School of Forest Resources
The School of Forest Resources has enjoyed a 100-year history as the state’s lead research institution focusing on the evaluation, conservation, and management of forest-related resources. Our Forest Science faculty continues to interpret forest ecologies and the impacts of fire, disease, and invasive species. Allied research priorities are found in the management of hardwood forests relative to improved regeneration, ownership needs, and the aggregate landscape. Watershed management and water quality are added elements within the School's research focus.

The School’s forestry program was recently named one of the top ten best in North America by an Auburn University study published in the Journal of Forestry, which evaluated the research published by faculty members, how often this research was cited in other studies, and overall perceptions of the academic programs.

Parallel investigations of the ecology and management of wildlife and fishery resources are pursued by the Wildlife and Fisheries Science faculty. Their scientific objectives are to sustain and improve these resources for societal use, while maintaining an appropriate balance of species within various ecological settings.

Our Wood Products faculty endeavors to maximize the productive gains from wood resources and to further the energy attributes of wood and its manufacturing systems. Their perspectives encompass global markets and the business requirements of all such production entities.

The following summary provides examples of some of the research conducted by School of Forest Resources faculty in these areas.

Forest Ecology and Management

Our state’s forests have evolved over thousands of years or more. This resource is a complex ecological system, supporting both terrestrial and aquatic species, and having the dynamic character of changing its composition over time. In a parallel fashion, forest-related research evaluates the existing character and composition of the resource, and the interplay of various factors or elements that influence the forest over time. These investigative efforts can also establish appropriate management approaches to influence the yield of products and services, and the eventual ecological or aesthetic attributes of the future forest.

Within Pennsylvania and other eastern states, there is a noted expansion of red maple in the forests. This inroad has been made at the expense of oak species, which have suffered from gypsy moth attacks, other diseases, and ongoing harvests. This ecological transition was identified by Dr. Marc Abrams, professor of forest ecology, in an early treatise that identified red maple’s biological advantages within hardwood forests and its expansion within many of our eastern forests. Originally, because of its sensitivity to fire, red maple was relegated to the swamps. But with the gradual suppression of forest fires, red maple has emerged to take over upland sites and can be found on many of the landscapes in the eastern deciduous forest. Dr. Abrams also benchmarked earlier impacts imposed upon these forests by Native Americans in their casual use and management of certain forest and field settings.

Dr. Margot Kaye, assistant professor of forest ecology, believes that various forest types might be more effectively managed with controlled burns on a case-by-case basis. Her previous experience with western forests provides an interesting backdrop for using fire to encourage certain regeneration and growth responses found among various species within the collect of eastern deciduous forests. State officials are now looking at modifying liability laws to enable controlled forest burning.

In an effort to better define ways and means for sustaining oak species in their existing stands, Dr. Kim Steiner, professor of forest biology, and Dr. James Finley, professor of forest resources, established a longitudinal study of oak stand development within central Pennsylvania. One conclusion from their research is that conditions at the time of harvest play a major role in the development of the future oak stand. To achieve reliable regeneration, fencing of oak stands to keep deer out should occur before harvest. The study has also disproved a widespread notion that oak seedlings must be large at the time of overstory harvest in order to succeed in the next stand. Quantity can make up for size, because the forest environment is not homogenous. Some small seedlings start out in advantageous conditions and can survive the early battle for space.

With reference to developing actual management tools, Dr. Marc McDill, associate professor of forest resource management, has developed forest-management computer models now being used by the Pennsylvania Department of Conservation and Natural Resources’ Bureau of Forestry to guide tree harvests on 2.1 million acres of state forestland. The goal is to help the people who manage the forests do the best job that they can. The computer models show how things work in the forest over time. These models are based on data, and where actual data does not exist, assumptions are made based on the best information available. The models are explicit, and the assumptions can be changed to see how they affect the outcomes.

Using Dr. McDill’s software, foresters can determine the best approach for harvesting patterns among mature forests and the sequence of patterns over time, thereby shaping a desired forest for the future. “Right now, our forests are more or less the same age,” Dr. McDill says. “We need to get a better age distribution. Stands of trees might be even-aged, but the idea is to get a mix of stands across the forest. We are planning generations ahead.”

Dr. Eric Zenner, associate professor of silviculture, shares this interest in managing and planning for the future forest. Given the mature status of most of Pennsylvania’s existing forest, Dr. Zenner is evaluating the most efficient method by which old stands can be converted and regenerated to new stands, while, at the same time, maintaining the quality and diversity of these forests over time. This requires a synthesis of silvicultural information on the ecology of existing forests, their growing sites, the harvesting methods or biological phenomena surrounding their harvest or loss, and the regenerative probabilities of certain key species. Again, these efforts will require computerized models and an adaptation of spatial and temporal parameters toward the conversion process.

Wildlife Environments
Regardless of the cause of the shift in forest composition, these transitions affect the wildlife populations that are dependent on these habitat settings. Oaks and hickories supply many small mammals and birds with nuts and acorns. And the oak's rough bark—unlike the maple's smooth bark—houses bark-dwelling insects for insect-eating birds. The previously mentioned proliferation of red maple creates allied biodiversity concerns.

Dr. Margaret Brittingham, professor of wildlife resources, has evaluated the effects of forest loss on wildlife in terms of fragmentation of contiguous environments into smaller and less effective parcels. Various songbirds have lost significant breeding grounds through this attrition process. Seasonal migration routes may not provide the abundance of food that certain species rely upon in their fall and spring movements.

Dr. Margaret Brittingham and Dr. John Carlson, associate professor of molecular genetics, have found that a growing scarcity of black ducks is not due to habitat problems in northern nesting grounds, but rather to cross breeding with mallards. Since 1940 or so, hybridization of black ducks and mallards has resulted in fewer black ducks. The researchers conducted DNA tests on duck wings obtained from the Atlantic Flyway counts done by the U.S. Fish and Wildlife Service. The testing indicated that historically mallards and black ducks were very different genetically, and have become much more similar in recent decades due to hybridization. "Because the mallard population is so much bigger to begin with, the effect is greatest on the black-duck population,” explains Dr. Brittingham. In looking at the DNA of modern specimens, black ducks are no longer very distinct from mallards, and we are losing the unique species known as the black duck.

Dr. Chris Goguen, senior lecturer, recognizes a certain advantage in having a diversity of habitat types outside of forests to encourage the variety of songbird species found in our eastern states. In particular, open grasslands that follow strip mining have proven to be a major asset for various sparrows and other ground-nesting species. Similar benefits have been identified for large mammals, including Pennsylvania’s unique elk herd, now numbering near 800 animals.

Dr. Walter Tzilkowski, associate professor of wildlife science, in conjunction with Dr. Charles Strauss, professor of forest economics, and Dr. Bruce Lord, senior research assistant, evaluated the increasing size of this elk herd and its ramifications for tourism within northcentral Pennsylvania. The combination of forests and grassland complimented herd growth but the pressures of added tourists on small communities introduced new social problems. Accordingly, the herd size was stabilized through special hunting seasons monitored by the Pennsylvania Game Commission.

Decades of selective browsing by an overpopulation of white-tailed deer has caused an increase in species such as hay-scented ferns, which compete successfully with tree seedlings, according to Dr. Gary San Julian, professor of wildlife resources. He believes it is clear that where deer are most numerous, seedlings are devoured before they can grow out of reach of voracious whitetails.

However, Dr. San Julian concedes it is likely that several factors are contributing to the change in forest composition in Pennsylvania. “It may be that decades of fire suppression, acid rain, and deer damage have all combined to create an environment that is not favorable to red oaks and a few other desirable tree species.”

Measuring deer impacts on relatively small blocks of forestland is not a new concept, with scientists repeatedly making intensive measurements of tree regeneration. But developing an accurate, cost-effective technique for using these measures across a broad scale to help make management decisions for hundreds of square miles of forest is new. Dr. Duane Diefenbach, adjunct associate professor of wildlife and associate unit leader of the Pennsylvania Cooperative Fish and Wildlife Research Unit, is working on that.

Dr. Diefenbach, his colleagues in the School, and his most dependable students walked transects—with the aid of geographic system technology—and counted plants. They tallied wildflowers that deer prefer, such as Canada mayflower, jack in the pulpit, Indian cucumber, and trillium. “Even if you don’t believe over-browsing is an issue in Pennsylvania forests,” Dr. Diefenbach elaborates, “at least we are starting to look beyond deer numbers and trying to find ways to assess habitat conditions as they are most relevant to deer.”

Wood-based Energy

Trees may be the key to the state’s energy future. Wood products experts Dr. Charles Ray, Dr. Paul Blankenhorn, Dr. Nicole Brown, Dr. Jeffrey Catchmark, and forest economist Dr. Charles Strauss contend that concentrating on a sustainable harvest of smaller, under-utilized “remnant” trees could yield a huge amount of ethanol.

Pennsylvania’s forests are rich in potential bioenergy from small-diameter trees that are overcrowded and underutilized and that inhibit the opportunity for professional management. Using the U.S. Forest Service’s most recent Forest Inventory Analysis data for Pennsylvania, the Pennsylvania Hardwoods Small-Diameter Task Force recently estimated that as much as 500 million tons of wood are held in these small-diameter stems. Annual sustainable harvest of six million dry tons of wood per year could be converted into various bio-energy sources.

According to Dr. Charles Ray, assistant professor of wood products operations, six million dry tons per year is the rough equivalent raw-material usage of 18 wood ethanol plants producing 540 million gallons of ethanol per year. He thinks the potential for Pennsylvania—and especially the state’s heavily forested northern tier—is huge.

Dr. John Carlson, associate professor of molecular genetics and director of the Schatz Center for Tree Molecular Genetics, also is studying the use of trees for biomass. He served on a steering committee for the International Poplar Genome Consortium, which helped the U.S. Department of Energy chart a path for the ground-breaking genome sequencing of the poplar tree. Populus was chosen as the first tree genome to sequence due to its rapid growth rate, small genome size, and widespread use in plantation forests.

“The sequencing of the poplar genome is a bonanza for researchers seeking to understand how individual genes influence the growth of trees and their adaptation to the natural environment,” Dr. Carlson explains. “We are trying to apply this knowledge to the breeding of fast-growing trees capable of producing wood, fiber, and energy on a smaller amount of land.”

But before biofuels can be made in any quantity from woody plants such as trees, scientists must learn how the cell walls can be broken down so that the plant’s constituent sugars can be converted to an alcohol such as ethanol.

Dr. Jeffrey Catchmark, a faculty member with a shared appointment in the College of Agricultural Sciences and the College of Engineering, and colleagues are using novel atomic force micrcoscopy techniques to study the role that substances called “expansins” play in cell walls. Dr. Catchmark explains, “It’s a promising line of inquiry that might yield new insights into the structure of the plant cell wall, which would be useful in the design of new cellulosic materials. The idea is that someday we might genetically modify plants for ethanol production.”

Dr. Nicole Brown, assistant professor of wood chemistry, also is wrestling with the question of how to break down the cell walls of woody plants. Collaborating with other Penn State researchers, she has been pulled into biomass research because of her expertise on how wood polymers behave. Polymers are long strings of molecules that determine the structure of materials such as trees.

“After plants are genetically manipulated to produce different kinds of enzymes and proteins, we study how those compounds affect the properties of plant polymers,” Dr. Brown says. “The thought is that these protein and enzyme-based modifications will make the woody tissue easier to disassemble. That will make it easier to access the sugars that will make ethanol.”

Traditional Strengths of the Wood Industry
Dr. Bruce Lord identified Pennsylvania’s wood industry as having annual shipments amounting to $16.6 billion and an estimated total annual economic impact of $27.7 billion statewide. Much of this gain can be attributed to manufacturers in the more rural counties, where there is immediate proximity to high-value timber. But these regions are also augmented with an excellent workforce.

Dr. Judd Michael, associate professor of wood products business management, has identified various performance levels and skill sets indigenous to this labor force and has further identified ways and means for sustaining the integrity of their output and enhancing the management-labor communication network. Dr. Michael has further established outreach programs for this industry group aimed at improving the employment capabilities of this work force and building greater rapport with employees.

Dr. Paul Blankenhorn, professor of wood technology, has focused much of his research on the processing needs of this industrial group, particularly from the standpoint of gaining efficiencies in the lumber drying process, evaluating wood emissions, and gaining greater yields from the timber resource. His work has provided considerable gains to industry with reference to advances in kiln schedules for Pennsylvania’s valuable hardwood species and appropriate means for reducing possible injurious emissions from oak species. Recent research on small-diameter hardwood logs underscored probable gains in certain sizes and species, added costs and degrade, and allied net results.

Earlier research on using red maple to manufacture laminated bridge members for secondary road applications was spearheaded in the early 1990s by Dr. Blankenhorn, Dr. John Janowiak, professor of wood products engineering, and Dr. Harvey Manbeck, professor of agricultural engineering. Their concerted efforts brought forth proven designs for such structures, national design standards, and the completion of several trial bridges within central Pennsylvania. Their work also led to incorporating red maple beams within the new Forest Resources Building.

Dr. Paul Smith, professor of forest products marketing, initiated research on extruded wood-plastic composites (WPC) as advanced products for the rather docile residential decking to the more demanding requirements of wharfs and piers along salt water settings. This project, funded by the Office for Naval Research, is a joint project with Wood Materials and Engineering Laboratory at Washington State University and Penn State’s Wood Products program, has successfully combined natural wood fibers and thermoplastic polymers. WPC products combine the favorable performance and cost attributes of wood with the processing characteristics of thermoplastic polymers. This past fall, the new and innovative structural WPC profiles developed by this research project were used to build a deck on the green roof of the new Forest Resources Building.

Water Resources
Pennsylvania is home to more than one million private water wells, and more than 20,000 new wells are drilled each year. Pennsylvania is also one of only three states that have no guidelines on the location, construction, and maintenance of private wells, so all aspects of private-well management are voluntary and up to the respective well owner.

School researchers are collaborating with the Pennsylvania Water Resources Research Center to determine the characteristics and management of private wells and to gather opinions of homeowners with wells. Bryan Swistock, water resources specialist for Penn State Cooperative Extension, is inviting well owners to complete an online survey.

Previous studies have shown that about half of all private wells sampled fail to meet at least one drinking-water standard. Especially common problems in wells are bacteria, low pH, lead, and iron. As more and more wells are drilled around the state, the concern is that poorly constructed and managed wells will become a bigger problem.

The survey is just part of the research. Investigators also are testing the water quality in 700 wells across the state. The well-testing segment of the study is being funded by the Center for Rural Pennsylvania. By comparing survey answers and actual
water quality, a clearer picture of drinking-water safety should emerge.

Because all aspects of private well location, construction, and management are voluntary, little is known about these water supplies and how they perform for homeowners, Mr. Swistock points out. "This makes it difficult to create educational programs to meet the needs of existing and future well owners," he says. "We are trying to get a handle on the quality of Pennsylvania's private wells and educate homeowners about the need for proper care."

Fisheries Science

Researchers in the School conducted a study to determine if the millions of nonnative trout stocked for Pennsylvania anglers have affected the state's native aquatic organisms. Nonnative trout have had obvious detrimental impacts on native fish, amphibians, and invertebrates elsewhere, so researchers in the School wondered if brown and rainbow trout stocked by the Pennsylvania Fish and Boat Commission affect the state's stream life differently than native brook trout.

Dr. Jay R. Stauffer, Jr., distinguished professor of ichthyology, and then doctoral student Caleb Tzilkowski conducted a study that considered brown trout effects because rainbow trout rarely establish breeding populations in Pennsylvania. Brown trout, on the other hand, spawn in many Commonwealth streams and wild populations are common. It is not unusual for wild browns and brook trout to coexist in the same headwater stream. Many wild brook trout populations have been there for thousands of years, whereas the wild browns are descendants of stocked fish that were able to survive and reproduce.

This study suggested that although brown trout and brook trout are important predators in headwater streams, their effects on the studied food webs were very similar.

Data was also gathered for another study aimed at restoring endangered shiner populations in the Brodhead Creek watershed in Monroe County. Trout have been stocked each spring into the only stream (Marshalls Creek) where the endangered shiners occur in the state, and because shiners are known to be excellent trout bait, the researchers took an interest in how many of the endangered shiners stocked trout eat. Stomach contents of stocked brook and rainbow trout and wild brown trout from Marshalls Creek were identified. The results suggested that stocked trout do not pose an immediate threat to nongame fishes, but introduced trout that become established may.

While many fish population studies focus on species existing in exploited systems, data on unexploited fish populations can provide useful insight for fishery managers. Dr. Paola Ferreri, associate professor of fisheries management, conducted a study to describe the structure and dynamics of the unexploited yellow perch population in the Pymatuning Sanctuary in Crawford County. The age and size structures were found to be dramatically different for males and females collected on the spawning grounds. The abundance of small males collected is consistent with data from exploited systems, but the number of large, older females collected seems unique to unexploited systems. This research provides realistic boundary conditions for mathematical models that describe the response of yellow perch populations to different management strategies.

A Composite View
As these research snapshots illustrate, the School of Forest Resources is engaged in a broad array of research topics. This should be expected, given our academic programs in Forest Science, Wildlife and Fisheries Science, and Wood Products and the required sets of disciplines found within each of these majors. However, the common point of view to all of these research efforts is a genuine appreciation of the forest resource setting and a fervent interest in perpetuating this resource for the continued enjoyment by all of society.