3.5.1 Wildfires Flashcards
Pyrophytic plants
Plants that can withstand fire through some mechanism.
- For example, the Baobab tree has resistant bark.
What do natural fires need?
- Fuel
- Oxygen
- A heat source
Heat sources to ignite a wildfire
1) Natural causes – lightning is particularly likely to start a fire if it occurs without much rain. Volcanic eruptions can produce very hot lava, ash or gas, which can start fires.
2) Human cases – most fires are started by people. This can be accidental, e.g. by dropping cigarettes, allowing campfires and BBQs to get out of control, or if fireworks or sparks from machinery land in vulnerable areas. Fires can also be started on purpose (arson).
Wildfires
Uncontrolled fires that destroy forests, grassland and other areas of vegetation.
Where do wildfires tend to happen in a country?
They usually occur in rural areas, but if they reach inhabited areas, they will also destroy agricultural land and settlements.
Types of wildfires
- Ground fire
- Surface fire
- Crown fire
Ground fire
Where the ground itself (e.g. peat and tree roots) burns. It is a slow, smouldering fire with no flame and little smoke.
Surface fire
Where leaf litter and low-lying vegetation burn. Fire can be low or high intensity.
Crown fire
Where fire moves rapidly through the canopy (the top layer of vegetation). Fires are likely to be intense and fast-moving.
Conditions for intense wildfires
