Evaluate Supply Potential Statistics

Estimates presented in the Evaluate Supply Potential part of the Timber Supply Analysis application are derived from Forest Inventory and Analysis (FIA), a U.S. Forest Service program conducted in partnership with state forestry agencies.  A brief description of the area, volume, weight, growth, and removal estimates generated in this application is provided here.

Timberland Area

Timberland is land 1) with at least 10 percent canopy cover by live trees of any size, including land that formerly had such tree cover and that will be naturally or artificially regenerated, 2) not withdrawn by statute or administrative regulation prohibiting the management for production of wood products, and 3) capable of growing at least 20 cubic feet per acre per year.

Forest type is based on species composition.  If softwoods predominate (50 percent stocking or more), the forest type is softwood; if softwoods comprise 25 to 49 percent, it is mixed; and if softwoods comprise less than 25 percent, it is hardwood. Nonstocked timberland currently has less than 10 percent cover but formerly met the definition of timberland and will be regenerated.

Volume – All Live

Volume is the net volume of wood in the central stem of a live sample tree 5.0 inches diameter at breast height or larger, from a 1-foot tall stump to a minimum 4-inch top diameter outside bark, or to where the central stem breaks into limbs all of which are less than 4.0 inches diameter outside bark. Rotten, missing, and form cull are not included.

Volume – Pulpwood

Pulpwood is softwoods with diameter at breast height from 5.0 to 8.9 inches and hardwoods with diameter from 5.0 to 10.9 inches.  Volume is net volume of wood in the central stem of live trees, from a 1-foot tall stump to a minimum 4-inch top diameter outside bark, or to where the central stem breaks into limbs all of which are less than 4.0 inches diameter outside bark. Rotten, missing, and form cull are not included.

Hardness refers to the general durability of the wood and is influenced by its resistance to cutting, scratching, denting, pressure, or wear.  Soft hardwoods include species such as sweetgum, red maple, and yellow-poplar.  Hard hardwoods include species such as all oaks and hickories, green ash, winged elm, and sugar maple.

Volume – Sawtimber

For softwood species, sawtimber-size trees have diameter at breast height of at least 9.0 inches.  For hardwood species, sawtimber-size trees have diameter at breast height of at least 11.0 inches.  Volume is the net board-foot volume (International ¼-inch rule) in the sawlog portion of commercial species containing at least a 12-foot sawlog or two non-contiguous sawlogs 8 feet or longer that meets regional specifications for defect.  Volume is measured from a 1-foot tall stump to a minimum top diameter or to where the top breaks into limbs all of which are less than the minimum top diameter. Minimum top diameter is 7.0 inches for softwoods and 9.0 inches for hardwoods.

Small softwood, also known as chip-n-saw, consists of trees 9.0 to 10.9 inches diameter at breast height.  Large softwood consists of trees at least 11.0 inches diameter at breast height.

Hardness refers to the general durability of the wood and is influenced by its resistance to cutting, scratching, denting, pressure, or wear.  Soft hardwoods include species such as sweetgum, red maple, and yellow-poplar and tend to be used for crates, pallets, upholstered furniture components, and light construction. Hard hardwoods include species such as all oaks and hickories, green ash, winged elm, and sugar maple and are used for flooring, furniture, cabinetry, veneer, interior trim, and doors.

Tree grade is determined by factors including tree size (diameter at breast height, length, and scaling diameter), grading faces, and tree defects.  Grade 1 trees are capable of producing a large proportion of wood that can be used for high-value wood products.  Grade 2 trees are capable of producing some high-value wood products, but not as much as Grade 1.  Grade 3 trees are capable of producing only a small proportion of high-value wood products.  A sawtimber-size tree is classified as “no grade” if it is not capable of producing enough high-quality wood products to rank as Grade 3.

Weight – All Live

Weight is the green weight of sound wood, including bark, in the merchantable bole of live trees 5.0 inches diameter at breast height or larger, from a 1-foot tall stump to a minimum 4-inch top diameter outside bark, or to where the central stem breaks into limbs all of which are less than 4.0 inches diameter outside bark.  Rotten, missing, and form cull are not included.

Weight – Pulpwood

Pulpwood is softwoods with diameter at breast height from 5.0 to 8.9 inches and hardwoods with diameter from 5.0 to 10.9 inches.  Weight is the green weight of sound wood, including bark, in the merchantable bole of live trees, from a 1-foot tall stump to a minimum 4-inch top diameter outside bark, or to where the central stem breaks into limbs all of which are less than 4.0 inches diameter outside bark.  Rotten, missing, and form cull are not included.

Hardness refers to the general durability of the wood and is influenced by its resistance to cutting, scratching, denting, pressure, or wear.  Soft hardwoods include species such as sweetgum, red maple, and yellow-poplar.  Hard hardwoods include species such as all oaks and hickories, green ash, winged elm, and sugar maple.

Weight – Sawtimber

For softwood species, sawtimber-size trees have diameter at breast height of at least 9.0 inches.  For hardwood species, sawtimber-size trees have diameter at breast height of at least 11.0 inches.  Weight is the green weight of sound wood, including bark, in the sawlog portion of commercial species containing at least a 12-foot sawlog or two non-contiguous sawlogs 8 feet or longer that meets regional specifications for defect.  Weight is measured from a 1-foot tall stump to a minimum top diameter or to where the top breaks into limbs all of which are less than the minimum top diameter.  Minimum top diameter is 7.0 inches for softwoods and 9.0 inches for hardwoods.

Small softwood, also known as chip-n-saw, consists of trees 9.0 to 10.9 inches diameter at breast height.  Large softwood consists of trees at least 11.0 inches diameter at breast height.

Hardness refers to the general durability of the wood and is influenced by its resistance to cutting, scratching, denting, pressure, or wear.  Soft hardwoods include species such as sweetgum, red maple, and yellow-poplar and tend to be used for crates, pallets, upholstered furniture components, and light construction.  Hard hardwoods include species such as all oaks and hickories, green ash, winged elm, and sugar maple and are used for flooring, furniture, cabinetry, veneer, interior trim, and doors.

Tree grade is determined by factors including tree size (diameter at breast height, length, and scaling diameter), grading faces, and tree defects.  Grade 1 trees are capable of producing a large proportion of wood that can be used for high-value wood products.  Grade 2 trees are capable of producing some high-value wood products, but not as much as Grade 1.  Grade 3 trees are capable of producing only a small proportion of high-value wood products.  A sawtimber-size tree is classified as “no grade” if it is not capable of producing enough high-quality wood products to rank as Grade 3.

Growth and Removals – All live

Growth estimates are average annual net growth of live trees at least 5 inches diameter at breast height on timberland.  Net growth estimates are gross growth minus mortality.  It is possible for net growth to be negative.  For example, net growth may be negative when mortality exceeds gross growth as may happen after a hurricane or other major disturbance.  Removal estimates are average annual removals of live trees at least 5 inches diameter at breast height on timberland.

Growth and Removals – Pulpwood

For softwoods, pulpwood includes trees 5.0 to 8.9 inches diameter at breast height.  For hardwoods, pulpwood includes trees 5.0 to 10.9 inches diameter at breast height.  Net growth estimates are gross growth minus mortality.  It is possible for net growth to be negative.  For example, net growth may be negative when mortality exceeds gross growth as may happen after a hurricane or other major disturbance.  Removal estimates are average annual removals of live, pulpwood-size trees on timberland.

Growth and Removals – Sawtimber

For softwoods, sawtimber trees are 9.0 inches and larger diameter at breast height.  For hardwoods, sawtimber trees are 11.0 inches and larger diameter at breast height.  Net growth estimates are gross growth minus mortality.  It is possible for net growth to be negative.  For example, net growth may be negative when mortality exceeds gross growth as may happen after a hurricane or other major disturbance.  Removal estimates are average annual removals of live, sawtimber-size trees on timberland.

About the Data

It should be emphasized that the quantities reported are an indication of what is potentially available.  Reported estimates do not account for future possible increased usage by existing industries, future new usage by industries either proposed or under construction, or the economics associated with the procurement of the timber.

Estimates presented in this application come from Forest Inventory and Analysis (FIA).  Estimates were generated from data in FIA Database (FIADB) downloaded from the FIA Datamart on 2 September 2020.  The naming convention for estimates is based on the latest year of data used to produce the estimate.  For example, estimates of volume presented as 2015 come from data collected, for the most part, from 2011 through 2015.

Estimates are based on a sample and are therefore subject to sampling error.  FIA is designed to provide reliable estimates over large areas (e.g., East Texas). In general, with more specific estimates (e.g., publicly-owned versus all ownerships, 50-mile supply radius versus 100-mile supply radius) sampling errors will increase and the reliability of the estimate will decrease.  Sampling errors should be considered in any application of the estimates presented in this application.

Growth and removals are estimated from remeasurement data — plots that have been measured at two points in time.  Estimates of net growth and removals are based on the current (i.e., time 2) ownership of those attributes if available, otherwise previous (i.e., time 1).  The accounting method, which accounts for shifts between classes during the remeasurement period, was used to estimate net growth by diameter class.  Removal estimates by diameter class are based on the midpoint temporal basis (diameter estimated at midpoint of remeasurement period).