The Future of Oak is in Your Hands

By Dave Apsley, Extension Natural Resource Specialist, Ohio State University
and
Dave Jackson, Forestry Educator, Penn State Extension 

Why is Oak So Important?

Responding to this question is a difficult task since oaks are important for so many reasons, and there are valid concerns about their future. I will share just a few examples of the importance of oaks for wildlife and the forest products industry in this article.

This quote from William McShea and William Healy (2002) sums up the importance of oak for wildlife: “Acorns are the most important wildlife food in the deciduous forests of North America, the ecological equivalent of manna from heaven.” Acorns are a high-energy food source that stores well. As a result, they are a key food source that helps wildlife populations survive winter when food supplies are most limited. More than 90 wildlife species from songbirds and small rodents to white-tailed deer and black bear use acorns. Even animals that do not directly consume acorns can be positively affected by oaks. Some of these relationships are obvious, for example, many of the small mammals that carnivores (like bobcats) feed on have a diet of acorns. While others are not as obvious. For example, ponds and vernal pools with oak leaf litter produce more and larger wood frog tadpoles and salamanders than those with mostly maple litter.

The wood from oaks is used in many applications, but most people think of flooring, cabinetry and furniture. The most recent data from the U.S. Forest service shows that 25% of the volume of wood harvested in Pennsylvania comes from oaks (Forest Inventory and Analysis 2016). Additionally, a huge percentage of the lumber consumed in the Amish Furniture industry is oak. One historic use of white oak is cooperage (barrels). White oak barrels have had many uses, but there has been a recent resurgence in demand for use in the wine and spirits industry which has resulted in an increased demand for white oak lumber.

Why are we concerned?

Currently, about 47% percent of Pennsylvania’s 17 million acres of forest is classified as

Oak/Hickory. Although oaks dominate the upper canopy of much of our forests, there is a serious lack of smaller oak seedlings, saplings and pole sized (4-10 inches diameter) trees to replace them. Instead, the trees getting established under the oak canopies are mostly red maple, black birch, sugar maple, and blackgum. In fact, understory abundance of species like red maple, American beech, blackgum, striped maple, and black birch is increasing. When forests are disturbed, either by natural or human-caused events, the existing understory species have the potential to change the composition of the next forest. In fact, the volume of maples (red and sugar combined) has increased to the point that they are nearly equal to red oak.

Why is this happening? 

Oaks are a bit like Goldie Locks. Too much light from heavy cutting (clear cutting) and they often lose the battle to sun loving species like yellow poplar, aspen, and black cherry; too little light from no cutting or light cutting (select cutting) and they lose to shade loving species like red and sugar maple, blackgum, and black birch. However, when young oak seedlings receive just the right amount of light they can invest much of their energy into the development of large carrot-like roots. These roots give them the ability to sprout and grow rapidly following disturbances like fire, wind throw events, and timber harvesting. 

In addition to light, browsing by deer also has a significant impact on the presence of oak seedlings in forest understories. Deer have taste preferences; some trees, like oak, are highly preferred while others are hardly touched. By selectively browsing oak, deer have the ability to eliminate it from forest understories. Research has shown that when deer population densities exceed what the land can support oak regeneration suffers. In regions of the state where decades of overbrowsing have severely depleted the habitat, even relatively few deer can have significant effects.
  
What is being done about it?

The Northern Research Station of the U.S. Forest Service and Penn State University have been conducting oak research for more than 20 years. The focus of the research has been on regenerating and sustaining oak forests. In a nut shell what they are finding is that eliminating much of the mid and understory poles and saplings (mostly red maple, striped maple, black birch, and blackgum) with herbicides (or fire) is not enough for oak seedlings to become established. However, when combined with a harvest that allows the proper amount of light to reach the forest floor (i.e. shelterwood harvest) and deer reduction or fencing, oaks can be successfully established on many sites. These practices are currently being employed on public lands across Pennsylvania; however, they are rarely employed on private woodlands, which make up nearly 70% of Pennsylvania’s forests.

In 2017 the PA Natural Resource Conservation Service (NRCS) and the Allegheny National Forest received funds for the 1st year of a 3 year project to improve and protect the health and resiliency of Oak ecosystems in North-Central Pennsylvania. The project, entitled “Sustaining Pennsylvania’s Oak Ecosystems through Partnership in Forest Management,” covers a 15 county area in North Central Pennsylvania. The project is a partnership between NRCS, the Allegheny National Forest, the Pennsylvania Game Commission, and the Pennsylvania Department of Conservation and Natural Resources Bureau of Forestry. The collaboration will help public and private forest landowners maintain a diversity of forest age classes and species to sustain forest ecosystems that are resilient to stressors. For additional information contact your local service center.

The future of oak is in your hands!

If you would like to enhance oaks in your woods be sure to contact your DCNR Bureau of Forestry Service Forester or a Penn State Extension Forestry Educator to get assistance. Oaks were here in the past, and they're here now. Help us to make sure that they are here in the future.