Which phenomenon describes the burning of foliage from the bottom of a tree or small group of trees?

The phenomenon that describes the burning of foliage from the bottom of a tree or small group of trees is known as torching. This occurs when heat and flames from a fire reach the lower branches and foliage of trees, igniting them and causing the flames to rise and spread further into the tree canopy. Torching can significantly increase the intensity of a fire, as the flames can quickly consume a tree's fuel and lead to a more aggressive spread of fire through an area. This behavior can be particularly dangerous, as it makes the fire harder to control and increases the risk of it jumping to new areas.

In the context of forest fires, understanding torching is crucial for fire management and safety protocols. Firefighters need to recognize how torched trees can contribute to the development of fire behavior, including spotting and crowning, which are other significant fire phenomena.