The lush forests of Pennsylvania have long been an important source of pride and sustenance for both the environment and the economy. However, this delicate balance can only be maintained through thoughtful forest management practices, especially in the context of timber harvesting and subsequent reforestation methods. As a landowner, harvesting timber responsibly and sustainably not only supports your economic needs but also plays an important role in promoting healthy forests.
We have previously talked about sustainable timber harvesting in Pennsylvania. In this article, we will delve into how we can achieve healthy reforestation and regeneration of the Pennsylvanian forests.
Managing Competing Plants, Sunlight, and Wildlife
As a forest owner who wants to achieve a successful reforestation of their forest land after harvesting, you need to be familiar with the management of three crucial factors that affect the regeneration of forest stands: Competing Plants, Sunlight and Wildlife. Although the management of all of these factors together is the key to sustainable forest regeneration, let’s look at each of them separately to understand them better.
1. Managing Competing Plants:
Competing plants are undesirable plants that compete with the seedlings and saplings of your desired species in terms of nutrients, light, space, and water. This inhibits the germination, growth, and development of the desired tree species. In Pennsylvanian forests, the common competing plants include spicebush, striped maple, ferns, grasses, American beech, ironwood and mountain laurel. Many competing plants have a faster growth rate and spread very quickly. They are called invasive plants.
The management of competing plants can be done in two ways: Mechanical and Chemical treatments. Mechanical treatment includes methods like cutting, pulling, ploughing, prescribed burning, etc. Mechanical methods can be time-consuming, and costly and the plants can resprout later.
Chemical treatment on the other hand is cost-effective, easy to administer and more effective. This includes using prescribed amounts of herbicides to kill off the competing plants. Although there is some reluctance to use chemical products from an environmental perspective, there are now low-risk and effective herbicides available.
2. Managing available sunlight:
Different species of tree species have different requirements of sunlight or shade and that determines their shade tolerance. Shade tolerance is the categorization of tree species into intolerance, intermediate and tolerance based on the optimal amount of sunlight they need to germinate and develop.
|SHADE TOLERANCE OF COMMON PENNSYLVANIA TREE SPECIES|
|White Ash||White Oak||Basswood|
|Black Cherry||Basswood||Red Maple|
|Hickory||American Elm||Sugar Maple|
|Yellow Poplar||Eastern White Pine||American Beech|
|Sycamore||Northern Red Oak||Eastern Hemlock|
Managing the light penetrating through the forest canopy to the forest floor is done while performing harvesting and thinning operations. Harvesting techniques such as single-tree selection method, group selection, shelterwood system, and clearcutting are used by foresters depending on the shade tolerance of tree species.
Single-tree selection method of harvesting is used for promoting the growth of shade-tolerant species where trees across all diameter classes are selected for harvest. Since this only creates a minor opening in the forest canopy, shade-tolerant species can germinate and develop in low-light conditions.
Harvesting using a group selection system creates small openings on the forest canopy that let in light on those patches which induces regeneration of trees. Depending on the size of the openings, shade-intolerant species can grow in the center while intermediate and shade-tolerant species grow on the edges.
The shelterwood system promotes the natural regeneration of trees by leaving behind shelter trees which act as mother/seed trees. These trees, along with providing seeds also establish favorable conditions for seed germination such as partial shade, moisture, and cool temperature. Once the regeneration develops up to a certain height, the retained trees are removed.
Clearcutting is practiced if the new regeneration is going to be shade-intolerant species that grow best in full sunlight. Ideally, numerous regenerations should already be present on the forest floor for natural regeneration.
3. Managing Wildlife
Wildlife, mostly deer, has been a major problem for the healthy regeneration of the Pennsylvania forests. By selectively browsing certain tree species, deer can severely reduce the number and quality of tree seedlings in an area. Unlike other factors like competing plants and sunlight, deer are harder to manage since they are free-roaming, and their population can sharply increase if uncontrolled.
Fencing has proven to be the most effective measure against browsing by deer, but fences of forest stands can be very expensive to establish and even more expensive to maintain. Forest owners in Pennsylvania can take assistance from The Pennsylvania Game Commission’s Deer Management Assistance Program (DMAP) to tackle this problem.
Pros and Cons of Natural Reforestation
As a Pennsylvanian forest owner, it is important to understand that the forest types found here mostly regenerate naturally through the natural dispersal of seeds or through sprouting from stumps and roots. Moreover, studies also suggest that naturally reforested stands grow faster and better than manually reforested ones in Pennsylvania.
Besides being favorable for the Pennsylvanian forests, natural regeneration tends to be more cost-effective than manual methods of reforestation if proper silvicultural methods are followed according to a proper forest management plan. As the importance of biodiversity and natural systems keeps increasing with the changing climate and biodiversity, natural regeneration, which mimics the natural processes of the establishment of a forest stand is also favored over manual planting.
However, there are several tradeoffs and uncertainties when regenerating forests naturally. One of the significant ones is that it is harder to control the species composition of the forest stand since competing and invasive plants can take over and outcompete the desired species. Also, even among the seedlings of the desired species, excessive competition can result in a slower growth rate and degradation of the tree form and timber quality. It is also harder to protect the young seedlings from damaging agents like insects, drought, fire and wildlife.
Despite all these challenges, the forests of Pennsylvania continue to be replaced with naturally regenerated seedlings since it is the most cost-effective and efficient reforestation method.
Manual Reforestation in Pennsylvania
In Pennsylvania, manual reforestation using planting seedlings or dispersing seeds is only performed in some cases like reforesting abandoned strip mine locations, former agricultural fields, river areas, and areas with no seed source. However, in pine plantations, planting nursery-grown, and treated seedlings is also a common practice. Also, manual reforestation using seedlings is crucial to re-introduce lands with tree species like the American Chestnut trees that have decreased in number in Pennsylvania but were historically abundant in the region.
Manual reforestation is also done when you want to re-establish native species that may no longer be present on your property or if the number of desired seedlings is very low to establish a stand. However, manual reforestation is normally prescribed as a supportive method rather than the primary method of reforestation.
Timber harvest aftercare is a critical aspect of the reforestation process. Natural regeneration of the harvested tree stand remains the most appropriate and common way of reforesting lands in Pennsylvania. However, young tree seedlings are vulnerable to a variety of stressors, including competition from other vegetation, deer browsing, and light conditions. Proper management techniques are required based on the type of desired tree species.
Reforestation is a complex endeavor that requires expertise in forestry, ecology, and land management. For landowners in Pennsylvania, partnering with certified foresters and forestry service providers is essential. These professionals can assess the unique characteristics of your land, develop tailored reforestation plans, and guide you through the post-harvest care needed to ensure the success of newly planted seedlings.
Contributed by Sandesh KC