Optimal fire management for maintaining community diversity

Disturbance events strongly influence the dynamics of plant and animal popu lations within nature reserves. Although many models predict the patterns o f succession following a disturbance event, it is often unclear how these m odels can be used to help make management decisions about disturbances. In this paper we consider the problem of managing fire in Ngarkat Conservation Park (CP), South Australia, Australia. We present a mathematical model of community succession following a fire disturbance event. Ngarkat CP is, a k ey habitat for several nationally rare and threatened species of birds, and because these species prefer different successional communities, we assume that the primary management objective is to maintain community diversity w ithin the park. More specifically, the aim of management is to keep at leas t a certain fraction of the park, (e.g., 20%), in each of three successiona l stages. We assume that each year a manager may do one of the following: l et wildfires burn unhindered, fight wildfires, or perform controlled burns. We apply stochastic dynamic programming to identify which of these three s trategies is optimal, i.e., the one most likely to promote community divers ity. Model results indicate that the optimal management strategy depends on the current state of the park, the cost associated with each strategy, and the time frame over which the manager has set his/her goal.