Optimal Fire Management for Maintaining Community Diversity

Abstract

Disturbance events strongly influence the dynamics of plant and animal populations within nature reserves. Although many models predict the patterns of succession following a disturbance event, it is often unclear how these models 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 key 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 within the park. More specifically, the aim of management is to keep at least a certain fraction of the park, (e.g., 20%), in each of three successional stages. We assume that each year a manager may do one of the following: let wildfires burn unhindered, fight wildfires, or perform controlled burns. We apply stochastic dynamic programming to identify which of these three strategies is optimal, i.e., the one most likely to promote community diversity. 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.

The Diverse Impacts of Grazing, Fire and Weeds: How Ecological Theory Can Inform Conservation Management

“…Modelling optimal fire regimes (Richards et al 1999;Bradstock et al 2005) is a good example of the research direction that needs to be developed to enable landscape-scale management. Current examples show how it is possible to choose between competing fire management strategies for one species, taking dispersal into account (Bradstock et al 2005).…”

“…If successional responses are known, it may be possible to optimize fire management to maintain appropriate areas of each successional stage in the landscape (Richards et al 1999). Richards et al (1999) provide a model for choosing between competing management strategies such as suppressing fires or conducting fuel-reduction burns. Their model (and the later model of McCarthy et al 2001) did not consider temporal or spatial proximity of successional stages.…”

“…Their model (and the later model of McCarthy et al 2001) did not consider temporal or spatial proximity of successional stages. Proximity may be a critical issue for species that must disperse between areas at a suitable successional stage (Richards et al 1999), but currently we know very little about the capacity of species to disperse from unburnt to burnt patches.…”

Nature's Infinite Variety: Conservation Choice and Management for Dynamic Ecological Systems

“…To some extent, recent technological advances -notably in geographical information systems (GIS), modelling and remote sensing -have greatly aided this process (particularly such as for the maintenance of mosaic burning and representation of different seral stages across large conservation reserves: Richards et al 1999;Gill et al 2000). But conservation managers confront an increasingly formidable set of obstacles to orderly practice, and may be all too readily waylaid by short-term expediency or unpredicted events.…”

Tools for Conserving Managing Individual Plant Species in Dynamic Landscapes

“…For example, stochastic habitat models may be linked to population models to generate optimal decisions for landscape management (e.g. Richards et al 1999).…”