Different plants have very different ways of dealing with fire. Many large tree
s, such as Ponderosa
Pine, have thick bark
which resists fire
. This bark, along with a ‘self pruning' habit which keeps branches far off the ground, allows these trees to survive minor ground fire
s. As long as fires are common enough to prevent large scale buildup of fuel, the trees will neither have their cambium
layer in the trunks killed nor have their crowns burned. Intensity and severity are very important here because if the fire is too intense, the heat may kill the living part of the tree beneath the bark. If the trunk is exposed to flames for a long period of time, the bark may eventually burn off, leaving a fire scar
which is vulnerable to other fires in the future. Also, a very intense fire may ignite the crown, bypassing the bark and killing the tree.
Another strategy of adapting to fire is crown-sprouting. This is common in chaparral such as chamise. After a fire burns off the aboveground portion of the plant, buds may survive in the larger stems, or in the buds near the ground, which often are massed in a large ‘burl'. These buds will create new foliage, either soon after the fire or at the next rainy season. Intensity and severity of the fire here are important because an extremely severe fire may kill some or all of the buds in the stem, making the plant unable to resprout.
Many plants lay dormant in seeds which can only be dispersed or germinated in a fire. Closed-cone pines, for example, require a fire to release the seeds from their cones. The seeds then fall to the ground, in a nutrient rich, litter free environment. Other seeds lay dormant in the soil but require heat to break them open, or to trigger germination. Germination may be triggered by smoke or ash in the soil. Again, these plants are able to grow in an environment which is nutrient rich, litter free, and exposed to more sunlight and less competition than a non-burned area. Obviously, an intense fire here could possibly destroy the seeds, however there is also the danger of a small fire triggering germination into an inhospitable environment.