Conserve and Enhance Timber Productivity and Wood Quality

The demand for wood products here in the United States is climbing at twice the rate of population growth. NRS scientists work in many scientific disciplines to develop methods to conserve and enhance forest wood resources. Some work to grow timber trees effectively and efficiently, others to ensure adequate regeneration of seedlings and effective yet non-damaging methods of timber harvest. Additional work focuses on processing and using timber products most efficiently and developing new markets for previously unused forest wood products. NRS research foresters work to find ways that will make significantly more wood available on public and private lands. They work to develop methods to 1) improve genetic material for plantation forestry, 2) improve cost-effectiveness of silvicultural systems, 3) develop more-efficient, environmentally friendly harvesting systems, and 4) find socially acceptable ways to implement high-yield forestry where appropriate. As part of their efforts, many of these groups are providing computer programs and training to assist land managers meet their goals.

Research Studies

Reintroduction of Canker Resistant Butternut
Butternut is a medium-sized tree native to the eastern U.S. that produces a large, tasty nut; unfortunately butternut is threatened by an exotic fungal disease called butternut canker. Through collaboration with local and regional public and private landowners we have identified and propagated over one-hundred butternuts that appear to have improved resistance to butternut canker disease, and we are preparing to characterize their resistance in replicated trials.

Clonal Production of Elite Black Cherry
Black cherry is the only native hardwood species of the genus Prunus that is of high commercial value for timber and sawlog production. In vitro (tissue culture) propagation methods could be the most cost effective way to produce clones of selected, mature, elite black cherry genotypes or genetically improved genotypes.

Breeding and Selecting Poplar for Biofuels, Bioenergy, and Bioproducts
Hybridization of poplars occurs naturally among certain taxonomic sections, as well as from planned breeding efforts. Given that most of the variability of poplars is at the species level, both intra- and inter-specific hybridization have been vital tools for producing progeny that outperform either or both parents for biologically and economically important traits. It is important to refine breeding, testing, and selection protocols so that new, superior poplar genotypes can replace their underperforming counterparts.

Enhanced Adaptation to Climate Change of Conifer Species and Provenances in Northern Forest Ecosystems
Over 12 million trees were distributed from Wisconsin state forest nurseries in 2007. The success of such regeneration programs depends upon the development of adaptation strategies for enhanced ecosystem sustainability under changing climates. There is a need to identify species and seed sources with enhanced adaptation to climate change pressures to ensure biologically and economically sustainable reforestation, afforestation, and gene conservation.

Biofuels, Bioenergy, and Bioproducts from Short Rotation Woody Crops
We are testing the genetics, physiology, and silviculture of poplar crops. Specific areas of interest include quantitative genetic analyses of biomass, rooting, and other important traits from hundreds of genotypes grown throughout the North Central United States, as well as analyses of tree growth regulating mechanisms in the face of varying environments and changing climate. Our silviculture research includes a range of studies from vegetation management to yield trials.

Designing Pest-Resistant Forest Landscapes: The Importance of Spatial Pattern
Defoliating insects damage millions of acres of forested land annually in the United States.  The balance of evidence suggests forest insect outbreaks today are more damaging than ever because of changes in forest composition and structure induced by fire suppression and post-harvest proliferation of tree species intolerant to herbivory.  Our central hypothesis is that landscape connectivity of acceptable host types increases defoliator population connectivity, altering the dynamics and spatial structure of defoliator populations, and thus increasing forest susceptibility to insect pest damage.   

Long-term Silvicultural Studies
The Northern Research Station has a long history of traditional silvicultural research, often associated with our 22 experimental forests. Our early silvicultural research (1920s to 1980s) focused on regeneration, thinning, cutting methods, and growth and yield. These studies provided the scientific basis for many guides, stocking charts, and management tools that are still used by resource managers today. Over a half century after their establishment, we are still maintaining and monitoring many of these studies for additional data. Experimental Forests in the: Midwest, Northeast

Best management practices
Forests are managed for a wide range of desired outcomes including fiber production, water quality, wildlife habitat and esthetic appeal. NRS scientists are active in developing “best management practices” (aka BMPs) for various specific forest types and location. BMPs are guidelines designed to meet the desired outcomes while protecting and maintaining forest ecosystems for future generations

Forest renewal
The key to sustaining forests is successfully renewing all their elements after disturbance, across landscapes, and through time. NRS scientists are working to strengthen our understanding of the relationships among certain elements of forest communities in stands and forests of different ages, species compositions, and disturbance history and patterns. Sometimes BMPs and traditional silviculture run up against new problems.

Fire and non-native invasive plants
Recently, populations of non-native plants have been invading northeastern and midwestern forests. In 2001, NRS scientists in the Northeast began a study to evaluate two key topics regarding fire and invasive species: how cutting and prescribed fire treatments (timed to the phenology of carbohydrate depletion and recovery) affect the survival of several woody invasive species; and how treatments alter fuel beds and affect fire behavior in invaded and uninvaded landscapes. Other NRS scientists have found that the invasive non-native tree ailanthus (aka tree-of-heaven) has the ability to invade openings in West Virginia forests caused by fire or timber harvest) and prevent regeneration of oaks and other associated hardwoods.

Deer exclusion is necessary for forest regeneration
Overpopulations of deer are serious threats to forest regeneration. The forestry experience in the northern tier of Pennsylvania is that excluding deer by fencing them out is often necessary to ensure forest regrowth from seeding or planting. NRS scientists have scientifically determined the optimum limit for deer populations.

Regenerating oaks in Missouri's bottomlands
Young oaks growing in river bottomlands face serious competition from the lush growth of native and non-native plants. Because oak seedlings grow slowly, they are often shaded out by Johnson grass, reed canary grass, giant ragweed, mare’s-tail, cottonwood, willow and other fast-growing species that are better adapted to colonizing bare, open bottomland fields.

The effect of growing season treatments on invasive woody plant species
During 2001, we began a study to evaluate two key topics regarding fire and invasive species in the Northeast: how cutting and prescribed fire treatments, timed to the phenology of carbohydrate depletion and recovery, affect the survival of several woody invasive species; and how treatments alter fuel beds and affect fire behavior in invaded and uninvaded landscapes.