An area's fire environment is determined by the interactions of climate conditions, the types of fuels available, and ignition sources. Together these conditions determine the frequency and intensity of fires, and the amount of fuel consumed and fire size. The frequency of wildfires depends on ignition sources and weather conditions which may help a fire spread. The intensity depends on the quantity of fuel available and how easily it will burn. These factors are quite interdependent, and their interaction is influenced by wind and topography.
Trees actually record fire history.
Each year a tree adds a layer of cells, increasing the width of its trunk. When a fire passes through a forest, some trees are only scorched. This adds a layer of charcoal which is eventually enveloped by a layer of new growth. Over time, these charcoal layers provide a record that scientists can use to determine when and how often fires have occurred. The Carolina Sandhills staff uses fire as a catalyst that promotes changes in the ecosystem.