FIRE ECOLOGY
SPECIES: Pinus ponderosa var. ponderosa | Pacific Ponderosa Pine 



FIRE ECOLOGY OR ADAPTATIONS : 
Fire is an integral part of the ecology of Pacific ponderosa pine.
Studies have shown that prior to 1900, most stands experienced
low-severity surface fires at intervals ranging from 1 to 30 years.
Fire scars and pollen analysis trace this phenomena back to at least
A.D. 1500.  Fire has allowed Pacific ponderosa pine to dominate sites
where it is the potential climax as well as sites where it is seral to
more shade-tolerant tree species [2,22,26,39].

Pacific ponderosa pine has evolved with a thick bark and open crown
structure that allows it to survive most fires.  Mature trees will
self-prune, leaving a smooth bole which reduces aerial fire spread.
Other fire adaptations include deep roots, high foliar moisture content,
insulated bud scales, and medium to light lichen growth [16,17,54].
Seedlings prefer the mineral-soil seedbeds created by fire [42].

Fire also shapes the composition of Pacific ponderosa pine stands.  In
the late 1800's stands exhibited open parklike appearances with
well-stocked overstories and relatively few understory trees.  Fire
suppression, however, has allowed the unnatural buildup of forest fuels
which has increased the occurrence of stand-replacing fires.  Over the
last 100 years of fire suppression, seral Pacific ponderosa pine stands
have been replaced by shade-tolerant climax stands [2,22,26].


POSTFIRE REGENERATION STRATEGY : 
   Crown-stored residual colonizer; short-viability seed in on-site cones
   Off-site colonizer; seed carried by wind; postfire years 1 and 2
   Off-site colonizer; seed carried by animals or water; postfire yr 1&2

Related categories for Species: Pinus ponderosa var. ponderosa | Pacific Ponderosa Pine