Managing forests for biomass potential

              NC Woody Biomass
“Nature’s renewable energy!”
http://www.ces.ncsu.edu/fore
stry/biomass.html
Extension Forestry
Campus Box 8008
NC State University
Raleigh, NC 27695-8008
Table 1. NC 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 3,142,710 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
Managing Forests for Biomass Potential
NC has 17.7 million acres of commercial timberland, much of it owned by
landowners like you. Although management goals vary across the
landscape, all ownerships can benefit from a competitive market for low
value, low­quality
brush and trees that may currently go unmanaged
because of cost constraints. Producing energy and transportation fuels
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 by biomass harvesting to help you
determine if it is the right choice for your land and situation.
Why Woody Biomass?
Woody biomass is a general term for low-quality trees unsuited to
existing pulp and sawtimber markets. Many businesses are hoping to
capture woody biomass to power and fuel the future economy with
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 and economic security
has prompted a second look at wood as a viable energy source.
Recent analysis of N.C 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.
2
Is Biomass Harvesting Right for You?
A well-planned biomass harvest can benefit your management objectives for open stands for
recreation, forest health and wildfire risk reduction. Biomass harvests that renovate and
restore low quality forests 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 Potential Savings from Biomass
Harvest
Restore or renovate a low quality forest. Site Preparation Costs - $65- 150/acre
Expedite growth of high quality timber Shorten Rotation Length -$19/acre/yr
Harvesting biomass 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 and prevention of large, natural mortality losses
• Promote crop tree growth, shortened rotation lengths
• Reduced risk of insect, disease and wildfire loss
• Improve access, aesthetics and regrowth for wildlife
3
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).
Current Condition Potential Management Benefits
Natural Pine
Dense, small materials
Growth slowed from overcrowding-in
need of pre-commercial thinning
Improved understory for wildlife
Increased growth rate
Increased forest health
Reduced wildfire risk
Pine Plantations
Young stands too small for conventional
thinning
Dense, overcrowded stands - in need of
commercial thinning,
Uniform stands in need of openings for
wildlife, access and recreation
Final harvest
Sale of low value materials,
Improved habitat for early successional
species
Earlier thinning – ↑ economic return
Shortened rotation
Increased productivity
Higher value product mix
Mixed Species
Undesirable species mix
Excess understory, invasive or off-site
species
Fire hazard and ladder fuel build-up
Favor commercial species
Promote mast producers
Open understory to sunlight for wildlife
Browse or regeneration
Hardwood Stands
Low quality/ poor form
High graded or poor growing stock
Diseased or overgrazed stands
Increase of desirable species
Restored or renovated stand improved
regeneration
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.
www.ces.ncsu.edu/forestry/biomass.html
Published by North Carolina Cooperative Extension
Distributed in furtherance of the acts of Congress of May 8 and June 30, 1914. 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. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local
governments cooperating.
copies of this public document were printed at a cost of or per copy.
Prepared by
Mark Megalos, NCSU Extension Forestry
WB-0007/2008