunity, and a Healthy environment for the 21st Century. Washington, DC. 97 pp. plus appendices.
Information for this guide was last updated on: March 2, 2017
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Appalachian oak-hickory forest. Available from: https://guides.nynhp.org/appalachian-oak-hickory-forest/. Accessed January 18, 2019.