II. Important Characteristics of
Lodgepole Pine
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Lodgepole pine at Crater Lake is Pinus contorta
subspecies
murrayana. Some of its ecological characteristics important here
are: (1) it is a relatively small, short-lived conifer with sparse
foliage; (2) it appears to tolerate a variety of harsh environments
(wet, cold, low nutrients) which few other trees can, but (3) its growth
is considerably slowed by such conditions; (4) it is intolerant of heavy
shade; (5) its small, winged seeds are released soon after the cones
mature; (6) it is very susceptible to dwarf mistletoe, although few
trees die as a direct result of infection; (7) it is quickly killed by
mountain pine beetle; (8) it has very thin bark, even when an old tree,
rendering it susceptible to kill by fires of low intensity; (9) trees
are very subject to heart rot introduced through wounds such as fire
scars; (10) fire-affected trees appear to be very susceptible to
secondary bark beetle attack; and (11) dead trees lose their bark
rapidly and form a hard sheath, and thus logs appear to decay relatively
slowly.
Our lodgepole pine thus differs considerably from ponderosa pine, which has
thick bark even when young, gets much larger and survives much longer, appears
to be more resistant to bark beetles and can be scarred repeatedly without
rotting. It also differs significantly from its relative in the Rocky Mountains,
P. contorta ssp. latifolia in at least one way of importance to
our study (no. 5 above): many Rocky Mountain trees are serotinous, having cones
which remain closed for years until subjected to a high temperature, usually
from fire. Thus, in the Northern Rockies, the seed crop of many years is
released directly on a site following fire in lodgepole pine. In our area, seed
for regeneration must be dispersed from surviving trees or the edge of the burn,
only one year's crop at a time. This probably results in slower, more sporadic
regeneration in this area than in the Rockies, especially near the center of
large burns.
