When to harvest? The e ect of disease on optimal forest rotation

E ective forest management is crucial to maximising the economic bene ts obtained from forests. However, the arrival of novel pests and pathogens may have a negative e ect on timber values. We argue that management strategies should be calibrated to consider the e ect of disease and in this paper explore the optimal rotation length of a single rotation, even-aged, plantation forest under varying disease conditions. We show that the optimal rotation length, which maximises the net present value of the forest, is reduced when disease decreases the timber value. Moreover, an increase in the rate of disease progression or the e ect of disease on timber value has a negative e ect on the optimal rotation length. More generally, the e ect of forest disease on optimal management depends in a complex way on the interaction of economic, ecological and epidemiological parameters.