Estimation of fire frequency and fire cycle: a computational perspective

Abstract

This paper examines different concepts and methods of estimating fire frequency and fire cycle used in models of forest dynamics, from a computational perspective. Fire frequency and fire cycle can be defined in point-based and area-based ways, and the analytical results indicate that the different definitions are interrelated with each other, except the fire number-based fire frequency definition. The point-based definitions can be seen as special cases of area-based definitions when area is reduced to a single site. The generation of an ideal historical fire data set allowed a comparison among different methods of estimating fire frequency and fire cycle in terms of associated bias. An over-estimate of fire cycle could be generally expected by using stand-origin maps, and recent fire history could influence the estimate significantly. The number of fire maps required to obtain a relatively stable fire cycle estimate is also influenced by fire history. Point-based data obtained from random and systematic sampling designs displayed almost equally good fire cycle estimates for the tested data set, when the sample sizes relative to the total number of possible sample units are large.