After evaluating your site characteristics based on the species and terrain (Managing the Right Species on the Right Site: Part 1, Site Selection), you should plan how to regenerate the next stand. Some of these decisions can be made at least 10 years before a commercial harvest to allow time for favorable trees to establish in the understory. You can regenerate a stand by replanting trees after harvest or by managing the site so that trees regrow naturally. Picking the right management strategy prior to a harvest can save you money and provide an optimal future income for you and your heirs. This publication describes different types of harvesting appropriate for the management of specific species.

While many trees have niche uses, this publication focuses on high value species typically grown for timber in North Carolina. Table 1 lists the most common timber species and their tolerance to shade. (Table A-1 in the Appendix provides a more comprehensive list of the state’s commercially valuable timber species). The species described here require proper management techniques to regenerate either naturally or via planted seedlings.

¹Shade intolerant = needs full sun to grow. ↲

²Intermediate tolerant = generally can establish with some shade but needs sun in the canopy to grow to maturity. ↲

³Shade tolerant = can grow in dense shade. ↲

To plan an appropriate management strategy for your forest, enlist a consulting forester or a forester from the North Carolina Forest Service to write a forest management plan for your property. This plan should address your species composition, tree age, site quality, and soil characteristics and provide a timeline for future management.

A slope steepness of more than 30 percent may limit forest management activities. Steeper areas must be cut either by hand or with specially designed machinery, which increases harvesting costs. Increased costs of harvesting limit lower-value harvest such as thinning pine. Thinning is often required to grow higher value pine sawtimber. If profit is the main objective, you should be careful about investing money in areas that will be difficult to harvest in the future.

The Web Soil Survey and USGS Topo Maps are tools that can help landowners and land managers decide what terrain is easily accessible for future management. Extension publication WON-64-1, Managing the Right Species on the Right Site: Part 1, Site Selection describes how to compare different sites based on soil characteristics.

Other site limitations can include access to markets, property access, available contractors, and property size. A forest management plan can address each of these considerations and help you make the most informed decisions. See AG-890, Management Plans: A Planning Guide for Landowners for more information.

A harvest is done in a way that promotes a stand of new trees either naturally or by planting. Table 2 describes the harvest and regeneration methods for some common commercially grown tree species.

A clearcut harvest regenerates sun-loving, shade-intolerant species such as pine, yellow-poplar, and various bottomland hardwood trees.

A seed-tree harvest retains a few trees (about 10 per acre) to provide seed to regenerate pine naturally. This type of natural regeneration can be supplemented with planted seedlings.

Shelterwood harvesting is a multistage system that relies on shade from large trees to control which species can establish and grow. A shelterwood harvest can include a midstory removal initially to provide enough light for young oak seedlings to germinate and grow from seed and a burn regime or herbicide application to control fire-intolerant species. Once new seedlings are considered advanced regeneration (over 4 feet tall), a more intensive harvest can take place to remove some or all of the overstory trees to allow the young oaks to grow quickly. Foresters must strike a balance between harvesting enough trees to provide an acceptable profit and maintaining the proper conditions for regenerating oak. After the overstory removal, the young oak seedlings should quickly resprout and grow faster than other shallow-rooted trees (such as red maple, beech, and yellow-poplar). A follow-up “release” treatment—in which competing trees immediately surrounding the best oaks are killed—will allow the oaks to thrive and grow to maturity.

In an expanding gap system, a logger will clearcut harvest 1- to 2-acre gaps to encourage oak to regenerate naturally on the edges. With moderate light, oak will typically seed in on the north side of the gaps. In about five years, the overstory trees on the edges of the gaps can be removed, thus “expanding” the gaps where oak seedlings can thrive. Once established, oak can handle the higher light conditions of an open forest. Popular in Europe, the expanding gap system is currently being used in North Carolina on select sites in Pisgah National Forest and on state and private lands. Though not common yet in the United States, this system shows promise for establishing oak across more sites. Researchers and practitioners are investigating the profitability and success of this system here. The expanding gap system requires a forest manager to carefully mark trees, and the forest must be large enough to allow small openings while still providing enough timber to be profitable. As oak continues to become more valuable, understanding multiple harvest systems will be essential to establishing new oak stands.

* Additional forestry activities may be needed, including a prescribed fire and/or release of the best “crop” trees. ↲

+ Site prep may be needed to allow the stand to be regenerated successfully. This could include heavy machinery to clear brush, bedding, ripping, burning, or spraying herbicide. ↲

There are many ways to regenerate trees for a productive stand in the future—by relying on natural regeneration via stump-sprouting or self-seeding or by planting tree seedlings. Table 2 describes the types of harvest that would be required to regenerate your stand, whether you plant trees or allow natural regeneration.

Pines are the most common trees planted for regenerating forests after a clearcut harvest. Pines grow quickly, have excellent survival rates, and grow well on a wide range of sites. Commercial nurseries provide genetically improved seedlings that are treated to deter deer browsing and attack by the pales weevil. Decades of forestry research have been invested into improving the growth rate, form, and survival rate of North Carolina’s four main commercial pine species—loblolly, shortleaf, longleaf, and white pine. Planted pines outperform naturally regenerated pines on most sites.

Hardwood seedlings may be planted to fulfill both timber and wildlife objectives. Hardwoods are commonly planted in fields in wet or bottomland areas. A mixture of species can be planted in fields to accommodate a wide range of goals, including provision of trees for future timber harvest, production of nuts and fruit, and attraction of pollinators. For a diverse plantation, acceptable hardwoods can be interplanted with either similar hardwoods (for example, a mix of oak species) or with shrubs that can be grown within the midstory and understory.

Pines to Plant

Loblolly Pine—This species is suitable for a wide range of sites in the piedmont, coastal plain, and foothills of the mountains. It grows fast and is relatively cheap to replant. Site preparation costs are minimal, and trees have a high survival rate. Loblolly pine will typically bring in the highest return on investment, if the site is favorable. This species has been genetically improved over time and is currently offered as second- or third-generation seedlings. Breeders select pine seedlings for their growth performance, resistance to fusiform rust, and stem quality. Improved seedlings vastly outperform unimproved seedlings on almost all sites. Ask for the PRS™ sheet when purchasing seedlings. This document tells you how quickly the trees will grow compared to unimproved seedlings (Performance), their resistance to fusiform rust (Rust), and their stem form (Stem).

Shortleaf Pine—This species was historically widespread throughout most upland sites in North Carolina. Shortleaf pine is commercially grown in the piedmont and mountains. Site preparation is required prior to planting—this could include a site-prep burn or herbicide spray to clear away competing species.

Shortleaf pine grows slower than loblolly pine for the first 30 years, then faster afterward. It performs well in mixed pine and hardwood stands. Mixed stands are highly diverse and can allow favorable species to grow together. Shortleaf pine typically has excellent form—straight and tall with few to no lower branches. Little leaf disease, which damages the roots, can be an issue on some sites.

Longleaf Pine—This pine species is suitable for the sandhills area and is the only timber species option for sites with deep, sandy soils. Longleaf pine is commonly planted to restore the historic longleaf ecosystem in the coastal plain. Longleaf was historically used for pitch and tar products, and the timber was used in ship masts. Growing longleaf pine with a longer rotation than loblolly pine (50 to 80 years) allows for pine-straw raking and provides large, high-quality sawtimber that can bring a high return on investment.

White Pine—This species is a good option for the mountains. It has a rotation length similar to yellow-poplar (40 to 50 years). White pine can be grown in a monoculture plantation or, on some sites, with yellow-poplar. It is sometimes grown for Christmas trees. White pines that lack hardwood competition can have their branches tipped for holiday wreaths starting at 7 years old. Plantations can produce two to three tip cuttings over a four-year period.

Other Commercially Valuable Conifers—There are a few very site-specific pines and other conifers that can be planted in areas in either the mountains or the coast. Table mountain pine is an option in specific exposed, high-elevation sites in the mountains. Pitch pine can be planted in mountain bogs and wet areas. Pond pine, bald cypress, and Atlantic white cedar are limited to wetland areas in the coastal plain. Bald cypress and Atlantic white cedar plantations have been shown to be effective in restoring areas where seedlings do not naturally establish after a significant disturbance, such as hurricane damage, a large clearcut, or wildfire. Effective planting requires site preparation such as bedding and spraying.

Hardwoods to Plant

Oaks—Oaks are site-selective and have relatively low survival rates due to high competition from other species. Oak species should be matched with a favorable site based on hydrology. Moisture-loving oak species (for example, swamp white oak, swamp chestnut oak, and cherrybark oak) can be planted in bottomlands, while species that need dry conditions (for example, white oak, northern red oak, and scarlet oak) can be planted on side slopes or ridgetops. Oak can be planted after a harvest to supplement natural regeneration. Choose seedlings with a well-developed root system, which are much more likely to survive than small seedlings with limited roots. Planting is usually combined with herbicide spraying to control grasses and other competing weeds. Planted seedlings require weed control for the first three to five years.

Yellow-poplar—Planted yellow-poplar seedlings require full sun and control of competing species for the first three to five years. Planting should be restricted to well-drained sites like open fields. While yellow-poplar can grow in bottomland sites, the species does not do well with regular flooding.

Sycamore and Hybrid Poplar—These species are being evaluated for growing together in dense spacing to produce woody fiber that can be used for energy production or jet fuel. These trees can be reliably planted on an old field with low nutrients and poor soil drainage and harvested for fiber in three to seven years.

Mixed Pine and Hardwood

A mixed stand is typically defined as one that has 25 to 75 percent pine trees by number of trees or stocking. These stands grow slower but are typically highly diverse, allowing for multiple timber products to come from a harvest. These stands also may be more resilient to any one insect or disease. Pines can be resistant to pests that defoliate hardwoods, while hardwoods are resistant to common pine pests.

Mixed stands are established by either planting pine in a forest after a partial harvest such as a shelterwood harvest or planting pine at a wider spacing after a clearcut harvest—the latter with minimal site prep. Hardwood seeds in the soil sprout and become established, growing alongside the wide-spaced pines.

Growth of mixed stands can be manipulated over time by converting a pure pine stand into a two-aged mixed pine and hardwood stand—with younger hardwoods growing underneath mature pine. This management is achieved by heavily thinning the pine, usually in combination with prescribed fire regimes. Successful repeated prescribed burns kill shallow-rooted, thin-bark hardwoods such as young red maple, beech, and sweetgum to provide room for deeply rooted oak seedlings. In favorable soil, oak can establish underneath pine stands due to indirect light that filters through the canopy. An oak seed source must be near the stand to establish in the newly opened pine forest. Otherwise, seedlings will need to be planted underneath the thinned pine.

Many species require some site preparation after the harvest to either give tree planters space to plant trees or to clear existing vegetation that might outcompete the planted trees. A forester should be hired to determine what site preparation will be needed immediately after the harvest. This up-front expenditure can ensure the seedlings will survive and grow quickly, producing a faster return on the reforestation investment.

The amount of preparation necessary is site-dependent. Typical site-preparation techniques may include herbicide application to kill competing vegetation, a controlled burn to remove remaining woody debris, the addition of bedding in wet areas to prevent the seedlings from being flooded, and the use of heavy machinery to chop down vegetation prior to a spray. Site-preparation contractors may use a drum chopper or heavy disks to remove small vegetation.

Spacing of planted pines typically ranges from 8x10’ to 12x12’, equivalent to 544 to 302 trees per acre, respectively. In areas with a stronger market for pulpwood, landowners can expect pine to be commercially thinned when the trees become suppressed. In areas with no or very little pulpwood market, landowners should plant on wider spacings. This will allow the trees to be larger at the first thinning or eliminate the need for thinning. Acceptable wide spacing could be 10x10’ (435 trees per acre) or 10x12’ (363 trees per acre). A fully stocked pine stand should have a minimum of 303 free-to-grow trees per acre that can grow to the first thinning. Foresters plan on a 1-year survival rate for loblolly pine of 80 to 90 percent. Survival rates may be higher with optimal site prep, containerized seedlings, and favorable weather conditions after planting.

The spacing of planted hardwoods can range from 6x6’ in cluster plantings beneath a gap in the canopy (1,200 trees per acre) to 12x12’ or 15x15’ (302 and 193 trees per acre, respectively) in open fields. Because hardwoods require more maintenance, wider spacings are appropriate. Wider spacing allows landowners to put up tree shelters (if needed) and mow or spray around each tree. If cost-share funding is being used, the spacing should match the specifications in the cost-share agreement.

The following species can be managed in a way that allows desirable trees to grow back naturally.

Oak—The preferred reestablishment option for oaks is natural regeneration. Oak can be regenerated after the forest has advanced regeneration in the understory. Advanced regeneration seedlings are taller than 4 feet—these usually grow after a disturbance such as a fire or a harvest that removes some of the understory (in either upland or bottomland hardwood forests). Oak forests can be managed for longer-term rotations (70 to 150 years).

Medium- and poor-quality stands (Site Index*: 65–75): Oak will need to be cut in a shelterwood or expanding gap system combined with either herbicides or burning to control competing hardwoods prior to a final harvest.

High-quality stands (Site Index*: greater than 75): Sites should not be managed solely for oak because many other species such as yellow-poplar will outcompete it. Oak can remain a component of the stand but should not be the primary species grown.

*The site index value indicates how well trees will grow in a given soil type. Site index is the expected height that a tree will reach at a certain age (in this case, 50 years), assuming the trees are free to grow.

Yellow-poplar—The preferred option for management of yellow-poplar is through natural regeneration. The primary regeneration method is via a final, clearcut harvest. Yellow-poplar regenerates very quickly in medium- to high-quality soil types with site indexes greater than 65 (the height that the tree is expected to reach in 50 years). Selective harvesting or thinning is possible, though there is a risk of damaging the remaining trees. Most sites throughout the natural range of yellow-poplar in North Carolina have yellow-poplar seeds present in the soil; these will quickly germinate and grow after a clearcut harvest.

Depending on the site and the surrounding vegetation, species that can compete with yellow-poplar on high-quality sites can include sweetgum, red maple, and pine. Yellow-poplar can grow both in a near monoculture and as part of a diverse forest.

Cypress, water tupelo, and Atlantic white cedar—These trees are primarily regenerated through seed. To regenerate from seed, water tupelo and cypress (both bald cypress and pond cypress) swamps and Atlantic white cedar forests require favorable moisture conditions after harvesting and a seed source upstream (for cypress) or close by (for Atlantic white cedar). Usually site-prep herbicide spraying is required to prevent competing vegetation from taking over the desirable seedlings.

The successful regeneration of swamp systems primarily depends on the site hydrology. Changes in hydrology can prevent cypress, tupelo and Atlantic white cedar from regenerating. Hydrology can change dramatically based on a number of human-caused factors, including nearby clearing, development, road construction, ditching, or any other practice that physically alters the local watershed. Other threats to cypress swamps include salt intrusion from the rising ocean and flooding from beaver dams. Cypress-tupelo and Atlantic white cedar forest systems are highly sensitive to water salinity, so a small increase in salt can lead to the whole forest dying. Beaver dams will flood an area year-round, preventing seedlings from establishing.

Pine—Natural regeneration of pine (especially loblolly) is possible but not always preferred. Pine stands can be regenerated naturally from pine cones from the previous stand. Though natural regeneration is initially cheaper in loblolly pine, the seedling quality will be lower than a planted stand, growing slower and with poorer form and higher risk of fusiform rust. With natural regeneration, thinning is often required when the trees are about 5 years old. If pine stands are allowed to become overpopulated, trees may exhibit stagnant growth and be susceptible to pine beetle damage. The harvest methods for regenerating a pine stand naturally can include seed-tree, shelterwood, or clearcut.

Diverse longleaf ecosystems are often naturally regenerated via a shelterwood harvest and burning to kill competing hardwoods. Naturally regenerating a longleaf system can protect desirable diverse grasses and forbs that would be killed by herbicides. Burning eliminates hardwood competition and removes the leaf litter to allow native plants to regenerate.

Management in bottomland areas can be severely limited, depending on the time of year. Typically, harvesting in bottomland areas is not recommended in winter, when the groundwater table is highest. At this time of year, there is potential for heavy equipment to easily compact the soil along skid rows (where the skidder pulls felled logs to the log deck). This leaves large ruts in the ground or compacted tire tracks filled with standing water.

Rutting from heavy machinery compacts the ground, damaging the root systems of trees and leading to higher mortality of unharvested trees. Tree roots have difficulty expanding in compacted areas due to the lack of oxygen in the top 6 to 12 inches of soil. Compaction hurts standing trees and will hinder the growth of new seedlings that are planted or regenerated from seed.

Rutting also creates issues with equipment during future harvests. Harvesting equipment such as feller bunchers and skidders have difficulty operating on very uneven ground, reducing the number of potential future buyers who will want to work on the property. To partially fix rutting usually requires breaking up the compacted ground with a ripper prior to planting pine.

The best time to harvest bottomland sites is late spring through early fall, when the ground is relatively dry and trees are actively growing. The dry ground holds heavy harvesting equipment, preventing significant rutting. Other ways to prevent rutting can include using low ground pressure tire equipment and shovel logging when needed. Shovel logging involves using fallen trees to stabilize the ground over which logging equipment drives (along the skid rows). The logs that have been run over are picked up when the rest of the logging is complete.

Although rutting is not a large concern in upland areas, careful harvesting is required near streams and steep areas to prevent soil erosion. Follow harvesting best management practices to ensure that adequate buffers are preserved alongside streams to protect water quality.

¹ Native Region: M=Mountains, P=Piedmont, C=Coastal Plain ↲

² Light Requirements: S=Shade, P=Partial Sun, F=Full Sun ↲

³ Moisture Requirements: L=Low Moisture, M=Moderate Moisture, H=High Moisture, A=Aquatic ↲

Adapted from Guidelines for Riparian Buffer Restoration, Ecosystem Enhancement Program, N.C. Department of Environment and Natural Resources.