Cutting trees: In forestry management it is important to know the net stumpage value of a stand (that is, a group) of trees. This is the commercial value of the trees minus the costs of felling,...

Cutting trees: In forestry management it is important to know the net stumpage value of a stand (that is, a group) of trees. This is the commercial value of the trees minus the costs of felling, hauling, etc. The graph in Figure 1.39 shows the net stumpage value V , in dollars per acre, of a Douglas fir stand in the Pacific Northwest as a function of the age t, in years, of the stand.24 a. Estimate the net stumpage value of a Douglas fir stand that is 60 years old. b. Estimate the age of a Douglas fir stand whose net stumpage value is $40,000 per acre. c. At what age does the commercial value of the stand equal the costs of felling, hauling, etc.? d. At what age is the net stumpage value increasing the fastest? e. This graph shows V only up to age t = 160 years, but the Douglas fir lives for hundreds of years. Draw a graph to represent what you expect for V over the life span of the tree. Explain your reasoning.