You are building a forest planning model, and have decided that the decision variables

$($xi$,$j$,$k$)$ will represent the area $($ha$)$ of forest established in period i that is scheduled for a

clearcut harvest in period j and then to be placed on a k period rotation. The first period

in the planning horizon will be labeled $1,$ the second $2,$ and so on$.$ Assume that

$$ the objective function maximizes discounted net revenue $($$$)$ over a ten$-$period

planning horizon,

$$ each of the periods is $10$ years long,

$$ all activities occur at the midpoint of a time period,

$$ the net revenue associated with timber harvest is $75$ $$/$m$3$

$,$

$$ the discount rate is $5\%,$ and

$$ existing and regenerated timber grows according to the yield table below.