Use of prescribed burning for restoration and maintenance of ecological conditions: Predicting and managing fire injury and tree mortality

Managers and scientists often seek to use fire to restore and maintain historic or natural species composition, stand structure, wildlife habitat, landscape pattern and ecological functioning. Successful use of under-burning in forests and woodlands requires integration of fi re behavior and fire effects knowledge into the planning, implementation, and monitoring of restoration projects. Trees consist of three highly integrated organs: crown, roots, and stem or bole. These organs have differing physiological functions and morphological properties that are important considerations in prescribed burning. Fires burning in various vegetative fuel complexes, and under differing weather conditions, have typical energy release characteristics and associated temperature histories, which when integrated with plant attributes can be used to predict fire effects. Managers need guidelines on how to safely and effectively apply fire to meet desired restoration goals. These guidelines need to be based on knowledge of the interactions between fuel consumption, fire behavior and tree morphological characteristics that confer resistance to thermal injury. Likewise knowledge is needed on how burn injuries affect survival and growth. This paper reviews and synthesizes the biophysical processes controlling fire injury and the physiological responses to injury. Models of fuel consumption, fire behavior and heat transfer are integrated with data from field burning experiments from Eurasia and North America to illustrate fire injury mechanisms and physiological responses. Changes in fire resistance and resilience associated with species and age/morphology differences are discussed. The theoretical and empirical knowledge are integrated into guidelines for the effective planning, implementation, and monitoring of fire restoration projects