To survive a wildland fire, most plants have adaptive traits or abilities that allow them to reproduce or regenerate after the fire. To survive a fire, a plant must be able to insulate itself from the heat of the flames. Bark thickness is one of the most important factors determining fire resistance of trees. Ponderosa pine, longleaf pine, slash pine, burr oak and giant sequoia in the United States, and the corkoak on the Iberian Peninsula, are examples of trees with thick bark that acts as insulation. Small woody plants and shrubs, which normally have thin bark, tend to use the soil as an insulating layer to protect themselves.
Some plants protect their buds as an adaptive strategy to survive a fire.
Buds can be protected by layers of succulent foliage. The buds of the longleaf pine are protected by a thick cluster of needles. Some plants even protect their buds by locating them within the main stem and roots. A few species of poplar trees in several parts of the world possess this trait. Retention of seeds by plants until a fire does occur and stimulation of seed dispersal by fire are other examples of fire adaptation.