Basal area
Encyclopedia
Basal area is the term used in forest management
that defines the cross-sectional area of a tree at DBH, inside the bark.
In most countries, this is usually a measurement taken at a specimen's breast height
(1.3m or 4.5ft) above the ground and includes the entire diameter of every tree, including the bark. Measurements are usually made for 1 hectare
of land for comparison purposes to examine a forest's productivity and growth rate.
To estimate a tree's basal area, use the tree's diameter at breast height (DBH inside the bark) in inches with the following formula:
Basal Area = (3.1416 x (DBH/2)2)/(144)
(Note: The 144 is there to convert from Sq Inches to Sq Feet)
This formula simplifies to:
Basal Area = 0.005454 x DBH2
The result will be in ft2.
For the DBH in cm use:
Basal Area = 0.00007854 x dbh2
The result will be in m2.
The basal area of a forest stand can be found be adding the basal areas (as calculated above) of all of the trees in an area and dividing by the area of land in which the trees were measured. Basal area is generally expressed as ft2/acre or m2/ha.
A wedge prism
can be used to quickly estimate the basal area per hectare. To find your Basal Area using this method, simply multiply your BAF (Basal Area Factor) by the number of "in" trees in your variable radius plot. The BAF will vary based on the prism used, common BAF's include 5/8/10, and all "in" trees are those trees, when viewed through your prism from plot centre, that appear to be in-line with the standing tree on the outside of the prism.
Forest management
200px|thumb|right|[[Sustainable development|Sustainable]] forest management carried out by [[Complejo Forestal y Maderero Panguipulli|Complejo Panguipulli]] has contributed to the preservation of the forested landscape around [[Neltume]], a sawmill town in Chile...
that defines the cross-sectional area of a tree at DBH, inside the bark.
In most countries, this is usually a measurement taken at a specimen's 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....
(1.3m or 4.5ft) above the ground and includes the entire diameter of every tree, including the bark. Measurements are usually made for 1 hectare
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
of land for comparison purposes to examine a forest's productivity and growth rate.
To estimate a tree's basal area, use the tree's diameter at breast height (DBH inside the bark) in inches with the following formula:
Basal Area = (3.1416 x (DBH/2)2)/(144)
(Note: The 144 is there to convert from Sq Inches to Sq Feet)
This formula simplifies to:
Basal Area = 0.005454 x DBH2
The result will be in ft2.
For the DBH in cm use:
Basal Area = 0.00007854 x dbh2
The result will be in m2.
The basal area of a forest stand can be found be adding the basal areas (as calculated above) of all of the trees in an area and dividing by the area of land in which the trees were measured. Basal area is generally expressed as ft2/acre or m2/ha.
A wedge prism
Wedge prism
The wedge prism is a prism with a shallow angle between its input and output surfaces. Refraction at the surfaces causes the prism to deflect light by a fixed angle...
can be used to quickly estimate the basal area per hectare. To find your Basal Area using this method, simply multiply your BAF (Basal Area Factor) by the number of "in" trees in your variable radius plot. The BAF will vary based on the prism used, common BAF's include 5/8/10, and all "in" trees are those trees, when viewed through your prism from plot centre, that appear to be in-line with the standing tree on the outside of the prism.