Using modeling software, we estimated the range of natural variation (RONV) of landscape structure within the Invermere TSA. We modelled fire disturbances and multi-layered stand dynamics for both the historic natural fire regimes (HNFR) and for current fire regimes, including forest harvesting. Two measures of landscape structure are reported: the age class or seral class profile, and the structural class profile. Age classes are based on the BC Ministry of Forests forest cover map, seral stages on the Biodiversity Guidebook. Stand structural classes are a stand-level classification system based on the size, crown closure and number of tree layers in the stand. Comparisons are made between the landscapes of today and the trends in both historic and future forests. The results indicate that current landscape conditions are much different than the they were during historic natural fire regimes. Historic landscapes were composed of more early seral stands, more open stands, and less old seral stands than the landscapes of today. Forest managers must now consider how to use our estimates of the range of natural variation (RONV). For example, they could be used as targets for forest management. Or, they may be used as an indicator of changes from historic (and future) forests, and management practices will be aimed at targets that are not necessarily historic, nor "natural".
prepared by Reg Davis.
Davis, Reg. 2006. Stand structure and seral stage projections for the Invermere TSA: final report. Forest Investment Account (FIA) - Land Base Investment Program. Forest Investment Account Report