Our research teams are strategically located to conduct research in physiographic subregions of the upland hardwood ecosystems, including Asheville, NC, Huntsville, AL, Knoxville, TN, Clemson, SC, and Hot Springs, AR.

The forests of the southern portion of the upland hardwood region occupy 143 million acres in the southeastern and south-central U.S. They are among the most diverse temperate forests in the world, harboring a high level of endemic and threatened and endangered plant and animal species.

Photo Credit

Christine Martens, USDA Forest Service

Forestry Technician, Molly Suminski, shows us a white oak (Quercus alba) acorn while collecting them for planting in a nursery.

Oaks (Quercus spp.) are keystone species in these forests, providing wildlife habitat and food and contributing to food webs, carbon sequestration, water quantity and quality, and local, regional, and global economies. Non-industrial private landowners own the majority of forests in the region. Timber management investment organizations, state and federal agencies including seven national forests, and NGOs own a small but significant portion of southern forests.

These forests face unprecedented forest health concerns, climate change, and urban development. In many parts of the region, oaks and hickories are being replaced by species that do well in moister conditions due to changes in disturbance regimes such as fire.

In addition, nonnative insects and pathogens have resulted in the loss of keystone species such as American chestnut (Castanea dentata) and declines in other trees like hemlock (Tsuga canadensis). Climate change and other factors threaten the persistence of high-elevation red spruce (Picea rubens)-Frasier fir (Abies fraseri) forests. Droughts have led to millions of acres of oak decline.

Maintaining diverse wildlife communities requires management for forest structures and features that meet requirements of bats, birds, reptiles, amphibians, pollinating insects, and other species associated with different forest age classes and conditions. We conduct long-term, broad-scale experiments and observational studies that address a variety of questions and model these disturbances across space and time to address three Problem Areas in the Unit charter:

• Improve management of southern upland hardwood forests for an array of ecosystem services and predict the effects of disturbances to inform  restoration and management goals.
• Improve understanding of wildlife responses to silvicultural treatments and natural disturbances that affect vegetation composition, habitat structure, and food resources as well as the impacts of diseases, and develop and improve techniques for wildlife inventory and monitoring.
• Improve species and ecosystem restoration and genetic conservation of upland species.
• Develop and test silviculture methods for restoring extirpated species, such as American chestnut, or those facing potential extirpation, such as red spruce.
• Increase knowledge of genetically imperiled species to improve the regeneration of upland species undergoing restoration efforts.

The Unit’s history began at the Biltmore Estate in the late 1910s, when Earl Frothingham collected data from experimental forest plantings established by estate forester Dr. Carl Schenck. Those data and continuing observations would be the source of some of the first research results from the Appalachian Forest Experimental Station, established in 1921 by Frothingham, also the first project leader of field research at Bent Creek Experimental Forest (BCEF), which was established in 1925.

Photo Credit

USDA Forest Service

Horse-drawn logging wagons in Bent Creek Experimental Forest in the early 1900s

Early studies at BCEF investigated silvicultural methods to rehabilitate existing, heavily cutover timber stands that were typical of woodlots resulting from 100 years of pioneer subsistence farming; Research also included the replacement by oaks of blight-killed chestnut, the effects of woods burning on hardwood timber stands, and shortleaf pine mortality from southern pine beetles.

In the early 1950s, research focused on planting white pines to increase the productivity of low-quality mountain lands of landowners and the Appalachian national forests. A need for oak regeneration research became evident in the late 1960s, when it was noted that northern red oak was not regenerating after timber harvests in cove stands on national forests.

The 1990s were the beginning of major changes in the scope of silviculture research at BCEF, following the agency’s ecosystem management policy that broadened the focus of management goals. Wildlife management had long been a component of silviculture research at BCEF, but the emphasis was on game species alone. Research studies were expanded to include non-game species such as birds, herpetofauna, and small mammals, along with continued focus on the oak regeneration problem.

In the 2000s, research began on the restoration of prescribed fire in forests of the Cumberland Plateau, American chestnut and oak regeneration, and landscape ecology.

Silviculture and Forest Ecology Research

Photo Credit

Christine Martens, USDA Forest Service

Forest Ecologist, Stacy Clark, and Forestry Technician, Jarrod Sanchez, sorting white oak seedlings for planting experiments.

Current silviculture and forest ecology research includes a wide range of topics on forests in the central hardwood region including the southern Appalachian Mountains and the Cumberland Plateau. A sample of current research includes:

Oak silviculture

Oak-hickory forests are experiencing a lack of large competitive oak regeneration. Current research aims to find ways of successfully regenerating oaks into the overstory. Current projects include the Appalachian Femelschlag, artificial regeneration (planting) projects, prescribed fire studies, oak decline research, and studies on the physiological responses of trees to disturbance.

Mixed hardwood-pine silviculture

Hardwoods are commonly found in mixed stands with pines, and we research the response of mixed hardwood-pine forests to management, including harvesting, herbicide, and prescribed fire.

American chestnut planting and silviculture

The American chestnut was ecologically extirpated by the chestnut blight. Our Unit conducts research on hybrid American-Chinese chestnuts, including their silviculture, resistance to blight, and ability to compete in natural conditions.

Old growth and mature forest

Scientists in our unit are collaborating with foresters across the nation to describe, define, identify, and quantify old growth and mature forests and their ecology.

Landscape ecology and remote sensing

We study how disturbances and climate change affect forest structure, species composition, and carbon sequestration in eastern forests at broad, landscape scales and with the use of remote sensing technology. Research projects include projecting changes in the distribution of spruce-fir forests, identifying possible climatic refugia, testing models of mature and old-growth resilience, and modeling how climate change, forest management, and other disturbances may affect upland forests over the next 20-100 years.

Forest disturbances

Natural disturbances include wildfire, hurricanes, tornadoes, and insects and diseases. Artificial disturbances include prescribed fire and tree harvesting. Artificial disturbances often aim to mimic natural or historic disturbances to simulate conditions favorable for regenerating forest types, like oak-hickory forests.

Wildlife Research

Our wildlife research focuses on the effects of forest management on wildlife species. Current projects include:

Photo Credit

USDA Forest Service photo by Christine Martens.

A tricolored bat that has been banded. Tricolored bats weigh less than a quarter of an ounce, but when they're not hibernating they eat up to half their body weight in insects every night. Tricolored bats appear to be changing their behavior in ways that are helping them survive white-nose syndrome. 

• Effects of prescribed fire and wildfire on reptile, amphibian, and breeding bird communities.
• Production of forest food resources, such as native fleshy fruit and hard mast, in relation to forest types and silvicultural disturbances.
• Long-term monitoring of amphibian populations in longleaf pine-wiregrass sandhills in relation to forest health and climate change.
• Ecology and conservation of threatened, endangered, and sensitive bats.
• Effects of forest management and other disturbances on bat populations.
• Response of southeastern bats to white-nose syndrome.
• Development and refinement of monitoring methods for bats, particularly the North American Bat Monitoring Program (NABat).