The pine family is a dominant component of natural and human-made forests in the northern hemisphere. It is found from coastal environments to the slopes of mountains; from the tropics and subtropics of Southeast Asia to the tree line in the Arctic Circle. One characteristic of pine trees is their resistance to, and for some species need for, fire. It was fire that has preserved the oldest pine fossil discovered. The charcoal fragments from Canada come from sediments 140-133 million years old. The presence of resin ducts shows that pine evolution has co-occurred with wildfires for 140 million years.