Fire history

It gives an estimate of a natural disturbance regime's historical range of variability and can be used to identify the processes affecting fire occurrence.

Sustained wildfire can only exist once oxygen levels and fuel sources are present in sufficient quantities.

[1]: 11–14  The presence of fusain (fossil charcoal), beginning in the early Carboniferous attests to this fire history and forms an important element of the Cretaceous–Paleogene boundary.

Large cells can quickly divide rapidly at the beginning of the growing season, creating a light-colored wood.

When growth slows down, generally in colder months, a darker wood is created from smaller cells, dividing more slowly.

For example, tree-ring dating of large stands will show the age of the forest and may provide an estimate of when the last significant disturbance event occurred.

Before Euro-American settlement in western North America, fire histories from scars preserved in ponderosa pine forests often reveal a pattern of frequent fire (often with 5 to 20-year intervals in a single area), with a pattern in time and space strongly related to past variations in climate.