FIRE ECOLOGY
SPECIES: Pinus cembroides | Mexican Pinyon 



FIRE ECOLOGY OR ADAPTATIONS : 
Community composition and the spatial distribution of intermixed woody
species and understory species influence the effect fire has on Mexican
pinyon.  Despite its thin bark, mature Mexican pinyon is relatively
resistant to low- to moderate-severity fires.  Mexican pinyon more than
80 years old have survived at least four fires, including one of
moderate severity, in Big Bend National Park, Texas [62].  Seedlings
probably establish from bird and rodent caches following fire.

Mexican pinyon belongs to diverse communities with varying fire regimes.
Historically, fires probably occurred every 10 to 30 years in
pinyon-juniper woodlands.  Fire is the primary cause of secondary
succession in pinyon-juniper woodlands [42].

Pygmy conifer-oak scrub on steep, rocky slopes and crests develops in
response to fire and drought [67].  It is fire adapted and its structure
is maintained by periodic fires [95].

Madrean oak-pine woodlands probably are fire-tolerant, fire-maintained
communites.  The fire regime is not well understood for these
associations [21,82].  Mexican pinyon occurs in a Madrean oak-pine
woodland in Rhyolite Canyon in Chiricahua National Monument, Arizona.
Historically, surface fires occurred here in 1- to 38-year intervals.
The fire regime has become longer here and elsewhere since livestock
grazing has reduced surface fuels [21,83].

In a Madrean evergreen woodland in Boot Canyon in Big Bend National
Park, Texas, ring counts from fire scarred Mexican pinyon indicated that
at least 10 fires occurred between 1770 and 1940, an average of about 1
every 20 years.  Low-severity surface fires do not always produce scars
on Mexican pinyon.  Additionally, cross dating with other species is
necessary due to missing growth rings in Mexican pinyon [62].  Average
intervals between scar-producing fires were estimated at possibly 70
years for seven sites in the Chisos Mountains in Big Bend National Park
[62,82].



POSTFIRE REGENERATION STRATEGY : 
   Tree without adventitious-bud root crown
   Initial-offsite colonizer (off-site, initial community)
   Secondary colonizer - off-site seed

Related categories for Species: Pinus cembroides | Mexican Pinyon