Basal area is measured in what units?

Basal area is measured in what units?

• A. Square meters per hectare
• B. Square feet per acre
• C. Cubic feet per acre
• D. Linear feet per acre

Answer: (B)

Basal area is a measure of the cross-sectional area of all tree stems at breast height expressed per unit land area. Because it combines an area (the cross-section of stems) with a land area, the units are an area per area. In U.S. forestry practice this is square feet of stem cross-section per acre, which is why square feet per acre is the correct choice. (In metric terms, the equivalent is square meters per hectare.) The cross-sectional area for each tree is calculated from its diameter at breast height (DBH) using area = π(radius)^2, then summed across trees and divided by the land area to obtain basal area per acre. The other options describe volume or linear measurements, which do not represent basal area.

Basal area is a measure of the cross-sectional area of all tree stems at breast height expressed per unit land area. Because it combines an area (the cross-section of stems) with a land area, the units are an area per area. In U.S. forestry practice this is square feet of stem cross-section per acre, which is why square feet per acre is the correct choice. (In metric terms, the equivalent is square meters per hectare.) The cross-sectional area for each tree is calculated from its diameter at breast height (DBH) using area = π(radius)^2, then summed across trees and divided by the land area to obtain basal area per acre. The other options describe volume or linear measurements, which do not represent basal area.