OBJECTIVE FORESTRY

Detailed explanation-1: -Basal area is the common term used to describe the average amount of an area (usually an acre) occupied by tree stems. It is defined as the total cross-sectional area of all stems in a stand measured at breast height, and expressed as per unit of land area (typically square feet per acre).

Detailed explanation-2: -Basal area is the cross-sectional area of trees at breast height (1.3m or 4.5 ft above ground). 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.

Detailed explanation-3: -BA is measured by adding the area of the stems at breast height of all the trees in the stand. Because of the time required to measure every tree, only a sample of the stand is measured. The sample is used to predict the total amount of basal area in the stand.

Detailed explanation-4: -Divide the diameter by 4 and then multiple by 100 to express the measurement in metres. For example, if the diameter of a tree is 60 cm, then d/4 = 15cm. To achieve the minimum basal area of 12 m2 /ha, another tree of the same diameter must be retained within 15 m from the measured tree (15 cm x 100 = 15 m).