NC State Extension Publications

 

North Carolina has 17.7 million acres of commercial timberland, much of it owned by landowners like you. Although management goals vary across the landscape, most ownerships can benefit from a competitive market for low value, low quality brush and trees that may currently go unmanaged because of cost constraints. Producing energy, transportation fuels or other bio-based products from woody biomass is currently receiving much attention and scrutiny by business and policymakers. This note describes the types of forests and conditions that can be improved or restored by biomass harvesting. Similarly we identify forests non-suited for biomass harvest to help you determine the right management choice for your land and situation.

Why Woody Biomass

Woody biomass is a general term for low-quality trees unsuited to existing pulp or solid wood and sawtimber markets. Many businesses are hoping to capture woody biomass to power and the future economy with sustainable, renewable resources. Biomass’s relatively high harvest and transportation costs have precluded its use when oil was plentiful and inexpensive. Biomass usage for transportation fuel has been hampered by lack of technology and the high cost of building and operating the conversion facilities The drive toward energy independence, new markets and economic security has prompted a second look at wood as a viable energy source.

Analysis of North Carolina biomass availability in Table 1 (Hopkins and Hazel 2008) suggests a sustainable supply of some 4.7 million tons of biomass strictly from the residues of soft- and hardwood conventional harvests. Another 3 – 3.6 million tons/year may be available from the harvest of residual saplings or thinning operations. The unused woody biomass reserves nearly equal the available pulpwood that supplies the existing pulp and paper industry within North Carolina and its bordering states.


Table 1. North Carolina woody biomass availability (tons/year). Based on 1990-2002 harvest experience.
Logging Residues Residual Saplings Post-Thinning Residues Pulpwood Yields (for comparison) Total Residual Biomass
Softwood 1,557,979 462,109 392,358 3,831,581 2,412,446
Hardwood 3,142,689 2,587,764 216,247 4,850,434 5,946,722
Total 4,700,689 3,049,874 608,605 8,682,015 8,359,168

Is Biomass Harvesting Right For Your Situation?

A well-planned biomass harvest can benefit management objectives for open stands for recreation, forest health and wildfire risk reduction. Biomass harvests that renovate and restore low- quality forests can provide immediate economic savings. A conservative estimate of the revenues that accrue from shortening timber rotations should meet and exceed annualized returns from traditional management.

Managing with Biomass Harvests

  • Restore or renovate a low-quality forest
  • Expedite growth of high quality timber

Potential Savings from Biomass Harvest

  • Site preparation costs - $65- 150/acre
  • Shorten rotation length -$19/acre/year for each year saved on average forest acreage

Biomass harvesting offers several distinct advantages to you ongoing forest management operations:

Direct Savings

  • Seedbed preparation / Scarification of soil for light seeded species
  • Reduced Site Preparation costs

Indirect Benefits

  • Removal of harvest residues and competing small diameter, low-value trees
  • Increased usage of low-value species
  • Promote seedling establishment
  • Rehabilitate degraded stands
  • Increase of stand vigor
  • Prevention of large, natural mortality losses
  • Enhance crop tree growth
  • Shortened rotation lengths
  • Reduced risk of insect, disease and wildfire loss
  • Improve access, aesthetics and regrowth for wildlife

Integrating Biomass With Current Management

Planned biomass harvests in the form of thinning, partial or complete harvests in the four major forest types can fulfill multiple forest management and resource benefits. Always seek professional assistance before harvest and follow applicable laws and employ best management practices to minimize water quality impacts. To assess whether biomass harvesting coupled with your current management activities match your current condition (left side of table) by forest type (in bold) with desired management benefits (right side of table). Note: in some areas with mature biomass markets - harverst operation already integrate biomass into pricing, such that all harvests are cleaner and efficiently utilize most residues that arrive on the logging deck.


Current Condition Potential Management Benefits
Natural Pine
Dense, small materials Improved understory for wildlife
Growth slowed from overcrowding - in need of commercial thinnning Increased growth rate
Increased forest health
Reduced wildfire risk
Pine Plantations
Young stands too small for conventional thinning Sale of low value materials, improved habitat for early successional species
Dense, overcrowded stands - in need of commercial thinning, uniform stands in need of openings for wildlife access and recreation Earlier thinning - ups economic return, shortened rotation, increased productivity
Final harvest Higher value product mix
Mixed Species
Undesirable species mix Favors commercial, aesthetic or wildife beneficial species
Excess understory, invasive or off-site species

Promote mast producers

Open understory to sunlight for wildlife

Fire hazard and ladder fuel build-up

Increaase browse for wildlife

Enhanced natural regeneration

Hardwood Stands
Low-quality / poor form

Increase desirable species

Increase of commerical crop trees

High-graded or poor growing stock

Restoration of preferred species

Renovation of stand

Improved regeneration

Diseased or overgrazed stands

Increase mast producers

Improved growth of residual trees


Harvesting biomass for bioenergy can be easily integrated into the management systems for natural or plantation pine, mixed-hardwood, and hardwood forests in North Carolina.

While the returns from removing biomass for bioenergy may be a neutral or slightly positive economic benefit – it can significantly enhance other resource benefits. Chief among them are reduced site preparation costs, ease of planting, reduced site preparation burning and herbicide use, and healthier stands.

A sound management plan and professional resource oversight are integral to sustainable biomass and biofeedstock harvesting for energy and other value-added products.

Authors

Extension Forestry Specialist
Forestry & Environmental Resources
Assistant Professor and Extension Specialist, Forest Economics
Forestry & Environmental Resources
Area Specialized Agent, Forestry

Publication date: Jan. 1, 2008

North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status or disability. In addition, the two Universities welcome all persons without regard to sexual orientation.

La universidad N.C. State University y la universidad N.C. A&T State University se comprometen a llevar a cabo acciones positivas para asegurar la igualdad de oportunidades independientemente de la raza, el color de la piel, el credo, el origen nacional, la religión, el sexo, la edad, la condición de veterano de guerra, o la discapacidad de la persona. Además, las dos universidades acogen a toda persona independientemente de su orientación sexual.

North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age, veteran status or disability. In addition, the two Universities welcome all persons without regard to sexual orientation.