We extend the Pressler’s indicator rate formula under the generalized Reed model to account for the impacts of current and future stochastic disturbance risk on the current harvesting decision. We prove that that the mathematical framework of the Pressler’s indicator rate holds under the generalized Reed model. We apply it to the management of longleaf pine to determine the optimal harvest age under the risk of wildfires. We determine that the Pressler’s indicator rate formula provides a useful framework to determine the minimum timber salvage increment required to decide when to harvest longleaf pine under the risk of wildfire.