The merchantable volume of timber on a hectare of forest increases with the age of the stand, as shown in the following table. Assume that all timber has a value of $5 per cubic meter, that the applicable interest rate is 6%, and that clearcut is the best management option (10%). Assume that initial stand establishment costs were $100/ha. Stand age (years) Timber volume (m3/ha)

25 300

30 420

35 500

40 640