What is mean annual increment (MAI)?

What is mean annual increment (MAI)?

• A. The maximum height reached.
• B. The current annual increment.
• C. The average increase in tree size up to the total age, MAI = Ya/a.
• D. The mean annual increment after harvest.

Answer: (C)

Mean annual increment shows the average growth per year from planting up to a given age. It is calculated as size at age a divided by the age a (MAI = Ya / a), so it reflects the total growth accumulated over the stand’s life to that point. This measure smooths year-to-year fluctuations and helps indicate how productive a stand is over time, which is useful for choosing rotation age. It differs from the latest yearly growth, which only captures the current year’s gain (the current annual increment). Height or other single-visit measurements aren’t MAI, and after harvest you’d effectively start a new calculation for the new stand age.

Mean annual increment shows the average growth per year from planting up to a given age. It is calculated as size at age a divided by the age a (MAI = Ya / a), so it reflects the total growth accumulated over the stand’s life to that point. This measure smooths year-to-year fluctuations and helps indicate how productive a stand is over time, which is useful for choosing rotation age. It differs from the latest yearly growth, which only captures the current year’s gain (the current annual increment). Height or other single-visit measurements aren’t MAI, and after harvest you’d effectively start a new calculation for the new stand age.