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
A Biomass and Bioenergy
Glossary for Forest Landowners
This publication defines unique biomass and bioenergy terms as they
relate to forestry and forest management. These definitions will help
you understand commonly used words and phrases that arise in
biomass and bioenergy literature and discussions.
A
Acre — An area of land
measuring 43,560 square feet.
Adaptive Management — A
dynamic approach to forest
management in which the
effects of treatments and
decisions are continually
monitored and used, along with
research results, to modify
management on a continuing
basis to ensure that objectives
are being met.
Anaerobic Digestion —
Decomposition of biological
wastes by micro-organisms,
usually under wet conditions, in
the absence of oxygen, to
produce a gas comprising
mostly methane and carbon
dioxide.
Annual Removals — The net
volume of growing stock trees
removed from the inventory
during a specified year by
harvesting, cultural operations
such as timber stand
improvement, or land clearing.
Ash — The noncombustible
components of fuel.
B
Barrel of Oil Equivalent
(BOE) — The amount of
energy contained in a barrel of
crude oil, i.e. approximately 6.1
GJ (5.8 million Btu), equivalent
to 1,700 kWh. A "petroleum
barrel" is a liquid measure equal
to 42 U.S. gallons (35 Imperial
gallons or 159 liters); about 7.2
barrels are equivalent to one
metric ton of oil.
Basal Area — (a) The cross-sectional
area (in square feet) of
a tree trunk at 4.5 feet above the
ground (Basal area of a tree is
0.005454 x diameter (inches)2).
(b) The sum basal areas of the
individual trees within 1 acre of
forest. For example a well-stocked
pine forest may have a
basal area of 80 to 120 square
feet per acre.
Best Management Practices
— Management practices that
maintain and improve the
environmental values of forests
associated with soils, water, and
biological diversity; primarily
used for the protection of water
quality.
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Bio-based Products — A commercial or
industrial product, other than food or feed,
that is composed in whole or in significant
part, of biological products or renewable
domestic agricultural materials including
plant, animal, marine materials, or forestry
materials. (US Department of Agriculture
designation)
Biochar — A type of charcoal produced
from biomass via pyrolysis. Often used as
a soil amendment.
Biochemical Conversion — The use of
fermentation or anaerobic digestion to
produce fuels and chemicals from organic
sources.
Biodiesel — A form of fuel for use in
diesel engines that is produced through a
chemical process called transesterfication
whereby glycerin is separated from
organically derived oils and fats.
Biodiversity — The variety of life forms in
a given area. Diversity can be
categorized in terms of the number of
species, the variety in the area’s plant and
animal communities, the genetic variability
of the animals, or a combination of these
elements.
Bioenergy — Renewable energy produced
from organic matter through the conversion
of complex carbohydrates. This energy may
either be used
directly as fuel, processed into liquids or
gasses, or be a residual of the processing or
conversion mechanisms.
Biofuels — Liquid, solid, or gaseous fuels
made from biomass resources, or their
processing and conversion derivatives.
Examples include biodiesel from vegetable
oil, bioethanol from sugar cane or wood
chips, and biogas from anaerobic
decomposition of wastes.
Biomass — Biomass is any organic matter
including forest and mill residues,
agricultural crops and wastes, wood and
wood wastes, animal wastes, livestock
operation residues, aquatic plants, and
municipal and industrial wastes.
Biorefinery — A facility that processes
and converts biomass into value-added
products. These products include
biomaterials, fuels (ethanol), or important
feedstocks for the production of chemicals
and other materials. Biorefineries can be
based on a number of processing platforms
using mechanical, thermal, chemical, and
biochemical processes.
Black Liquor — Solution of lignin-residue
and the pulping chemicals used to extract
lignin during the manufacture of paper.
Bottom Ash — Ash that collects under the
grates of a combustion furnace.
British Thermal Unit — A non-metric
unit of heat, still widely used by engineers.
One Btu is the heat energy needed to raise
the temperature of one pound of water from
60°F to 61°F at one atmosphere pressure. 1
Btu = 1055 joules (1.055 kJ).
Bundlers — A machine that collects,
compresses, and binds forest residues in to
bundles.
C
Calorific Value — The maximum amount
of energy that is available from burning a
substance. See Higher Heating Value.
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Cant — The remaining square section of a
log when rounded edges and bark are
removed.
Carbon Cycle — The distribution and
transfer of carbon through the Earth’s
ecosystem that includes such processes as
photosynthesis, decomposition, and
respiration.
Carbon Dioxide (CO2) — A colorless,
odorless, incombustible gas formed during
respiration, combustion of fossil fuels, and
organic decomposition.
Carbon Displacement — Offsetting of
carbon dioxide emissions from fossil fuel
combustion by substituting fossil fuels with
bioenergy.
Carbon Sequestration — The long-term
storage of carbon in the terrestrial
biosphere, underground, or oceans to
reduce the buildup of atmospheric carbon
dioxide concentrations.
Cellulose — A carbohydrate that is the
principal component of the cell secondary
walls of trees and other higher-order plants.
It occurs with other components such as
lignin’s, hemicellulose, waxes, and gums to
form long, hollow fibers.
Char — See Biochar.
Chip-n-saw — A cutting method used in
cutting lumber from trees that measure
between 6 and 14 inches diameter at breast
height. The process chips off the rounded
outer layer of a log before sawing the
remaining cant or rectangular inside section
into lumber. Chip-n-saw mills provide a
market for trees larger than pulpwood and
smaller than sawtimber.
Chipper — A large mechanized device that
reduces logs, whole trees, slab wood, or
lumber to chips of more or less uniform
size. Stationary chippers are used in
sawmills, while trailer-mounted whole-tree
chippers are used in the woods.
Chips — Woody material cut into short,
thin wafers. Chips are used as raw material
for production of paper, fiberboard,
biomass fuel, and other products.
Chip Van —Enclosed box trailers,
generally 8 to 8.5 ft in width, designed to be
less than 12.50 ft high when pulled by a
road tractor. The difference between the
box trailers seen on most highways and
vans hauling harvesting products (bulk
vans) is that most box trailers are built for
containerized cargo (commodities in boxes
or on pallets).
Clean Chips — Chipped wood free of
bark, needles, leaves, and soil
contamination.
Cleaning — Release treatment made in
forest stand not past the sapling stage to
free the favored trees from less desirable
vegetation that currently or soon will
overtop them.
Clearcutting — Regeneration or
harvesting method that removes essentially
all woody vegetation that would otherwise
compete with future crop trees in a single
harvesting operation.
Cofiring — Utilization of bioenergy
feedstocks to supplement energy source in
high efficiency boilers, usually with coal.
Cogeneration — The sequential
production of electricity and useful heat
energy from a common fuel source. Heat
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from this industrial process can be used to
power an electric generator, used for
industrial processes, or space and water
heating purposes.
Combustion — Burning. The
transformation of biomass fuel into heat,
chemicals, and gases through chemical
combination of hydrogen and carbon in the
fuel with oxygen in the air.
Combustion Efficiency — A measure of
the productive capture of chemical energy
in the fuel to heat energy, often expressed
as a percentage or ratio.
Comminuted Material — Biomass
material that has been pulverized or
precision reduced into smaller sized
material.
Container Trailer — A trailer designed to
hold bulk material. Built to be sturdy and
abused, they can be left on a site and filled
as desired, and then removed and replaced
with an empty container.
Cord — A stack of round or split wood
consisting of 128 cubic feet f wood, bark,
and airspace. A standard cord measures 4
feet by 4 feet by 8 feet. One cord weighs
approximately 2.68 tons for pine and 2.90
tons for hardwoods.
Course Woody Debris — Any piece(s) of
dead woody material (includes trunks,
branches, and roots) on the ground in forest
stands or streams with the large end
diameter often greater than 5 inches.
Crop Tree — Any tree selected to grow to
final harvest or to a selected size. Crop trees
are selected for quality, species, size, timber
potential, or wildlife value.
Crown Thinning — Removal of trees from
the upper level in the canopy in order to
favor desired crop trees whose crowns are
at a lower position in the canopy.
Cull — A tree or log of marketable size
that is rejected because it does not meet
certain specifications of usability or grade
because of species type or defects. Defects
can include crookedness, decay, injuries, or
damage from disease or insects.
Cut-to-Length — A harvest system in
which trees are felled, delimbed, and cut to
various log lengths at the stump.
D
Deadwood — Dead, standing or fallen,
woody biomass from trees or shrubs.
Deadwood can be the results of old age,
fire, disease, logging, and natural disasters.
Deck — A pile of logs on a landing. See
Landing.
Digester — An airtight vessel or enclosure
in which bacteria decomposes biomass in
water to produce gas. Also a chemical
process for pulping operations.
Dirty Chips — Chipped wood containing
bark, needles, leaves, and soil.
Down Woody Debris — Any piece(s) of
dead woody material (includes trunks,
branches, and roots) on the ground in forest
stands or streams. The woody debris can be
categorized as course woody debris or fine
woody debris based on its large-end
diameter.
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E
Ecology — The science or study of the
relationships between organisms and their
environment.
Ecosystem Services — Benefits people
obtain from ecosystems. These include
provisioning services such as food, water,
timber, and fiber; regulating services that
affect climate, floods, disease, wastes, and
water quality; cultural services that provide
recreational, aesthetic, and spiritual
benefits; and supporting services such as
soil formation, photosynthesis, and nutrient
cycling.
Effluent — The liquid or gas discharged
from a process or chemical reactor, usually
containing residues from that process.
Energy Crops — Crops grown specifically
for their fuel value. Crops can include
corn, sugarcane, switchgrass, and trees.
Energy Ratio — The ratio of the energy
output versus the energy input. The energy
ratio of a bioenergy process can be
calculated and compared to a conventional
fuel lifecycle. An energy ratio below one
suggests energy input is greater than energy
yield.
Environment — The interaction of
climate, soil, topography, and other plants
and animals in any given area. An
organism’s environment influences its
form, behavior, and survival.
Even-aged Management — Management
technique for a stand of trees composed of a
single age class.
F
Feedstock — Raw material used for the
generation of bioenergy and the creation of
other bioproducts.
Feller-buncher — A self-propelled
machine that cuts trees with saw or shears
near ground level and then stacks the trees
in piles to await transport (skidding).
Fermentation — Conversion of carbon-containing
compounds by micro-organisms
for production of fuels and chemicals such
as alcohols, acids or energy-rich gases.
Fine Woody Debris — Any piece(s) of
dead woody material (includes trunks,
branches, and roots) on the ground in forest
stands or streams with the large end less
than 5 inches in diameter.
Flail Delimber — A machine used for
delimbing tree stems. Flails are mounted
on spinning drums that mechanically beat
the limbs from the tree stem.
Fly Ash — Ash transported through the
combustion chamber by the exhaust gases
and generally deposited in the boiler heat
exchanger.
FOB — An acronym for free on board,
indicating that the price quoted includes
loading on or in the specified container.
Foliage — trees and other plant leaves,
considered as a group.
Forest Health — A measure of the vigor of
forest ecosystems. Forest health includes
biological diversity; soil, air, and water
productivity; natural disturbances; and the
capacity of the forest to provide a sustained
flow of goods and services for people.
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Forest Type — Groups of tree species
commonly growing in association because
of similar environmental requirements.
Examples include pine and mixed
hardwood; cypress, tupelo, and black gum;
and oak and hickory.
Forest Residue — Tops, limbs, bark,
foliage, and other woody materials, left
after a harvest.
Forwarder — A vehicle that carries logs
completely off the ground from stump to
road side landing.
Fossil Fuel — Solid, liquid, or gaseous
fuels formed over million of years from
plant and animal residues under high
temperature and pressure. Oil, natural gas,
and coal are fossil fuels.
Fuel Cell — A device that converts the
energy of a fuel directly to electricity and
heat, without combustion.
Fuel Treatment Thinnings — The process
of harvesting trees and underbrush from the
forest to reduce the risk of wildfires.
Full Cost Method — Cost accounting
method that allocates the total production
cost across biomass and conventional wood
products.
Furnace — An enclosed chamber or
container used to burn biomass in a
controlled manner to produce heat for space
or process heating.
G
Gas Turbine — A turbine that converts the
energy of hot compressed gases, produced
by burning fuel in compressed air into
mechanical power. Often fired by natural
gas or fuel oil.
Gasification — A chemical or heat process
to convert a solid fuel to a gaseous form.
Gasifier — A device for converting solid
fuel into gaseous fuel.
Gigawatt — A measure of electrical power
equal to one billion watts or 1,000,000
kilowatts. A large coal or nuclear power
station typically has a capacity of about 1
GW.
Glucose — A six-carbon fermentable sugar
(C6H12O6)
Grade — Utilization and established
quality or use classification of lumber,
trees, or other forest products.
Green Ton — 2000 lbs of undried
biomass. Moisture content must be
specified if green tons are used as a
measure of fuel energy.
Greenhouse Gas — A gas that absorbs
radiant energy from the earth, re-emitting it
as infrared radiation, contributing to the
warming of the earth. Examples of
greenhouse gases include carbon dioxide
and water vapor.
Grid — An electric utility company’s
system for distributing power.
Grinder — A machine that reduce particles
in size by repeatedly pounding them into
smaller pieces through a combination of
tensile, shear and compressive forces.
Group Selection — Is an uneven-aged
regeneration method used for sun loving
tree species in which trees are removed and
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new age classes are established in groups.
The width of a group is approximately
twice the height of mature trees.
H
Habitat — The place or environment
where a plant or animal naturally or
normally lives, grows and reproduces.
Heat Rate — The amount of fuel energy
required by a power plant to produce one
kilowatt-hour of electrical output. A
measure of generating station thermal
efficiency, generally expressed in Btu per
net kWh. It is computed by dividing the
total Btu content of fuel burned for electric
generation by the resulting net kWh
generation.
Hemicellulose — A polysaccharide
(complex carbohydrate) found in plant cells
that is easily extracted by dilute alkalies.
High Grading — A harvesting technique
that removes only the biggest and most
valuable trees from a stand and provides
high returns at the expense of future growth
potential. Poor quality, shade-loving trees
tend to regenerate and dominate high-graded
sites.
Higher Heating Value — The maximum
potential energy in bone-dry fuel. For
wood, the range is from 7,600 to 9,600
Btu/lb.
Hog Fuel — Wood and wood waste
biomass processed by grinding for use in a
combustor.
Hydrocarbon Feedstock — Petroleum
(hydrocarbon) based substance used as a
raw material in an industrial process.
Examples of petrochemical feedstocks are
ethylene, propylene, butadiene, benzene,
toluene, xylene, and naphthalene.
Hydrolysis — A chemical reaction that
releases sugars from cellulose and
hemicellulose, which are normally linked
together in complex chains.
I
Improvement Cutting — An intermediate,
partial, harvest that removes less desirable
trees of any species to improve the form,
quality, health or wildlife potential of the
remaining trees. Usually occurs after the
sapling stage and before final harvest.
Incinerator — Any device used to burn
solid or liquid residues or wastes as a
method of disposal. In some incinerators
heat is recovered.
Inclined Grate — A type of furnace in
which fuel is gravity fed from the top part
of a grate in a continuous ribbon, passes
over the upper drying section where
moisture is removed, and descends into the
lower burning section. Ash is removed at
the lower part of the grate.
Independent Power Producer — A power
production facility that is not part of a
regulated utility.
Indirect Impacts — The inter-industry
effects of input-output analysis; the impacts
above and beyond the direct effects when
applied to Type I multipliers.
Indirect Liquefaction — Conversion of
biomass to a liquid fuel through a synthesis
gas intermediate step.
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Induced Impacts — The impacts of
household expenditures in input-output
analysis.
J
Joule — Metric unit of energy, equivalent
to the work done by a force of one Newton
applied over a distance of one meter. One
joule = 0.239 calories.
K
KG and Pile — A site preparation method
in which stumps are pushed up, sheared off,
or split apart by a specially designed blade
mounted on a bulldozer. Debris is then
piled or placed in long rows (windrows) so
that an area can be bedded or flat planted.
KG Blade — A bulldozer-mounted blade
used in forestry and land-clearing
operations. A single spike splits and shears
stumps at their base.
Kilowatt — A measure of electrical power
equal to 1,000 watts. 1 kW = 3412 Btu/hr.
Kilowatt Hour — A measure of energy
equivalent to the expenditure of one
kilowatt for one hour. For example, 1 kWh
will light a 100-watt light bulb for 10 hours.
L
Landing — A cleared working area in the
forest where trees and logs are transported
(skidded) to be sorted, processed, and
loaded on a truck. See Deck.
Liberation Cutting — Removal of poor
quality or un-merchantable trees to favor
the growth of desirable trees.
Lignin — Structural constituent of wood
and (to a lesser extent) other plant tissues,
which encrusts the cell walls and cements
the cells together.
Logging residues — The unused portions
of growing-stock and non-growing-stock
trees cut or killed by logging and left in the
woods.
Log Rule or Log Scale — A table that
estimates volume or product yield from
logs and trees, based on a diagram or
mathematical formula.
Log Trailer — A trailer designed to haul
trees, poles, or shortwood in racks. They
are lightweight and have high payload
capacities.
Low Thinning — Removal of smaller,
weaker, and most deformed trees whose
crowns are in the lower portion of the stand
canopy.
Lump Sum Sale — A timber sale in which
the buyer and seller agree on a total price
for the standing timber. The standing
timber is either marked or is in a delineated
area.
M
Marginal Cost Method — Cost
accounting method that counts only the
additional costs from the conventional
logging operation as the biomass
production cost.
Marginal Land — Land that does not
consistently produce a profitable crop
because of infertility, drought, or other
physical limitations such as shallow soils.
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MBF — Abbreviation denoting 1,000
board feet. MBF is a typical unit of trade
for dimension lumber and sawtimber
stumpage.
Megawatt — (MW) A measure of electric
power equal to one million watts (1,000
kW)
Merchantable Height — The stem length,
measured from one foot above the ground
to a 10-, 6-, or 4-inch diameter top, above
which no other saleable product can be cut.
Diameter, local markets, limbs, knots, and
other defects collectively influence
merchantable height.
Mill/kWh — Tenths of a U.S. cent per
kilowatt hour. A common method of
pricing electricity in the United States.
Mill Residues — Excess material
generated from wood processing mills and
pulp and paper mills.
Mixed Stand — A timber stand containing
two or more prominent species in the main
canopy.
MMBtu — One million British thermal
units.
Moisture Content — The weight of the
water contained in wood, usually expressed
as a percentage of weight, either oven-dry
or as received (green).
Monoculture — The cultivation of a single
species crop.
N
Natural Stand — A stand of trees grown
from natural seed fall or sprouting.
Negotiated Sale — A timber sale in which
the buyer and seller negotiate a price for the
standing timber. The standing timber is
either marked or is in a delineated area.
Net Annual Growth — The average
annual net increase in the volume of trees
during the period between inventoies.
Nitrous Oxides (NOx) — A product of
photochemical reactions of nitric oxide in
ambient air, and the major component of
photochemical smog.
Nonindustrial Private Forest (NIPF) —
Forest land that is privately owned by
individuals or corporations other than forest
industry.
O
On the Stump — Standing, uncut timber.
One-pass Method — A harvest practice
where biomass and conventional
roundwood (sawlogs) are harvested and
recovered simultaneously.
Output — The value of production by
industry for a specific time period.
Oven Dry Ton — An amount of wood that
weighs 2,000 pounds at zero percent
moisture content.
Overstory — The portion of the trees
forming the uppermost canopy in a forest
stand.
Ozone — A compound that is formed when
oxygen and other compounds react in
sunlight. In the lower atmosphere (ground-level)
it is photochemical smog and is
considered a pollutant.
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P
Per-unit Sale — A timber sale in which the
buyer and seller negotiate a price per unit of
harvested wood, and the buyer pays for the
timber after it is cut and the volume is
determined.
Petrochemical Feedstock — Petroleum
(hydrocarbon) based substance used as a raw
material in an industrial process. Examples
of petrochemical feedstocks are ethylene,
propylene, butadiene, benzene, toluene,
xylene, and naphthalene.
Photosynthesis — A complex process that
occurs in the chlorophyll cells of plants to
build carbohydrates from carbon dioxide and
water, using energy derived from light.
Plantation — Planted pines or hardwoods,
typically in an ordered configuration such as
equally spaced rows.
Poles or Poletimber — Trees from 5 to 7
inches in diameter at breast height.
Pre-commercial Thinning — Thinning that
occurs when trees are too young, too small,
or of species undesirable to be used for
traditional timber products.
Process Heat — Heat used in an industrial
process rather than for space heating or other
power generation purposes.
Producer Gas — Fuel gas high in carbon
monoxide and hydrogen, produced by
gasifying a solid fuel with insufficient air or
by passing a mixture of air and steam
through a burning bed of solid fuel.
Pyrolysis — The thermal decomposition of
biomass at high temperatures (greater than
400° F, or 200° C) in the absence of air. The
end product is a mixture of solids (char),
liquids (oxygenated oils), and gases
(methane, carbon monoxide, and carbon
dioxide) with proportions determined by
operating temperature, pressure, and other
conditions.
Pulpwood — Wood used in the
manufacture of paper, fiberboard, or other
wood fiber products. Pulpwood- sized trees
are usually a minimum of 4 inches in
diameter.
Q
Quad — One quadrillion Btu (1015 Btu) =
1.055 exajoules (EJ), or approximately 172
million barrels of oil equivalent.
R
Reforestation — Reestablishing a forest by
planting or seeding an area from which
forest vegetation has been removed.
Regeneration Cut — A cutting strategy in
which old trees are removed while
favorable environmental conditions are
created for the establishment of a new stand
of seedlings.
Reproduction — (a) The process by which
young trees grow to become the older trees
of the future forest. (b) The process of
forest replacement or renewal through
natural sprouting or seeding or by the
planting of seedlings or direct seeding.
Residual Stand — Trees left in a stand to
grow until the next harvest. This term can
refer to crop trees or cull trees.
Residues, Biomass — Byproducts that
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have significant energy potential from
processing all forms of biomass.
Rotation — The number of years required
to establish and grow trees to a specified
size, product, or condition of maturity.
S
Salvage Cutting — Removal of trees that
have dead, damaged, or are expected to die,
generally as a result of natural disaster, pest
infestation, or disease infestation.
Sanitation Cut — Removal of dead and
weaker trees in an overstocked stand to
reduce the danger of natural disasters.
Seed-tree Harvest — A silvicultural
system in which all trees are harvested
except for a small number of selected trees
are retained for seed production for natural
regeneration.
Shelterwood Harvest — A silvicultural
system in which trees are removed in a
series of two or more cuts, leaving those
needed to produce sufficient shade to
produce a new forest in a moderated
microenvironment. This method produces
an even-aged forest.
Short-rotation Woody Crops — Fast
growing species, such as willows and
poplars, which are grown specifically for
the production of energy.
Shredder — A machine that tears material
apart by shearing.
Silviculture — Science and art of
managing the establishment, growth,
composition, and quality of forest stands
and woodlands for the desired needs and
values of landowners and society on a
sustainable basis.
Site Index — See Site Productivity.
Site Productivity — Combination of soil
and climatic factors contributing to plant
growth and development; may be measured
as biomass accumulation per unit of time.
Skidder — Machinery used to pull logs
from their stump to a landing. Logs are
pulled with a grapple, cable-winch, or
clam-bunk.
Slash — (a) Tree tops, branches, bark, or
other residue left on the ground after
logging or other forestry operations. (b)
Tree debris left after a natural catastrophe.
Softwood (conifer) — A tree belonging to
the order Coniferales. Softwood trees are
usually evergreen, bear cones, and have
needles or scale-like leaves.
Soil Fertility — The total availability,
concentration, and amount of essential plant
nutrients.
Soil Function — The role that soils play in
the environment and managed landscapes.
Soil Productivity — The capacity of a soil
to contribute to the production of a crop,
whether it is agricultural crops or forest
biomass.
Stand — A group of trees of similar age-class,
composition, and structure growing
on a site of uniform quality.
Stand Density — The number or mass of
trees occupying a site. Usually measured in
basal area or square feet per acre.
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Stocking — A description of the number of
trees, basal area, or volume per acre in a
forest stand compared with a desired level
for balanced health and growth. Most often
used in comparative expressions, such as
well-stocked, poorly stocked, or
overstocked.
Streamside Management Zones — Buffer
zones in which cover is retained in riparian
areas adjacent to surface water and aquatic
habitat.
Stumpage — The value or volume of a tree
or group of trees as they stand uncut in the
woods (on the stump).
Sustainability — The capacity of forests to
maintain their health, productivity,
diversity, and overall integrity, in the long
run, in the context of human activity and
use. Sustainability can apply to single
forest or ecoregions.
Sustainable Forest Management —
Forest management that ensures that forest
resources will be managed to supply goods
and services to meet the current demands of
society while conserving and renewing the
availability and quality of the resource for
future generations.
Sustained Yield — A forest management
strategy in which the net growth and yield
are balanced.
Syngas — A gas mixture that contains
varying amounts of carbon monoxide and
hydrogen generated by the gasification of a
carbon-based fuel to a gaseous product with
a heating value.
T
Thinning — A tree removal practice that
reduces tree density and competition among
remaining trees in a stand.
Timber Stand Improvement (TSI) —
Improving the quality of a forest stand by
removing or deadening undesirable species
to achieve desired stocking and species
composition. TSI practices include applying
herbicides, burning, girdling, or cutting.
Tolerant Species — A species of tree that
has the ability to grow in the shade of other
trees and in competition with them.
Transpiration Drying — The natural
drying that occurs when leafy biomass
material is left on the tree.
Tree-length — Trees felled, delimbed, and
topped in the stump area and processed at
the landing.
Two-pass Method — A harvest practice
where roundwood and biomass are
recovered in separate passes. Biomass
removal can precede or follow the
conventional product harvest.
U
Understory — (a) The layer formed by the
crowns of smaller trees in a forest. (b) The
trees beneath the forest canopy
Uneven-aged Management — A
regeneration and management technique
that removes some trees in all size classes
either singly, in small groups, or strips in
order to maintain a multi-aged stand.
Urban Residues — Wood and yard waste;
13
construction and demolition debris from an
urban source.
V
Value-added — Payments made by
industry to workers, interest, profits, and
indirect business taxes.
W
Water Quality — Suitability of the water
coming from ground and surface water
supplies for drinking water, recreational
uses, and as habitat for aquatic organisms
and other wildlife.
Water Quantity — Timing and total yield
of water from a watershed.
Watt — The common base unit of power in
the metric system. One watt = 3.413
Btu/hr.
Whole Tree Chips— Wood chips
produced by chipping whole trees, usually
in the forest. Thus the chips contain both
bark and wood.
Whole Tree Harvesting — Trees are felled
and transported to roadside with branches
and top intact. Processing occurs at the deck
or landing.
Wood Ash — Ash recovered from the
combustion of woody biomass; may be used
as fertilizer or soil liming agent to reduce
soil acidity.
Wood Processing Residue — The unused
portion of materials generated during wood
processing or by-products created during the
pulping process.
Woody Biomass — The trees and woody
plants, including limbs, tops, needles, leaves,
and other woody parts, grown in a forest,
woodland, or rangeland environment that are
the byproducts of proper forest management.
Y
Yarding — The initial movement of logs
from the point of felling to a central loading
area or landing, particularly by cable or
helicopter.
Yeast — Any of various single cell fungi
capable of fermenting carbohydrates
14
Definitions for this publication were compiled from
Megalos, M., and J. Kea. 2003. Understanding Forestry Terms. A Glossary for Private
Landowners. Woodland Owner Notes 26. Revised by R. Bardon. North Carolina
Cooperative Extension Service, Raleigh, NC. 11 p.
Rosillo-Calle, F., de Groot, P., Hemstock, S.L. and Woods, J. (eds) 2007. The Biomass
Assessment Handbook: Bioenergy for a Sustainable Environment. London: Earthscan. 269 p.
Glossary of Terms. Sustainable Forestry for Bioenergy and Bio-Based Products. Available
online [http://forestandrange.org/Biomass/Glossary/glossary.asp] Last visited March 10, 2008
Glossary of Terms. Woody Biomass Utilization. U.S. Department of Agriculture Forest
Service Available online [http://forestandrange.org/Biomass/Glossary/glossary.asp] Last
visited March 10, 2008
Feedstock Glossary. Energy Efficiency and Renewable Energy Biomass Program. U.S.
Department of Energy. Available online [http://www.fs.fed.us/woodybiomass/glossary.shtml]
Last visited March 21, 2008.
www.ces.ncsu.edu/forestry/biomass.html
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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.
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
Robert E. Bardon, PhD, Forestry Extension Specialist
WB-0001/2008