Robustness of demographic estimates in studies of plant responses to fire

For demographic models of resprouting species in relation to fire regimes, spatially separated populations of different ages are usually treated as a chronosequence, and the average behaviour of these populations is used as the estimate of the generalized behaviour of a single population through time. Using the data of Bradstock (1990), we examine the way in which the between‐population variability affects the demographic parameters for Banksia serrata (Proteaceae) and thus assess whether the estimates of the shortest inter‐fire interval necessary to maintain a stable population size under low and high intensity fires are robust to variation in these parameters. The range of our estimates compares well to the average estimate of Bradstock (1990) for high intensity fires, but not for low intensity fires. However the relevant demographic parameters appear to vary more between populations than they do as a result of the length of the inter‐fire intervals, and the specific demographic model discussed here may have only local application.