🚀 go-pugleaf

Pam wrote:
> With this diversity of locations, questions have been raised about the
> limitation of its native range and habitat. Apparently outside of its
> native Sierra Nevada, the giant sequoia is unable to re-seed itself
> by natural means.

From http://www.fs.fed.us/database/feis/plants/tree/seqgig/fire_effects.html
This might be part of the problem.

FIRE EFFECTS

SPECIES: Sequoiadendron giganteum


----------------------------------------------------------------------------
----




IMMEDIATE FIRE EFFECT ON PLANT :
In Sequoia and Kings Canyon National Parks, a moderate-severity
prescribed fire contributed little to the mortality of giant sequoia
that were larger than 1 foot (0.30 m) d.b.h.  Additionally, there is no
evidence that previous fire scarring had any relationship to tree
mortality [5].  Low- to moderate-severity fires scorch the bark of giant
sequoia and usually cause scarring.  High-severity fires may reach the
crown and consume part or all of the canopy cover [2].  A direct
relationship exists between the size of the basal fire scar in mature
giant sequoias and the the likelihood of damage to the top or foliage of
the trees [23].  Reduction of supporting wood from scarring predisposes
the tree to falling, and provides an opening for fungi responsible for
root disease and heart rot [28].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
Despite the general belief that giant sequoia wood is not especially
flammable, it burns hotly when splintered and dry [10].


PLANT RESPONSE TO FIRE :
High-severity fires will generally kill pole-size and younger trees.
Immediately following the passage of fire, seeds will drop as a reaction
to hot convectional air movement through the canopy.  Seeds will
germinate on the favorable mineral seedbeds created by the fire [5].

Postfire seedling establishment:  When high-severity fires burn in dense
stands of mature giant sequoias, as many as 40,485 seedlings per acre
(100,000/ha) may develop following heat-induced seedfall [11].  After a
prescribed burn in Sequoia and Kings Canyon National Parks, a
high-severity burn resulted in 40,000 seedlings per acre (98,800/ha) the
first year after burning.  A lower-severity burn resulted in 13,000
seedlings per acre (32,110/ha).  Not a single giant sequoia seedling was
found on the unburned control plot in this study [5].

--
Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8b
Sunset Zone 5
Has 2 very small Sequoiadendron giganteum in his yard.