Efficacy of using uneven-aged management to regenerate mixed-hardwood forest stands

Research Issue

The forest systems of the southern Appalachian Highlands are diverse in their ecology, and their ability to provide the resources and services demanded by society including water, timber and biomass, recreation, wildlife habitat, aesthetics, and landscape diversity. Minor changes in topography greatly affect site productivity, species composition, competitive interactions, and response to disturbance. Our limited understanding of forest dynamics and ecological processes throughout stand development and across this complex landscape greatly inhibits land managers’ ability to predict the response of vegetation to both planned silvicultural treatments and unplanned natural disturbance events. There is a need to improve our knowledge of the establishment and sustainability of forested systems under the influence of natural and silvicultural disturbances as well as under varying climatic scenarios. Silviculture is used by resource managers and forest planners to balance multiple-use with sustainability. Our efforts to predict and manage the dynamics of southern Appalachian forests under disturbances is directly tied to our ability to understand the differential responses of southern Appalachian tree species to both natural and anthropogenic (i.e., silvicultural) disturbances. Quantification of the response of vegetation (both arborescent and herbaceous vegetation) to disturbance will better enable natural resource practitioner to better predict changes in forest structure, composition, and habitat quality and to develop methods to meet management and restoration goals. click for more...

Our research

This study was conducted on approximately 40 ha of the Bent Creek Experimental Forest hereafter termed ‘The Farm Woodlot’ in Asheville, North Carolina (35.5°N, 82.6°W). The Bent Creek Experimental Forest lies within the Blue Ridge Physiographic Province of the southern Appalachian Mountains. The Farm Woodlot is divided into seven separate stands that range in size from 2.4 to 14.4 ha. Species composition of the study area is typical of upland hardwood forests of the southern Appalachian Mountains. The predominant overstory species include mid-tolerant oak (Quercus rubra, Q. velutina, Q. coccinea, Q. alba, Q. prinus) and hickory (Carya spp.) species and shade-intolerant yellow-poplar (Liriodendron tulipifera). The lower canopy layers are dominated by shade-tolerant and often non-merchantable species, including sourwood (Oxydendrum arboreum), black gum (Nyssa sylvatica), flowering dogwood (Cornus florida), and red maple (Acer rubrum). click for more...

Expected Outcomes

Results from this study suggest the application of single-tree selection via the BDq method of regulating stocking with the current assignment of BDq parameters is unsustainable in mixed-hardwood forests of the southern Appalachians where species composition is primarily comprise of shade-intolerant and mid-tolerant species. Consequently, it is not a recommended method f regeneration in the forest types that lack a shade-tolerant canopy tree species, such as sugar maple (Acer saccharum). Although this study can only attest to the efficacy of using the BDq approach to single-tree selection in productive mixed-hardwood forests, other methods, such as management of growing space among cohorts may be more appropriate in forest types where intolerant and mid-tolerant species are the species of management concern.

Research Results

Keyser, T.L., and D.L. Loftis. Long-term effects of single-tree selection on structure and composition in upland mixed-hardwood forests of the southern Appalachians Mountains. In review.

Lewis, J.R., J.W. Groninger, and D.L. Loftis. 2006. Regeneration response to midstory control following long-term single tree selection management of southern Appalachian hardwoods. USDA For. Ser. Gen. Tech. Rep. SRS-92.

Della-Bianca, L. and Beck, D.E. Beck. 1985. Selection management in southern Appalachian hardwoods. South. J. Appl. For. 9: 191-197.

Research Principal Investigators

Dr. Tara L. Keyser, Research Forester, Southern Research Station RWU-4157, Asheville, North Carolina

Dr. David. L. Loftis, Research Forester (emeritus), Southern Research Station RWU-4157, Asheville, North Carolina

Research Partners

Pisgah National Forest, Pisgah Ranger District