Articles on forestry topics include:.
The Mingo Oak was a white oak in the U.S. state of West Virginia. First recognized for its age and size in 1931, the Mingo Oak was the oldest and largest living white oak tree in the world until its death in 1938.
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.
The following outline is provided as an overview of and guide to forestry:
Basal area is the cross-sectional area of trees at breast height. It is a common way to describe stand density. In forest management, basal area usually refers to merchantable timber and is given on a per hectare or per acre basis. If you cut down all the merchantable trees on an acre at 4 ½ feet off the ground and measured the square inches on the top of each stump (πr*r), added them all together and divided by square feet, that would be the basal area on that acre. In forest ecology, basal area is used as a relatively easily-measured surrogate of total forest biomass and structural complexity, and change in basal area over time is an important indicator of forest recovery during succession .
Carl Alwin Schenck was a German forester and pioneering forestry educator. When Schenck came to the United States to work for George W. Vanderbilt at the Biltmore Estate, he became the third formally trained forester in the United States. He established and operated the Biltmore Forest School, the first forestry school in North America, on Vanderbilt's property.
A diameter tape (D-tape) is a measuring tape used to estimate the diameter of a cylinder object, typically the stem of a tree or pipe. A diameter tape has either metric or imperial measurements reduced by the value of π. This means the tape measures the diameter of the object. It is assumed that the cylinder object is a perfect circle. The diameter tape provides an approximation of diameter; most commonly used in dendrometry.
Tree allometry establishes quantitative relations between some key characteristic dimensions of trees and other properties. To the extent these statistical relations, established on the basis of detailed measurements on a small sample of typical trees, hold for other individuals, they permit extrapolations and estimations of a host of dendrometric quantities on the basis of a single measurements.
A Volume table is a chart to aid in the estimation of standing timber volume. These tables are based on volume equations and use correlations between certain aspects of a tree to estimate the volume to a degree of certainty. The diameter at breast height (DBH) and the merchantable height are used to determine the total volume. Difficulties occur when estimating the form class of the tree in question. The Mesavage and Girard form classes used to classify the trees to decide which volume table should be used. These volume tables are also based on different log rules such a Scribner, Doyle, and International ¼” scale. In order to be effective, the proper form class must be selected as well as accurate DBH and height measurements.
Forest inventory is the systematic collection of data and forest information for assessment or analysis. An estimate of the value and possible uses of timber is an important part of the broader information required to sustain ecosystems. When taking forest inventory the following are important things to measure and note: species, diameter at breast height (DBH), height, site quality, age, and defects. From the data collected one can calculate the number of trees per acre, the basal area, the volume of trees in an area, and the value of the timber. Inventories can be done for other reasons than just calculating the value. A forest can be cruised to visually assess timber and determine potential fire hazards and the risk of fire. The results of this type of inventory can be used in preventive actions and also awareness. Wildlife surveys can be undertaken in conjunction with timber inventory to determine the number and type of wildlife within a forest. The aim of the statistical forest inventory is to provide comprehensive information about the state and dynamics of forests for strategic and management planning. Merely looking at the forest for assessment is called taxation.
Girard form class is a form quotient calculated as the ratio of diameter inside bark at the top of the first 16 foot log to the diameter outside bark at breast height (DBH). Its purpose is to estimate board-foot volume of whole trees from measurement of DBH, estimation of the number of logs, and estimation of the taper of the first log, based on the general relationships identified between the taper of the first log and the taper of subsequent logs. Girard form class is the primary expression of tree form in the United States.
An angle gauge is a tool used by foresters to determine which trees to measure when using a variable radius plot design in forest inventory. Using this tool a forester can quickly measure the trees that are in or out of the plot. An angle gauge is similar to a wedge prism though it must be held a fixed distance from the eye to work properly. Unlike the wedge prism, which is held over the plot center, the surveyor's eye is kept over plot-center when using an angle gauge.
The wedge prism is a prism with a shallow angle between its input and output surfaces. This angle is usually 3 degrees or less. Refraction at the surfaces causes the prism to deflect light by a fixed angle. When viewing a scene through such a prism, objects will appear to be offset by an amount that varies with their distance from the prism.
The Biltmore Forest School was the first school of forestry in North America. Carl A. Schenck founded this school of "practical forestry" in 1896 on George W. Vanderbilt's Biltmore Estate near Asheville, North Carolina. The school grounds are now part of Pisgah National Forest in Transylvania County, North Carolina as the Cradle of Forestry in America, a 6500-acre historic site which features exhibits about forestry and forest conservation history.
In forestry, quadratic mean diameter or QMD is a measure of central tendency which is considered more appropriate than arithmetic mean for characterizing the group of trees which have been measured. For n trees, QMD is calculated using the quadratic mean formula:
Tree height is the vertical distance between the base of the tree and the tip of the highest branch on the tree, and is difficult to measure accurately. It is not the same as the length of the trunk. If a tree is leaning, the trunk length may be greater than the height of the tree. The base of the tree is where the projection of the pith (center) of the tree intersects the existing supporting surface upon which the tree is growing or where the seed sprouted. If the tree is growing on the side of a cliff, the base of the tree is at the point where the pith would intersect the cliff side. Roots extending down from that point would not add to the height of the tree. On a slope this base point is considered as halfway between the ground level at the upper and lower sides of the tree. Tree height can be measured in a number of ways with varying degrees of accuracy.
Tree girth is a measurement of the circumference of tree trunk. It is one of the most ancient, quickest, and simplest of foresters' measures of size and records of growth of living and standing trees. The methods and equipment have been standardized differently in different countries. A popular use of this measurement is to compare outstanding individual trees from different locations or of different species.
Tree volume is one of many parameters that are measured to document the size of individual trees. Tree volume measurements serve a variety of purposes, some economic, some scientific, and some for sporting competitions. Measurements may include just the volume of the trunk, or the volume of the trunk and the branches depending on the detail needed and the sophistication of the measurement methodology.
Trees have a wide variety of sizes and shapes and growth habits. Specimens may grow as individual trunks, multitrunk masses, coppices, clonal colonies, or even more exotic tree complexes. Most champion tree programs focus finding and measuring the largest single-trunk example of each species. There are three basic parameters commonly measured to characterize the size of a single trunk tree: tree height measurement, tree girth measurement, and tree crown measurement. Foresters also perform tree volume measurements. A detailed guideline to these basic measurements is provided in The Tree Measuring Guidelines of the Eastern Native Tree Society by Will Blozan.
A tree caliper is a special caliper to measure the diameter at breast height of a tree. When used in forestry, the term "caliper" can refer to the diameter of a tree's trunk at breast height itself. The measurement is generally made at 4.5 feet (1.4 m) to 5 feet (1.5 m) above the soil.
