Natural fire disturbances are known to have had a significant role in boreal forests at the stand and landscape levels. Van Wagner's exponential model gave useful insight into the theoretical dynamics of the forest age distribution in fire-disturbed landscapes. His work motivated extensions to the theoretical model and more empirical tests in a variety of landscapes. The empirical tests have had mixed results. While Van Wagner stated that the model is theoretical, and warned that one should expect to find variability in landscapes in any case, there is the risk that the exponential model can be misunderstood or inappropriately applied if variability is not adequately considered. An existing theoretical simulation model of landscape fire disturbance (FLAP-X) was used to explore the temporal variability of two selected landscape attributes: the percentages of old growth and recently disturbed area. It was found that under characteristic boreal fire disturbance regimes, these percentages can vary widely over time even at large spatial scales due to the spatiotemporal autocorrelation of disturbances. Some of the consequent implications of managing a landscape for naturalness at multiple spatial scales when there is a wide range of conditions that can be considered natural are discussed.