Site tree (forestry)
Encyclopedia
Site tree refers to a type of tree used in forestry
to classify the quality of growing conditions at a particular forest location. A site tree is a single tree
in a stand (group of growing trees) that gives a good representation of the average dominant or co-dominant tree in the stand. Site trees are used to calculate the site index
of the site in reference to a particular tree species. A site tree should belong to the dominant or co-dominant overstory
class. The total height of the tree and age measured at Diameter at breast height
of a sample of site trees will be used to determine a site index
, which will show how tall trees of different species can grow on that site in a set amount of time. Sometimes several years are added to the breast-height age to account for time grown below 4.5 feet (1.4 m).
Determining what a site tree should look like in a stand varies with what kind of stand one is standing in. The simplest stand to find a site tree in is an even aged stand of a single species
, much like a forest
plantation
. In this stand almost any dominant or co-dominant tree can be used. Finding a site tree is more difficult in uneven-aged, mixed species, stands.
There are multiple assumptions that are made when a site tree is chosen. Each site tree is assumed to have been a dominant or co-dominant individual its entire life. The site tree is assumed to have never been broken, injured, or suppressed. If the tree had any of these things happen to it the site index, which is derived from the site tree, value will be skewed.
Site trees are chosen by what species is being grown in a particular forest. Different trees on the same site will produce different measurements of a site index. For example, a yellow-poplar (Liriodendron tulipifera
) growing on the same site as a white oak (Quercus alba) will grow at a different rate over the same amount of time. Graphs have been made that allow the user to measure a site tree of specific species and then use that measurement to predict what the measurements of a site tree of another species would be on the same site. This allows the user to predict how one species would grow on a site if that species was planted on the site. This is especially useful for timber
production, harvest operations, or any other forestry silvicultural
management that has specific species regeneration as a goal of the management plan.
Forestry
Forestry is the interdisciplinary profession embracing the science, art, and craft of creating, managing, using, and conserving forests and associated resources in a sustainable manner to meet desired goals, needs, and values for human benefit. Forestry is practiced in plantations and natural stands...
to classify the quality of growing conditions at a particular forest location. A site tree is a single tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
in a stand (group of growing trees) that gives a good representation of the average dominant or co-dominant tree in the stand. Site trees are used to calculate the site index
Site index
Site index is a term used in forestry to describe the potential for forest trees to grow at a particular location or "site." Site is defined as “inherent characteristics of the physical environment”; furthermore, the word site is used in forestry to refer to a distinct area where trees are found....
of the site in reference to a particular tree species. A site tree should belong to the dominant or co-dominant overstory
Canopy (forest)
In biology, the canopy is the aboveground portion of a plant community or crop, formed by plant crowns.For forests, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms .Sometimes the term canopy is used to refer to the extent...
class. The total height of the tree and age measured at Diameter at breast height
Diameter at breast height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements....
of a sample of site trees will be used to determine a site index
Site index
Site index is a term used in forestry to describe the potential for forest trees to grow at a particular location or "site." Site is defined as “inherent characteristics of the physical environment”; furthermore, the word site is used in forestry to refer to a distinct area where trees are found....
, which will show how tall trees of different species can grow on that site in a set amount of time. Sometimes several years are added to the breast-height age to account for time grown below 4.5 feet (1.4 m).
Determining what a site tree should look like in a stand varies with what kind of stand one is standing in. The simplest stand to find a site tree in is an even aged stand of a single species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, much like a forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
plantation
Plantation
A plantation is a long artificially established forest, farm or estate, where crops are grown for sale, often in distant markets rather than for local on-site consumption...
. In this stand almost any dominant or co-dominant tree can be used. Finding a site tree is more difficult in uneven-aged, mixed species, stands.
There are multiple assumptions that are made when a site tree is chosen. Each site tree is assumed to have been a dominant or co-dominant individual its entire life. The site tree is assumed to have never been broken, injured, or suppressed. If the tree had any of these things happen to it the site index, which is derived from the site tree, value will be skewed.
Site trees are chosen by what species is being grown in a particular forest. Different trees on the same site will produce different measurements of a site index. For example, a yellow-poplar (Liriodendron tulipifera
Liriodendron tulipifera
Liriodendron tulipifera, commonly known as the tulip tree, American tulip tree, tuliptree, tulip poplar or yellow poplar, is the Western Hemisphere representative of the two-species genus Liriodendron, and the tallest eastern hardwood...
) growing on the same site as a white oak (Quercus alba) will grow at a different rate over the same amount of time. Graphs have been made that allow the user to measure a site tree of specific species and then use that measurement to predict what the measurements of a site tree of another species would be on the same site. This allows the user to predict how one species would grow on a site if that species was planted on the site. This is especially useful for timber
Timber
Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
production, harvest operations, or any other forestry silvicultural
Silviculture
Silviculture is the practice of controlling the establishment, growth, composition, health, and quality of forests to meet diverse needs and values. The name comes from the Latin silvi- + culture...
management that has specific species regeneration as a goal of the management plan.