How topography effects fire movement and impacts stand structure in a Boreal forest

Abstract This survey is the conclusion of a series of surveys that have investigated fire ecology in the Oulanka valley. It is the intended climax of these studies to culminate with a prescribed burn in the valley, the data collected will facilitate the prediction of fire movement, intensity and the subsequent impacts upon the post recovery vegetation community. The influence of topography upon fire movement is well documented, after a climate of fire suppression, prescribed burning is now being reintroduced as a disturbance tool, as a result there is a need to redevelopment a knowledge base. Due to this successful suppression, fire is no longer a significant ecological factor in maintaining a landscape mosaic in a boreal forest ecosystem. This study has investigated the landscape impacts of fire on stand structure and the outcomes of fire recovery on tree regeneration and deadwood. Data was gathered on tree species composition by line transects in combination with GPS data, the results were then plotted onto a GIS system to record stand structures. The results have shown that the river can greatly influence the movement and intensity of fire along the valley. The intensity is greater on the river plains and it diminishes as it moves up slope into old growth forest. Some sections of the valley are more susceptible to successful ignition and as a result these areas may be in a permanent state of regeneration, while others remain virtually fire free. Fire increases the availability of standing deadwood, which is a key resource for the presence of cavity species, these are keystone modifiers for other species. In the fire study sites 48 snags per hectare were recorded with a basal volume of 2.79 m²/ha, indicating suitable densities for the presence of Picoides tridactylus