Frequently Used Forestry Terms
In order for a landowner to actively manage his/her woodlot, he/she must be able to communicate with his/her land manager. It is not uncommon for a land manager and a landowner to talk about the land management of a property and still not communicate. This is usually due to the lack of understanding of the terms used relating to forestry. On more than one occasion I have had conversations with clients concerning various aspects of their land and realized that while we were both using the same terms, we were talking about completely different things.
Forestry has it's own language, and in order for the landowner to properly understand the management of their land and make proper decisions, they need to understand this language. Below is a list of some of the common terms used in the forestry profession. This list does not include all of the terms (my glossary for a forest management plan contains 67 definitions), but only the ones that seem to be mentioned the most often in a forest management plan.
Acceptable Growing Stock (AGS): Stocking of trees which are currently or capable of producing #2 grade sawlogs and will have the ability to remain in the stand for the next 20 years.
Access: The ability to reach, enter, and move through a woodlot from a public road.
Basal Area: The area of the cross sections of trees 4 1/2 feet above the ground. Basal area per acre is used as a measure of stocking.
Board Foot: Unit of volume measurement equivalent to the volume of a board one foot long, one foot wide, and one inch thick.
Clearcut: The removal of all trees 2 inches DBH and greater from a designated area.
Cruise: A survey of forestland to locate timber and estimate it's quantity by species, size, and quality. A cruise is not a forest management plan but is an element of the forest management plan.
Cutting Cycle: The planned interval between operations in the same stand.
DBH: "Diameter at Breast Height" - tree diameter at 4.5 feet above the ground.
Defect: Internal rot, knots, or other problems in a live tree. The size and number of defects affects the "grade" of a log.
Grade: An evaluation method used by buyers to categorize the quality of the log. Different grades have different monetary values.
Hy-Grade: The removal of only the best trees from a stand. Taking the best and leaving the rest.
Landing: The location where the logs or trees from the stump are taken to be sorted and loaded on trucks for delivery.
Multiple Use: Concurrent use of the forest resources for more than one goal, i.e. timber production, wildlife habitat, watershed management, etc.
Palletwood: Grade of logs that are too rough, knotty, short, small, or crooked to be marketed as high quality sawlogs, but which are suitable to be sawn into railroad or landscape ties or pallet stock.
Poles: Trees measuring 4 to 10 inches DBH.
Pulpwood: Lower quality wood or trees suitable for use in industrial processes where wood is ground, chipped, or flaked to make paper, boards, or industrial fuel.
Saplings: Trees 2 to 4 inches DBH.
Sawlog: A log sufficient in size and quality to be suitable for sawing into lumber with conventional sawmill equipment.
Silviculture: The care and cultivation of a forest.
Site: The combined physical and biological qualities of an area of land which influences it's capacity for growing timber.
Stocking: The density of the stand of timber and the degree to which it occupies the growing resources of a site.
Stocking "A" Line: The stocking level at which the
stand is fully stocked. Stocking above the "A" line will
result in reduced growth and limited diameter expansion due to
competition. Stocking above the "A" line is considered
Stocking "B" Line: The stocking level at which a
stand will grow the fastest and occupy the most amount of growing space and
also maintain a desired form.
Stocking "C" Line: The stocking level at which the
stand is stocked at the minimum where a tree's form will be
maintained. Stands with stocking levels below the "C" line are
usually not worth trying to manage due to the difficulty of trying to maintain
Stumpage: The dollar value of standing timber. Usually used in the context of the value of the trees designated for harvest.
Timber Liquidation Value: The value of all standing trees in operable stands. Assumes a willing buyer and seller and that all merchantable timber will be harvested.
Timber Stand Improvement (TSI): Any method of improving young, small (0 to 8 inches DBH) stand of trees to increase growth, vigor, and quality. Generally non-commercial in nature.
Unacceptable Growing Stock (UGS): Stocking of trees that are not and will not have the capability of producing at least a #2 grade sawlog, or do not have the potential of remaining in the stand for the next 20 years.
Veneer Log: High quality log suitable for manufacturing wood veneers.