Growth measured by PAI represents growth over what typical time span?

Growth measured by PAI represents growth over what typical time span?

• A. Five years
• B. Ten years
• C. Fifteen years
• D. Twenty years

Answer: (B)

PAI stands for periodic annual increment and represents the average annual growth over a defined interval between measurements. It is found by taking the total increase in a stand metric (like volume or basal area) during that interval and dividing by the number of years in the interval. In many forest inventories, measurements are taken at fixed intervals of about ten years, so growth reported as PAI typically spans ten years. For example, if volume goes from V1 to V2 over ten years, PAI = (V2 − V1) / 10. If the interval were five years, the PAI would reflect five-year growth, but the common practice of ten-year inventory intervals makes ten years the typical span for PAI.

PAI stands for periodic annual increment and represents the average annual growth over a defined interval between measurements. It is found by taking the total increase in a stand metric (like volume or basal area) during that interval and dividing by the number of years in the interval. In many forest inventories, measurements are taken at fixed intervals of about ten years, so growth reported as PAI typically spans ten years. For example, if volume goes from V1 to V2 over ten years, PAI = (V2 − V1) / 10. If the interval were five years, the PAI would reflect five-year growth, but the common practice of ten-year inventory intervals makes ten years the typical span for PAI.