Speaker Abstracts

    Prescribed fire, oak regeneration, and future forest flammability


    Heather D. Alexander, Mary Arthur, Marcus Lashley, Courtney Siegert, Brian Izbicki, and Emily Babl


    Assistant Professor (HAD), Assistant Professor (CS), and Graduate Research Assistants (BI and EB), Department of Forestry, Forest and Wildlife Research Center, Mississippi State University; Professor (MA), Department of Forestry and Natural Resources, University of Kentucky; Assistant Professor (ML), Department of Wildlife, Fisheries, and Aquaculture, Forest and Wildlife Research Center, Mississippi State University


    Prescribed fire is a common management tool applied to upland oak forests of the Central Hardwood and southern Appalachian regions to promote oak regeneration. Increased use of prescribed fire is largely driven by paleoecological and dendrochonological evidence showing fire and upland oaks co-occurred across the landscape, morphological and physiological traits suggesting oaks are fire-adapted, and increased dominance of shade-tolerant “mesophytes” following fire suppression. To assess whether fire restoration to these forests could improve oak regeneration, we implemented several studies across the region to evaluate the (1) impacts of single vs. multiple dormant-season burns on understory light conditions and tree seedling growth and survival; (2) interacting role of fire season and mammalian herbivory on re-sprout success of top-killed trees; and (3) variability in tree bark, canopy, and leaf litter traits that could influence future forest flammability through changes in fuel characteristics. Thus far, our findings suggest that (1) multiple dormant-season burns marginally improve oak regeneration; (2) growing-season burns may enhance oak regeneration by increasing herbivory on mesophytes; and (3) mesophytes may suppress future forest flammability by reducing fuel loads and increasing fuel moisture.

    Impacts of gypsy moth and other native spring defoliators on the oak resource in the context of ageing cohorts, excessive volume, and poor regeneration rates.


    Chris Asaro, Forest Health Monitoring Program Manager, Southern Region, USDA Forest Service


    There is some concern for the future of oak forests due to increasing rates of decline and loss among maturing cohorts of oak-dominant canopies that are not being sufficiently replaced by oak

    regeneration. Among a variety of spring defoliators, the gypsy moth (Lymantria dispar L.) and fall cankerworm (Alsophila pometaria Harris) have been major contributors to oak decline in Virginia due to repeated outbreaks spanning many acres and successive years. Many spring defoliators exhibit eruptive population dynamics and spring defoliation causes more harm to host trees than defoliation that occurs later in the growing season. Annual defoliation data from a variety of spring defoliators were collected and summarized from pest survey records by the Virginia Department of Forestry spanning 1953-2014. While gypsy moth was the most damaging agent during this time span, fall cankerworm has been more damaging from 2005-2014. Fall cankerworm is the most common native defoliator in Virginia, with outbreaks occurring approximately every five years. Other native spring defoliators that prefer oaks have been in outbreak status, albeit less frequently. Overall, defoliator outbreaks may exacerbate oak decline where they occur, resulting in more rapid loss of oak-dominant canopies and a transition to alternate forest types over time.

    Considerations for the utilization of oak


    Brian Bond, Professor, Department of Sustainable Biomaterials, Virginia Tech


    The commercial groupings of red and white oak make up the majority of timber in the central hardwood region. Getting the highest value during utilization is important for the management of forests, forest landowners and the regional economy; therefore, understanding the limitations of the raw material; and proper handling and processing is critical. This presentation will focus on a description of material limitations, such as: mineral stain, bacterial infection, and why differences in price exist for the “same” material; utilization considerations, such as, reducing log yard degrade, phytosanitation requirements for log shipments overseas, longer drying times, drying methods used, and difficulty with checking will also be discussed. 

    Fitting prescribed fire into the oak regeneration process


    Patrick H. Brose, Research Forester, Northern Research Station, USDA Forest Service


    Regenerating a mixed-oak forest is typically described as a process that can take 10 to 25 years depending on numerous intrinsic and extrinsic factors.  Prescribed fire can help expedite this journey and increase oak stocking at the end of the process if the burning is done at the correct time and in the correct manner.  This talk will review the oak regeneration process and show where fire fits into this process and how to do it.  Also, the talk will cover commonly made mistakes that can result in increased regeneration difficulties or regeneration failures.  Finally, a couple of case studies of successful fire use will be presented.     

    Forest management for Golden-winged and Cerulean Warblers- lessons learned from forest management experiments


    David A. Buehler, Douglas Raybuck, Justin Lehman, Than Boves, and Jeffrey Larkin


    Professor (DAB), PhD Student (DR), and Master’s Student (JL), Department of Forestry, Wildlife, and Fisheries, The University of Tennessee; Assistant Professor (TB), Department of Biological Sciences, Arkansas State University; Professor (JL), Department of Biology and American Bird Conservancy, Indiana University of Pennsylvania


    Golden-winged Warbler (Vermivora chrysoptera) and Cerulean Warbler (Setophaga cerulea) are two of the most rapidly declining forest songbird species that occur in oak-dominated forests in eastern North America.  Both species occupy large forested landscapes but generally occur at opposite ends of the successional spectrum with Golden-winged Warbler preferring young forests and Cerulean Warblers preferring mature forests.  We conducted two forest management experiments on these focal species in the Cumberland Mountains, Tennessee as the foundation for development of forest management guidelines for creating and restoring breeding habitat.  Based on monitoring changes in forest stand structure post-harvest, along with changes in warbler abundance and reproduction, we learned some important lessons about how forest management can be used to manage these species in isolation and where they are sympatric.   

     Overview of oak markets and marketing


    Matt Bumgardner, Research Forest Products Technologist, Northern Research Station, USDA Forest Service


    The height of oak popularity in the U.S. marketplace came in the early 1990s as the furniture and cabinet industries made use of large quantities oak in their designs, especially red oak.  This familiarity has led to a consumer awareness for oak that surpasses other commercial hardwood species.  More recently, however, oak’s position in many U.S. fashion-based markets has waned (flooring being an exception) and oak exports have surged.  Exports of U.S. red oak alone surpassed 440 million board feet in 2016, which was a record for any species exported from the United States.  Over 70 percent of current U.S. red oak exports go to China while export markets for U.S. white oak are more diverse.  Industrial markets such as pallets and railway ties also have been critical for oak utilization, especially after the Great Recession and associated housing market decline.  Since 2012, white oak stumpage and lumber prices have increased faster than other hardwoods, reflective in part of increasing demand.  This presentation will provide an overview of these changes in oak markets and discuss some of the implications for oak management in the future.

     Identifying and addressing vulnerabilities of oak ecosystems in the northeast and midwest


    Patricia Butler, Climate Change Outreach Specialist, Northern Institute of Applied Climate Science


    We developed eight ecosystem vulnerability assessments to help inform potential adaptation actions in response to climate change. Our approach combines multiple quantitative models and expert elicitation from scientists and land managers. In each assessment area, these local experts assessed vulnerability of forest ecosystems to climate change over the next century. The climate change impacts most frequently identified were changes in fire regime, soil moisture, pest and disease outbreaks, and nonnative invasive species. An increase in summer drought conditions was a larger concern in the Midwest regions than along the East Coast. Increases in heavy precipitation events was a greater concern along the East Coast than in the Midwest. Where fire-tolerant oak and hickory species were replaced by maple and beech species, mesophication was listed as a factor reducing adaptive capacity. However, compared to other ecosystems like conifers and northern hardwoods, oak and hickory forests were rated with relatively low vulnerability. Managers have used information from these assessments in projects and planning in both the public and private sector, on individual project areas and through coordinated efforts in large landscapes. For example, state and federal agencies collaboratively developed strategies for oak management in southeast Ohio for public and private forest lands.

     Strong Markets - Stronger Challenges


    Henry Christ, President, Dunaway Timber Company


    "Yes it really is rocket science." A look at the past 30 years and how the wood market has survived even though the economic environment has become more difficult. Today's challenges have changed dramatically over the past three decades.

     The past, present, and future of planting upland oaks


    Stacy L. Clark and Scott E. Schlarbaum


    Research Forester (SLC), Southern Research Station, USDA Forest Service; Professor and Director (SES), Tree Improvement Program, Department of Forestry, Wildlife, and Fisheries, The University of Tennessee


    Oaks (Quercus) have been planted since colonial days in the United States, but efforts have been largely unsuccessful on upland sites intended for reforestation following commercial tree harvesting. Failures can be attributed to poor seedling quality, animal damage, and use of poorly adapted seed sources. From the 1970s to the 1990s, large gains were made in tree improvement programs and nursery technology intended to improve planting success. Despite these advancements, success is limited on sites where light-seeded hardwoods are primary competitors. Research is underway to further refine selection for seedling quality and to examine effects of prescribed burning, top-clipping and competition control treatments. Pedigree selections for desirable nursery traits and field performance can be made, but infrastructure for fine hardwood tree improvement programs has declined steadily nationwide. Progressive success of planting oaks will depend on balancing tree improvement with nursery and silvicultural prescriptions.   

     What Do We Know About Oaks? Keystones of Oak Silviculture


    Wayne Clatterbuck, Professor, Department of Forestry, Wildlife and Fisheries, The University of Tennessee


    The presentation involves past and present research about oak species, what is known and not known, and the opportunities or priorities for future oak research to successfully manage oak environments.

     Silviculture approaches to restoring oak-pine woodlands and savannas


    Daniel C. Dey, Benjamin O. Knapp, Michael C. Stambaugh


    Project Leader and Research Forester (DCD), Northern Research Station, USDA Forest Service;

    Assistant Professor (BOK) and Associate Research Professor (MCS), School of Natural Resources, University of Missouri


    Restoration of oak-pine savannas and woodlands is a primary goal for public agencies and conservation organizations. Although they can be restored with a long-term regimen of prescribed burning, often, prescribed fire alone is not the most efficient way because larger trees are more resistant to fire, and fire can actually exacerbate problems with invasive species.  Usually a combination of fire, timber harvesting or thinning, and vegetation management by herbicide application often produces the desired structure and composition more efficiently while addressing problems with competing or invasive vegetation. Integrating fire within a modified shelterwood approach promotes competitive oak and pine reproduction and is flexible to produce savannas or woodlands. Prescriptions for restoration are guided by knowledge of historical vegetation structure and composition, modern high quality reference sites, physiology and ecology of desired species, initial vegetation conditions, and site quality. Desired future condition of the ground flora is a major driver in designing prescriptions. Ground flora is affected by overstory density, fire regime and grazing. Tools are being developed to help managers define and manage stand structure by identifying the natural range of variation in tree stocking associated with savannas and woodlands at various stages of stand development. Eventually, sustaining these communities requires the replacement of the overstory during periods of no fire.

     Artificial regeneration on the North Cumberland Wildlife Management Area in Tennessee


    Joe Elkins, Wildlife Manager II, North Cumberland Wildlife Management Area, Tennessee Wildlife Resources Agency


    Wildlife managers have long recognized the need to manage the forest to insure suitable components of wildlife habitat. Although forest management is a cost-effective and time-tested method to create, maintain, and improve habitat it does have challenges. One challenge faced by land managers is the lack of oak regeneration and the loss of the oak component in regenerated stands. Artificial oak regeneration is one technique the Tennessee Wildlife Resources Agency is exploring to restore or enrich the oak component of harvested stands. Beginning in 2006, 18 forest stands consisting of 265 acres on upland hardwood sites have been planted post-harvest with various oak species. These plantings have been in cooperation with the USDA Forest Service and the University of Tennessee Tree Improvement Program which have provided technical assistance with seedling production and care. We are now evaluating these plantings as the stands reach an age of reentry in our management schedule.

    Fire history in the yellow pine and mixed pine/hardwood forests of the Southern Appalachian Mountains


    Henri D. Grissino-Mayer, Charles W. Lafon, and Sally P. Horn


    Professors (HDG and SPH), Department of Geography, The University of Tennessee; Professor (CWL), Department of Geography, Texas A&M University


    We have been conducting fire history research using tree-ring and sedimentary charcoal proxy records from southeastern forests since 1993, focusing mainly in the yellow pine and mixed pine hardwood forests of the Appalachian Mountains. Our tree-ring studies have shown that area-wide fires burned about once every 7 years (with a range from 5 to 13 years) from the mid-1700s until the early 1900s. One of the sedimentary charcoal studies that we conducted in soil of Great Smoky Mountains National Park revealed that fire was a recurring phenomenon there for thousands of years. Since about 1930, the exclusion of fire has caused changes in (1) tree density, (2) species composition, and (3) stand structure of southeastern forests. We found that 20th century tree establishment now favors more fire-intolerant tree species, such as red maple, black gum, and eastern hemlock, at the expense of fire-tolerant and fire-adapted species, such as the yellow pines and oaks. Without re-introducing fire as a primary disturbance process, we may likely observe that yellow pines may be lost as a major component of Appalachian pine-oak forests. We caution, however, that forests being managed today are essentially “no-analog” forests, such that efforts to restore them based on traditional management strategies may be ineffective.

    Prescribed fire effects on wildlife in eastern oak ecosystems


    Craig A. Harper, Professor, Department of Forestry, Wildlife, and Fisheries, The University of Tennessee


    Fire is being prescribed and used increasingly in eastern oak ecosystems to promote ecosystem restoration (e.g., oak woodlands and savanna) and enhance habitat for wildlife. Primary effects of burning on wildlife are indirect. Fire alters plant structure and composition, which affects habitat quality. Fire effects vary among wildlife species, and not all species benefit from fire. Direct effects on wildlife (injury/death) are relatively rare and largely associated with timing and intensity. Indirect effects are influenced by light availability. Unless fire intensity is great enough to kill trees, canopy reduction treatment that allows > 20% sunlight to the forest floor is necessary to realize meaningful effects. A fire-return interval of 2 – 7 years, depending on site and objectives, benefits a variety of wildlife species by providing diverse understory structure, increased browse, forage, and soft mast. Effects on vegetation composition from early growing-season fire (Apr-May) has not differed from dormant-season fire. Burning during the late growing season (Aug-Oct) may alter composition more effectively. There is no indication that prescribed fire in eastern oak ecosystems is leading to reduced populations of any wildlife species, including taxa of conservation concern. Fire should be applied on ecologically appropriate sites to achieve objectives related to wildlife and ecosystem restoration.

     Successful artificial regeneration of hardwood species on bottomland sites without post-planting management


    Allan E. Houston, Scott E. Schlarbaum, Alison I. Shimer, Jason L. Hogan, and Arnold M. Saxton  


    Research Professor and Leader (AEH), Forest and Wildlife Management Research, Ames Plantation, The University of Tennessee; Professor and Director (SES), Graduate Research Assistant (AIS), Research Associate (JLH), Tree Improvement Program, Department of Forestry, Wildlife, and Fisheries, The University of Tennessee; Professor (AMS), Department of Animal Science, The University of Tennessee


    Regeneration systems for hardwoods have traditionally relied on advance reproduction originating from sprouts or seed banks. Advance regeneration can be hard to establish and the composition of the mature stand difficult to predict.  Enrichment planting of hardwoods on post-harvest sites has often failed due to poorly developed seedlings that must compete with aggressive natural vegetation and require periodic release treatments, which are difficult and expensive. In this research, pedigreed acorns (half-siblings) were planted in the nursery and grown to their maximum potential size.  The largest seedlings were selected for planting in 1-to-3-acre, group selection openings on bottomland sites. Harvest treatments occurred the fall or winter prior to planting. There was no subsequent release or treatment after planting. Various growth and competition characteristics were evaluated over time.  Ten years after planting, the majority of sites are projected to have successful enrichment, as defined by having at least 36 dominant and codominant planted trees per acre free-to-grow and projected to occupy the mature stand.  To increase future productivity of the best trees per acre, fertilization and release treatments will be applied early-to-mid rotation. In separate hardwood studies, these treatments have been shown to triple growth 10 years post-treatment.


     Effectiveness of herbicide and fire to favor oak regeneration in Ohio shelterwood stands


    Todd Hutchinson and Joanne Rebbeck


    Research Ecologist (TH) and Plant Physiologist (JR), Northern Research Station, USDA Forest Service


    Poor oak regeneration is a major problem in the Appalachian Plateau Region, where shade-tolerant species are typically abundant in the midstory and understory. In intermediate quality mixed-oak stands that received a shelterwood harvest (SWH; 50% basal area removal), we examined tree regeneration in response to four treatments replicated at four study sites:  1) control - no additional treatment, 2) herbicide – midstory stem-injection conducted just prior to SWH, 3) fire – dormant-season prescribed fire conducted 5-7 years after SWH, and 4) herbicide + fire.   Tree regeneration was recorded in year 0 (2005, pre-treatment), year 5 (2010, 4-5 years post SWH), and year 10 (2015, 3-4 years post-burn).  By year 5, the sapling strata (stems >4.5’ tall) was dominated by red maple, yellow-poplar, and other shade-tolerant species.  The herbicide treatment did not significantly improve the relative abundance of oak.  However, larger oak seedlings (>2’ tall) and saplings were present on nearly half of the 552 sampling units (6’ radius plots) by year 5.  The response of the regeneration layer to fire by year 10 will be reported.  We also place our results in the context of the SILVAH system for regenerating oak forests.

     Adapting silviculture for climate change: an approach to promote oak


    Louis R. Iverson, Matthew P. Peters, Stephen Matthews, Anantha Prasad, Todd Hutchinson, and Jarel L. Bartig


    Research Landscape Ecologist (LRI), Ecologist (MPP), Wildlife Landscape Ecologist (SM), and Research Ecologists (AP and TH), Northern Research Station, USDA Forest Service; Forest Silviculturist/Landscape Ecologist (JLB), Wayne National Forest, USDA Forest Service


    Rising temperatures and variable precipitation events leading to droughts and floods will increase in frequency. We show evidence for increasing drought for much of the country between two past periods, 1960-1986 and 1987-2013, and three future periods, 2010-2039, 2040-2069, 2070-2099, using an index which combines both scores of monthly drought intensity and frequency. We then model and map potential changes in suitable habitat for 130 tree species (10x10 km) in the eastern United States. Potential adaptability to changing climate was evaluated by literature assessment of biological and disturbance traits. Overall, trends show many species with shrinking habitat but also several drought tolerant species (especially oaks) with increased habitat. However, current oak regeneration is often poor - hence management assistance is needed to ensure an ongoing, thriving oak component. Long-term research in Ohio has shown that prescribed fire and thinning can provide a successful path for oak regeneration, depending on the moisture regime within the landscape. These data informed models of oak regeneration potential (10x10 m) across a 17-county region in SE Ohio. Silvicultural treatments promoting future increasers (e.g., oak) and finding refugia for decreasers can then be devised as means to adapt to the changing climate.

    Adaptive silvicultural strategies for managing oaks in a changing climate


    John M. Kabrick, Stephen R. Shifley, and Dan C. Dey


    Research Foresters (JMK and SRS) and Project Leader and Research Forester (DCD), Northern Research Station, USDA Forest Service


    The Intergovernmental Panel on Climate Change indicates there may be substantial changes to future climates. Although uncertainty remains about the amount and timing of change in a given region, it is incumbent upon silviculturists to consider strategies for managing oaks under future climate scenarios. Most projected climate scenarios in the eastern U.S. appear favorable for oaks; maps of future suitability indicate that oak-hickory and oak-pine forest types in the eastern U.S. will experience increased suitable habitat. However, the presence of favorable growing conditions does not ensure that oaks will remain abundant. Regardless of the climate projection, the greatest threat to oaks in the future is the absence of management today. Adaptive management strategies include the application of commonly used silvicultural practices such as thinning, prescribed burning, and planting. However, these practices need to be applied strategically to enhance stand resistance or resilience, or to transition a stand to include a better adapted species group. Hence, climate change may require altering details associated with oak silviculture at a given location, but the underlying ecological relationships affecting oaks will remain intact, even though disturbances from fire, drought, insects, and diseases may be amplified or dampened by a future climate.

    Wildlife response to oak ecosystem restoration


    Patrick D. Keyser, Andrew L. Vander Yacht, Chrissy A. Henderson, Emma V. Willcox, Max R. Cox, David A. Buehler, Craig A. Harper, Charles Kwit, and Mike Stambaugh.


    Professor and Director (PDK) and Graduate Research Assistants (ALV and CAH), Center for Native Grasslands Management, Department of Forestry, Wildlife, and Fisheries, The University of Tennessee; Assistant Professors (EVW and CK) and Professors (DAB and CAH), Department of Forestry, Wildlife, and Fisheries, University of Tennessee; Conservationist (MRC), USDA Natural Resources Conservation Service; Associate Research Professor (MS), School of Natural Resources, University of Missouri


    The eastern oak (Quercus) forest ecosystem once included extensive open-canopy and early successional communities (i.e., woodlands and savannahs) as a result of frequent fires. However, altered fire regimes resulted in the almost complete elimination of such communities and substantial degradation of remnants. Consequently, associated wildlife populations also experienced declines. A long-term, field experiment conducted at three sites (NC and TN) has explored responses of breeding birds and forest bats to community restoration treatments including, canopy reduction to woodland (60 sqft residual BA) and savannah (30 sqft residual BA) targets and prescribed fire (March and October). Occupancy and abundance of breeding birds was strongly influenced by key measures of structure with early successional avifauna responding positively to increased herbaceous ground cover and decreased live basal area (LBA); associations with midstory density were weaker and less consistent, perhaps due to ubiquitous woody cover in this strata during the restoration process. Occupancy of most late successional species was not sensitive to disturbances associated with restoration with a few exceptions, notably birds that nested or foraged in leaf litter. However, several late successional species indicated some level of disturbance-dependence with positive responses in abundance to canopy reduction across some range of LBA. Early successional species were al most completely absent from controls leading to reduced species richness in these stands. Red-headed woodpeckers (Melanerpes erythrocephalus) selected for pine snags for nest cavities and had very high nest survival rates. Prairie warblers (Setophaga discolor) selected nest sites with greater herbaceous groundcover although this did not influence nest survival, which was quite low in the breeding season immediately after burning and was comparable to other studies one year post-fire. Forest bat activity was greater in disturbed sites, especially stands reduced to savannah target basal areas, than in controls. Woodland and savannah restoration treatments involving canopy reduction and re-introduction of prescribed fire provide positive benefits to imperiled early successional wildlife in oak forest ecosystems and do not appear to negatively impact most species associated with later seral stages.

    Practical considerations for long-term maintenance of oak woodlands


    Benjamin O. Knapp, Michael C. Stambaugh, and Daniel C. Dey


    Assistant Professor (BOK) and Associate Research Professor (MCS), School of Natural Resources, University of Missouri; Project Leader and Research Forester (DCD), Northern Research Station, USDA Forest Service


    Contemporary oak woodland management practices commonly focus on transitioning closed-canopy forests to the target structure and composition of woodlands. Managing oak woodlands over the long-term requires maintenance of that structure and composition, including a relatively low-density canopy, open vertical structure, and herbaceous ground flora. For most woodland sites in the eastern United States, maintaining open structural conditions and the desired herbaceous vegetation requires repeated, frequent prescribed burning. However, frequent prescribed burning can also damage hardwood trees, reducing the longevity of the canopy while limiting opportunities for canopy replacement through regeneration. We provide empirical examples from recent studies to highlight these points and discuss practical approaches to dealing with this paradox of oak woodland management in the context of traditional silvicultural concepts. These apparent challenges suggest consideration of operational limitations as well as trade-offs concerning management objectives when planning long-term oak woodland management. 

    Manual herbicide application methods for managing vegetation in Appalachian hardwood forests


    Jeff Kochenderfer, Silviculturist, Monongahela National Forest, USDA Forest Service


    Controlling undesirable vegetation is a major component of any silvicultural system involving the management of oaks. It has long been recognized that controlling understory competition before harvest and timely release after harvest are critical to successfully regenerating and retaining oaks in future stands.  Herbicides are a very versatile, cost-effective tool that can be used in a variety of ways to help manage forest vegetation.  Manual herbicide application methods reviewed here are well suited for the small forest ownerships in the rugged Appalachians, where the use of mechanical methods and prescribed burning are often limited by steep terrain and fragmented ownerships. Some herbicide treatments methods also have the advantage of being very target-specific when treatments are restricted to species different from those considered desirable.  The effects of herbicide treatments on interfering vegetation can last for several years thereby providing slower growing seedlings like oak spp. time to develop and become competitive.  Four commonly used manual herbicide application methods used are reviewed here:  stem injection, basal spray, cut-stump, and foliar spray.  Recommendations on which herbicides to use, rates of application, and timing are also discussed.

     Application of midstory removal to enhance oak regeneration potential within uniform and irregular shelterwood systems


    John M. Lhotka, Jeffrey W. Stringer, Jared M. Craig, and Clinton P. Patterson


    Associate Professor (JML) and Extension Professor (JWS), Department of Forestry and Natural Resources, University of Kentucky; District Land Management Program Administrator (JMC), Ohio Division of Forestry; College Forester (CPP), Department of Forestry, Berea College


    Shelterwoods are recommended in the Central Hardwood Forest Region (CHFR) due to the intermediate shade tolerance and advance reproduction dependence of the region’s primary oak (Quercus) species.  Due to the widespread development of subordinate canopies dominated by shade-tolerant species, midstory removal is a typical component of shelterwood systems within the CHFR.  This work presents the effect of midstory removal on light availability and seedling development when applied following uniform and expanding-gap irregular shelterwoods.  Leveraged studies were completed in Kentucky on the Berea College Forest on intermediate quality upland sites.  One study documents the six-year findings within a uniform shelterwood and found that relative height and groundline diameter growth of oak were significantly greater following midstory removal than in the control but did not differ between natural and underplanted reproduction.  Second year results from a gap-based study indicated that midstory removal treatment and the distance relative to gap edge significantly increased understory light availability and groundline diameter growth of underplanted oak.  Together these studies support midstory removal as an approach for enhancing oak regeneration whether a shelterwood is applied uniformly across a stand or implemented using principles of irregular silviculture to increase structural complexity and microclimate heterogeneity. 

    Oak markets and timber resource, past present, and future


    William Luppold, Economist, Northern Research Station, USDA Forest Service


    Hardwood lumber and related product markets have been highly variable over the last 50 years but were influenced by timber availability.  Conversely, demand for hardwood products influenced the value of differing species and qualities of hardwood timber.  This presentation will first examine changes in consumption, production and price of hardwood lumber and related products over the last half century with an emphasis on the oak species.  We will then examine changes in the oak timber base and discuss how these changes may influence the future utilization and price of oak species.

    The Adaptive Silviculture for Climate Change Project: A scientist-manager partnership


    Linda Nagel, Courtney Peterson, Jim Guldin, Chris Swanston, Maria Janowiak, Brian Palik, Steve Jack, Seth Bigelow


    Department Head and Professor (LN) and Research Associate (CP), Forest and Rangeland Stewardship Department, Colorado State University; Supervisory Research Ecologist and Station Silviculturist (JG), Southern Research Station, USDA Forest Service; Research Ecologist (CS), Biological Scientist (MJ), and Ecologist (BP), Northern Research Station, USDA Forest Service; Conservation Ecologist (SJ) and Assistant Scientist (SB), JW Jones Ecological Research Center


    Forest managers in the United States face many challenges to sustaining critical ecosystems, including observed and projected climatic changes that require mangers to implement climate-adaptive strategies. Three common adaptive silviculture options discussed in the context of climate change are: creating resistance, promoting resilience, and facilitating forests’ response to change (i.e., transition). However, there is a lack of on-the-ground forest adaptation research to indicate what adaptation measures or tactics might be effective in preparing local forest ecosystems to deal with climate change, which can create challenges in translating these concepts into operational silvicultural prescriptions specific for individual forest types that vary in structure, composition, and function. The Adaptive Silviculture for Climate Change (ASCC) project was designed to translate these adaptation strategies into on-the-ground operational-scale research through a multi-region network of replicated sites testing ecosystem-specific climate change treatments across a gradient of adaptive approaches. Here we present the decision-making framework we employed to develop the suite of adaptation treatments for five contrasting forest types, highlight the implementation process used, and discuss contributions of this collaborative science-management partnership. Highlights will include a discussion of the variability in adaptation treatments developed by ecosystem type, looking specifically at oak management strategies in the longleaf pine coastal plain of southwest Georgia. Finally, lessons learned thus far from the study will be shared.

    The place of oak trees in forests of the United States


    Christopher M. Oswalt, Research Forester, Southern Research Station, USDA Forest Service


    Oaks are found across the globe. In fact, approximately 600 species have been identified worldwide. Native to the Northern Hemisphere, oaks are found from the cold latitudes of North America to the tropics in Asia and the Americas. In North America, oaks are widely distributed and found in both the western and eastern United States with two species common to both regions. Oak species richness in the eastern U.S. is highest in the South and generally declines as you travel north and west. Data from the USDA Forest Service Forest Inventory and Analysis (FIA) program were utilized to capture a snapshot of the current oak resource within the U.S. The FIA program has existed since the mid-1930s as the country’s pre-eminent forest inventory program. With over 350,000 plots across the nation on public and private land, FIA supplies a mechanism for identifying and tracking broad-scale patterns in forested landscapes. The FIA program collects data on plots distributed in a random, systematic fashion across the U.S. 

    Experimental Forests in the eastern United States and their contributions to mixed-oak silviculture


    Thomas M. Schuler, Project Leader and Research Forester, Northern Research Station, USDA Forest Service


    The Experimental Forests of the eastern United States and the people that work on them have played a foundational role in the development of mixed-oak silviculture and are a part of the history of forest science in North America. Early forest management practices were taught at the first forestry school in western North Carolina, referred to today as the Cradle of Forestry in North America.  Later this land was sold to the federal government and became the Pisgah National Forest. Then in 1925 the Bent Creek Experimental was established within the Pisgah and became the first Experimental Forest in the eastern United States.  Other Experimental Forests in Missouri, Indiana, Illinois, West Virginia, Pennsylvania and Ohio were established from 1934 to 1963 and provided research sites used for developing new guidelines for managing mixed-oak forests. Four different research priorities over the last half century have been addressed. These focal areas were uneven-aged management, even-aged management, fire ecology and management, and, most recently, climate resilience and adaptation.  This presentation will explore the people, unexpected outcomes, progress, and significance of this body of work that has formed the basis for modern and evolving mixed-oak silviculture to sustain this critical forest type that covers much of the eastern and central United States.   

    Variable retention shelterwoods to promote competitive oak seedlings in upland hardwood forests of the Southern Cumberland Plateau


    Callie Jo Schweitzer, Research Forester, Southern Research Station, USDA Forest Service


    The influence of residual stand density on understory light levels coupled to oak (Quercus) reproduction growth and competitiveness were examined under two-phase shelterwood prescriptions. In phase I of this shelterwood study, we reduced initial basal area in 25 percent increments using commercial harvests or midstory herbicide treatment. In phase II, after 8 growing seasons, all merchantable overstory trees were removed. One goal was to increase understory light to 20 percent of full sun to promote oak seedling growth over other species. The understory light increase after phase I was ephemeral and lasted 3 years for the herbicide, 25 and 50 percent retention treatments. Densities of large oak seedlings (greater than 4 feet in height up to 1.5 inches dbh) increased the most in the herbicide treatment and the 25 percent retention treatment, but this increase occurred primarily after phase II. Light levels in the understory after phase II were highest for the herbicide treatment, corresponding to the lowest stand density levels (19 SPA for all stems 1.5 inches dbh and greater) among all treatments. Four growing seasons post-phase II, sugar maple and yellow-poplar large seedling densities dominated those of oak in all treatments.

    Applied historical ecology of oak woodlands


    Michael C. Stambaugh, Daniel C. Dey, and Benjamin O. Knapp


    Associate Research Professor (MCS) and Assistant Professor (BOK), School of Natural Resources, University of Missouri; Project Leader and Research Forester (DCD), Northern Research Station, USDA Forest Service


    Woodlands are open-canopy forests with relatively high diversity of plant and wildlife species. Prior to Euro-American settlement effects, many different types of woodlands occurred across the U.S. in areas with recurring fire and / or grazing. Today, woodlands are rare and management focuses on restoring their structures, promoting characteristic tree species such as oaks and pines, and increasing biodiversity. Values of woodland management are diverse including wildfire risk mitigation, water yield and quality, and ecosystem resilience and resistance to pressures such as climate change and invasive species. The rarity of woodlands and the limited ecological understanding makes it difficult to envision their management requirements. To address these challenges, we present a synthesis of oak woodland ecology including definitions, biogeography, fire regimes, and historical ecology with an applied emphasis.

    Management of low-quality and degraded oak stands


    Jeffrey W. Stringer, Professor, Department of Forestry and Natural Resources, University of Kentucky


    Oak dominated stands, especially those in private ownership, have been subjected to a number of factors that have reduced and degraded current oak growing stocks, especially for timber products. The latter primarily caused by historical high-grading and diameter limit harvesting. Other anthropogenic factors such as wildfires, livestock grazing, poor logging practices and the lack of good management have also negatively impacted oak forests. The mesophication of eastern forests, negatively impacting oak recruitment, further erodes the ability to maintain quality oak growing stocks. Owners and practitioners face further challenges in building sustainability into these stands because much of the conventional silvicultural guidelines and prescriptions are designed to work in stands having adequate levels of acceptable growing stock, uniform canopy structures, and appropriate age classes and physiologic vigor, all of which can be suspect in degraded stands. To address these issues guidelines for properly assessing degraded stands, prioritizing degraded stands and stand attributes, along with a decision tree have been developed to aid developing appropriate silvicultural prescriptions to rebuild degraded oak stands.   

    Herpetofaunal responses to forest management: a synopsis of findings in oak-hardwood restoration forest stands


    William B. Sutton, Yong Wang, and Callie J. Schweitzer


    Assistant Professor (WBS), Department of Agricultural and Environmental Sciences, Tennessee State University; Professor (YW), Department of Biological and Environmental Sciences, Alabama A&M University; Research Forester (CJS), Southern Research Station, USDA Forest Service


    Amphibians and reptiles represent the vertebrate groups with some of the highest rates of global declines. A variety of stressors are implicated in these declines, but habitat destruction and unsuitable habitat management represent important threats. We leveraged a landscape-scale, oak/hardwood restoration experiment to evaluate the impacts of 6 forest restoration treatments (2 X 3 factorial design of 3 thinning and 2 burn treatments) replicated 3 times across the landscape on amphibian and reptile populations using standard drift-fence sampling techniques and radiotelemetry. Collectively, we found that amphibians and reptiles responded differently to forest restoration. Lizards displayed species-specific responses to restoration treatments based on a gradient of disturbance-dependence, where Eastern Fence Lizards (Sceloporus undulatus) responded positively to thin-with-burn treatments and Little Brown Skinks (Scincella lateralis) responded negatively in all restoration treatments. Terrestrial salamanders were not immediately impacted by management and displayed similar patterns of population fluctuation among restoration treatments. Radiotelemetry results for Copperheads (Agkistrodon contortrix) along with drift-fence captures of other large-bodied snake species revealed that incorporation of landscape context is important for management of these species. As our findings represent short-term responses of herpetofaunal populations, long-term monitoring is important to understand the impacts of repeated restoration disturbances.

    Inferring fire regimes from data you may already have


    Melissa A. Thomas-Van Gundy, Research Forester, Northern Research Station, USDA Forest Service


    Two methods used to map fire-adapted vegetation and fire regimes are presented and compared to the most recent LANDFIRE fire regime groups. First, a rule-based mapping method for locating fire-adapted vegetation using existing vegetation, potential natural vegetation, and ecological land types is explained. Secondly, a more direct method from mapped witness trees is presented. The results of these two methods on the Monongahela National Forest are compared to fire regime groups from LANDFIRE. A cell-by-cell comparison of the assigned fire regime groups shows the rule-based map to have about 56 percent agreement with LANDFIRE fire regime groups. The fire regime groups inferred from the witness tree data matched LANDFIRE on about 61 percent of the area. The methods described here are applicable to other landscapes and should be useful for others trying to define where to restore fire-adapted ecosystems.

    Crop tree management in fully and poorly stocked stands


    Jeffrey S. Ward, Chief Scientist, Department of Forestry and Horticulture, The Connecticut Agricultural Experiment Station


    Crop tree release (CTR), which focuses on growth on selected individual trees, is an alternative to area-wide thinning that diffuses growth across more trees within a stand. Our prior research found that (1) precommercial CTR increased diameter growth and upper canopy persistence of fully-released oak crop trees over a 24 year period without decreasing bole quality and or height growth. It also increased upper canopy persistence and diameter growth of partially released non-crop oaks. (2) Diameter and volume growth of pole and small sawtimber oaks were increased for at least twelve years by CTR. (3) Diameter growth of large oak sawtimber was increased by CTR with no loss of stand basal growth of oak sawtimber. These finding were the foundation of a study that examined alternative methods of rehabilitating high-graded stands at five study areas in Connecticut. Rather than a single stand prescription, a decision tree approach was used to assign small-scale treatments (~0.1 ac) to account for the irregular, spatially patchy structure of high-graded stands. Removal of low-quality residual trees together with CTR increased five-year diameter growth of sapling and pole crop trees. This approach has potential where commercial biomass markets exist or for landowners cutting their own firewood.