|
Wildlife, Animals, and Plants
|
|
FIRE ECOLOGY
SPECIES: Cupressus forbesii | Tecate Cypress
FIRE ECOLOGY OR ADAPTATIONS :
Tecate cypress is a fire-adapted, fire-dependent species [7,39,42]. It
exhibits adaptations that indicate "strict dependence on fires of a
particular frequency". These adaptations include serotinous cones,
resinous foliage that is highly flammable when dry, thin bark, and a
mixed chaparral habitat that ensures heavy fuels and a fuel ladder into
the canopy when trees are at their reproductive peak (age 40+ years).
Before this age, the biomass of the community is lower, and there is
considerably less dead material in and under the canopy. At about age
40 years, the cypress begin completely overtopping the shrub species,
limiting the availability of light to the shrubs. This period, when the
base of the cypress canopy is at about the same level as the top of the
shrub canopy, is the time of greatest flammability in the stand. At 80
postfire years, stand flammability may decrease because a closed-canopy
stand of Tecate cypress, almost devoid of an understory, develops
[7,44].
Cypress trees of southern California have serotinous cones that persist
on trees for years [17,44]. Some Tecate cypress cones remain on trees
for over 8 years [39]. Cone opening in the California cypress species
is erratic and almost negligible except when cones are exposed to
extreme heat; then it is rapid and uniform [44]. When opened by the
heat of a fire, the seeds fall on exposed mineral soil [17,40]. Most
seed falls in the first months following fire [44]. When fires occur in
late summer and fall and are followed by winter rains, seed is
disseminated on moist, bare mineral substrates. These are optimum
conditions for cypress seed germination [39]. Successful Tecate cypress
reproduction is generally restricted to burned sites [19,42,43] or to
washes where seeds have germinated after water dispersal [1].
According to Armstrong [1], Tecate cypress has had an average interval
between fires of 25 years during the last century, with a range of 15 to
63 years [1,39]. However, Keeley [14] estimated natural fire frequency
from 50 to 100 years for Tecate cypress communities based on
reproductive rate data [1,7,41].
POSTFIRE REGENERATION STRATEGY :
Tree without adventitious-bud root crown
Crown residual colonizer (on-site, initial community)
Initial-offsite colonizer (off-site, initial community)
Related categories for Species: Cupressus forbesii
| Tecate Cypress
|
 |