Residual Vegetation Patches within Natural Boreal Wild Fires: Characterizing by Pattern Metrics, Land Cover Expec tations and Proximity to Firebreak Features

Abstract

Wildfires typically contain a considerable number of wildfire residual patches of various size, shape and composition. These residual patches can occupy substantial areas of fire footprints, thus understanding their patterns provides insight for emulating forest disturbances in harvesting operations. Eleven natural boreal wild fire events within Ontario are examined. Each fire was ignited by lighting, occurred in anthropogenically undisturbed forested landscapes and was never suppressed. The spatial patterns of the residual patches are assessed based on selected spatial metrics (related to composition, configuration and fragmentation). The char acterization of the occurrence of wildfire residual patches and their spatial patterns in reference to land cover composition and proximity to firebreak features, is imperative to examine the effects of vegetation or land cover on residual patch occurrence and distribution. This study examines which land cover types are more likely to dominate the existing residual patches. The results indicate that the proportion of land area that sur vived burning varies considerably across fire events, ranging from the smallest fire event at 3% (F09) to the largest event at 21% (F06). While the majority of residual patches are in close proximity (within 200 m) to surface water and the edge of the fire footprint, it is revealed that low abundance land cover types (e.g., treed wetland and sparse conifer) tend to dominate residual patches in certain areas.