SUM
RIZATION OF THE ECOLOGY AND GENETICS OF THE
NOBLE AND CALIFORNIA REO FIR COf!PLEX
J. F. FRANKLIN, F. C. SORENSEN, R. K. CA IPBELL
U.S.
Forest and RaJlge Fxp. Stat. Labotutory, Corvallis, Oregon 97331 Forest Seruice, Pacific Northwest
Forestry
Sciences
Noble fir (Abies procera Rehd., previously Abies nobilis (Dougl.) Lindl.),
California red fir (Abies magnifi£.'1. A. Mun.), and Shasta red fir (Abies
magnifica var shastensis Lemm,) form an important complex in She subalpine
forests along the Pacific Coast.
These are important forest trees for
commercial timber production, Christmas trees
and watershed protection.
In this paper we briefly summarize current knowledge of the ecological and
genetic features of this complex.
greatest current interest.
Emphasis is on noble fir,
the taxon of
Distribution
Noble fir is the northernmost representative of the co plex.
It generally
occupies middle- to high-elevation forest lands (1000 to 1700 m) in the Cascade
Range from the McKenzie River drainage of central Oregon (latitude about
°
44 N) north to the Stevens Pass region of northern Washington (latitude about
°
48 N),
It also occurs on isolated peaks in Oregon's northern Coast Ranges
and southwestern
Washington's Willapa Hills,
Contrary to early' reports,
noble fir does not occur in the Olympic Hountains or northern Washington
Cascade Range
(franklin 1964).
Shasta red fir was originally described from northern California.
Currently, however, the name is al'so often applied to the highly variable
populations found at high elevati ns (1400 to 2000 m) in the southern
g
Oregon Cascade Range (south of 44 N latitude), Klamath Hountains, and
133
California Coastal Ranges.
Shasta red fir populations are absent from the
northern and central Sierra Nevada Mountains but reappear in the southern
end of the range.
Typical California red fir overlaps much of the Shasta red fir range,
but it is also the sole representative of the complex in the central
Sierra Nevada.
2700
The elevational range of red fir is generally
1800
to
m.
Climatically, the range of noble fir is marked by a cooler and wetter
climate than that of the red firs, although it generally occurs at lower
elevations.
Noble fir also occupies soils that are finer textured and
richer in nutrients than those generally found with red firs.
Taxonomy
The three taxa have been treated as distinct entities by taxonomists
despite their apparent close relations.
Distinctions have been based mainly
on differences in cone and leaf morphology as well as geographic distribu­
tion.
Noble fir has bracts that are much longer than the cone scales and
strongly reflexed so that they sheath the cones;
the cone scales on California red fir,
bracts are shorter than
while Shasta red fir is intermediate
between the other two taxa in this character.
Noble fir leaves are usually
grooved on the upper surface, while those of California red fir are not.
Particular problems in identification (and questions about the validity
of the three taxa) have arisen in southern Oregon and the northern California
Coast Ranges, where populations are often highly variable.
assignable
{morphologically)
to two, or even all three,
present in some of these populations,
Individuals
of the taxa may be
Trees often resemble noble fir i n
cone a n d leaf morphology b u t a r e more like Shasta red f i r i n ecology,
seed and seedling features, and chemical compounds,
Noble and California
red fir are highly interfertile taxa and produce offspring similar in
seed and seedling characteristics to Shasta red fir (Silen, Critchfield,
and Franklin
1965),
This has led to speculation that these intermediate
southern Oregon-northern California populations may represent hybrid swarms
between noble and California red fir.
Regeneration
Noble and red firs have the largest cones of any true firs.
fir they may reach
20
em or more in length.
largest of any true firs
(U.S.
Department of Agriculture,
Forest Service
1974):
noble fir
Shasta red fir
California red fir
134
In noble
Seeds are also among the
13,500
7,300
6,400
seeds/lb,
seeds/lb, and
seeds/lb.
Good cone and seed crops are generally produced at three-year intervals,
although five or si:< years occasionally elapse between such crops
(Franklin, Carkin, and Booth 1974),
Noble fir bears cones at a younger
fndividual mature noble firs can produce
age than either red fir.
prodigious amounts of seed;
a single tree produced the equivalent of
Seed quality is related to cone
100 lbs of cleaned seed during one year.
crop size with low percentages of sound seed during poor cone crops.
Average germination of noble and red fir seedlots is often low--ranging
from 30 to 43 percent
(U.S. Department of Agriculture, Forest Service 1974).
Natural regeneration of noble fir generally takes place following
major disturbances, such as wildfire (Powells 1965).
Relatively open
areas and mineral seedbed are considered favorable conditions for seedling
establishment and growth.
It is an early successional species and generally
does not reproduce under the forest canopy;
survive only a year or two.
Pacific silver fir
Successionally,
(Abies amabilis),
seeds germinate but seedlings
it is usually replaced by
a very shade-tolerant associate.
Noble fir is con idered to be only slightly more shade tolerant than
Douglas-fir.
In fact,
the entire noble-red fir complex is distinguished
from many true firs by their relatively low shade tolerance and pioneer
status.
however,
California red fir does regenerate in natural forest stands,
although it is clearly inferior to white fir
shade tolerance,
(Abies concolor) in
Noble fir generally occurs in mixture with other species.
associates are Douglas-fir
heterophylla),
(?seudiJtsuga
Typical
menziesii), western hemlock
Pacific silver fir, and mountain hemlock
(Tsuga
(Tsuga mertensiana).
California red fir is typically associated with white fir and mountain
hemlock,
although
11pure11 stands are also common.
Grm;th and Yield
Noble fir is an outstanding timber producer.
It has a high form class
and thin bark resulting in very high volumes for a given diameter and
height of tree.
The British Forestry Commission found that the volume
increment per foot of height growth was higher than for any other conifer
they studied
(Christie and Lewis 1961).
Early height growth may be slow
relative to associated pines and Douglas-fir but is sustained for several
centuries (DeMars,
Herman, and Bell 1970).
can reach heights of 45 m a t 100 years;
90 m for old trees on similar sites.
vclumes in noble
On the best sites,
Because of high stem densities;
fir stands can also be very impressive,
325-year-old stand near
!aunt St.
noble fir
maximum recorded heights are nearly
Helens had 2,896 mJ/ha.
A superior
Natural stands
100 to 200 years in age often have volumes in excess of 1000 m3/ha.
California red fir stands may also contain large volumes (Schumacher
1928) although growth is typically slower and ma:<imum sizes and stand
volumes lower than for noble fir.
135
Noble fir is not particularly long lived.
Stands begin to senesce at
around JOO years and individuals older than ljOO years are uncommon.
The
oldest known noble fir is around 600 years.
Genetics
A number of studies of variation in the noble-California red fir
complex have been,
or are being,
chemical constituents
seedling,
(Zavarin,
conducted.
Critchfield,
Included is research on:
and Snajberk 1978);
seed,
and cone characteristics (Franklin and Greathouse 1968a,
L968b;
Sorensen and Franklin 1977); selfing (Sorensen, Franklin, and \Joollard
1976);
and seedling behavior in cold frames,
The following points are
synthesized from this work.
1. There appear to be three distinct segments to this complex:
0
o:( those populations north of about 4'-i
north latitudei
"true" noble fir)
the populations in northern California and southern Oregon from about 41°
to 44° north latitude (arbitrarily referred to hereafter as Shasta red
fir);
and the populations in the Sierra Nevada) hereafter called California
red fir.
2.
Noble fir appears quite distinct from the Shasta red fir in all
but the classic taxonomic characteristics (leaf and cone morphology),
There is strong evidence for a sharp discontinuity between these taxa at
the NcKenzie River,
The Shasta red fir populations are the most variable of the three
J,
In some features they appear intermediate between noble and California
taxa.
red fir (e.g.,
seed weight and cotyledon number) while in other responses
they are not intermediate
(e.g.,
seedling height growth in common environ­
It is possible that Shasta red fir and California red fir are parts
ment).
of a cline,
but continuity of variation is not apparent in existing studies.
The lack of continuity could be a consequence of inadequate sampling.
4.
(e.g.,
Noble fir exhibits substantial variability in some characteristics
seedling growth) but is quite uniform with regard to others
ccne and leaf morphology).
(e.g.,
Variation in either morphological or cold frame
studies does not appear to be related simply to latitude.
Substantial
variation does exist between families at a locale and between locales in
at least some characteristics.
5.
Noble fir has a high relative self fertility (0,69 in one study)
which does not appear to affect germination but can depress height growth,
6.
Noble fir and California red fir are highly interfertile.
136
Seed Collection a d Movement
With regard to noble fir seed transfer, the lack of a simple latitudinal
trend must be viewed. in conjunction with the substantial variability which
occurs among localities within a few minutes of each other in latitude or
even at the same latitude.
This pattern of variation suggests quite close
adaptation to one or more site factors which is not unexpected in a species
occupying at least moderately severe habitats.
Consequently,
the safe
course in reforestation is to use local seed especially when dealing with
the most severe sites.
If seed is moved, one should try to match habitat
of plantation with that of seed origin.
Seed should not be moved north or south across the flcKen ie River
drainage except for specific objectives.
A sharp change in genetic
characteristics of the complex takes place at this point.
137
Christie,
J.f!.,
1961.
and R.E.A. Lewis
Provisional yield tables for Abies grandis and Abies nobilis
Brit, Forestry Comn. Forest Rec,
DeMars, Donald J.,
1970.
illus.
and John F. Bell
Preliminary site index curves for noble fir from stem analysis
data.
Fowells,
Francis R. Herman,
47, 48 p.,
USDA Forest Serv.
Res.
Note P
-119,
9 p.,
illus,
H. A.
1965.
Silvics of forest trees of the United States.
Handb.
271,
762 p,,
U.S, Dept. Agric.
illus.
Franklin, Jerry F.
1964.
Some notes on the distribution and ecology of noble fir.
'
©
Northwest Sci.. .JB(l):l-13. Franklin,
Jerry F. ,
1968a.
In:
report.
Ass.,
Franklin,
Western Reforestation.
and Thomas E.
Proc.,
13-16.
Greathouse
Seed origin studies--Noble-California red fir species complex.
Western Forest Nursery Council Proceedings,
Forestry and Conservation Association,
Franklin,
A progress
Western Forestry & Conservation
Wes(;rn Reforest. Coord. Comm.
Jerry F.1
1968b.
In:
and Thomas E. Greathouse
Identifying noble fir source from the seed itself:
Jerry F.,
1974,
Richard Carkin,
Western
and Jack Booth
Seeding habits of upper-slope tree species
of cone production.
1968,
ll-l6a.
USDA For. Serv. Res,
1. A 12-year record
Note PNW-213,
12 p.
Schumacher, Francis X.
1928.
Univ,
Silen,
Yield,
Roy R.,
1965.
stand and volume tables for red fir in California,
Calif.
Agric.
Exp. Stn. Bull. 456,
William B. Critchfield,
Forest
2£!•
Sorensen, Frank C., Jerry F.
fir.
1 1(4):460-462,
Franklin,
illus.
and Robert Woollard Self-pollination effects on seed and seedling traits in noble Forest Sci,
Sorensen, Frank C.,
1977.
and Jerry F. Franklin
Early verification of a hybrid between noble and California
red firs.
"1976.
29 p.
22(2):155-159. and J.F.
Franklin
Influence of year of cone collection on seed weight and
cotyledon number in Abies
r.E.:25::er".
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Sil•1ae Genetica 26(1): 41-43.
U. S.
Department of Agriculture, ·Forest Service
Seeds of woody plants in the United
1974. Agric. Handb.
Zavarin,
450,
Eugene, W.B.
1978.
883
illus.
States.
U.S.
Dept.
Agric. ,
Critchfield, and Karel Snajberk
Geographic differentiation of monoterpenes from Abies procera·
and Abies magnifica.
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p. 133-139.
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for official use.
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