David F. Olson, Jr., Douglass F. Roy, and Gerald A. Walters
Redwood (Sequoia sempervirens), also called coast redwood and California redwood, is native to the central and northern California coast, a region of moderate to heavy winter rain and summer fog so vital to this tree. It is one of three important North American trees of the family Taxodiaceae. Close relatives are the giant sequoia (Sequoiadendron giganteum) of the Sierra Nevada in California and the baldcypress (Taxodium distichum) of the southeastern states.
Redwood is a native, evergreen, long-lived (greater than 2,200 years), monoecious tree [38,40] (monoecious = "having reproductive organs typical of both sexes in a single individual"). Redwoods are among the world's tallest trees; trees over 200 feet (61 m) are common, and many are over 300 feet (91 m) . The largest tree thus far was measured at 364 feet (110.3 m) in height and 20 feet (6.1 m) in d.b.h. ("diameter at breast height") . The root system is composed of deep, widespreading lateral roots with no taproot [40,44]. The bark is up to 12 inches (30 cm) thick and quite fibrous . Redwood self-prunes well in dense stands ; the base of the bole is strongly buttressed .
Redwood is endemic to the coastal area of northern California and southwestern Oregon. The redwoods occupy a narrow strip of land approximately 450 miles (724 km) in length and 5 to 35 miles (8-56 km) in width. The northern boundary of its range is marked by two groves on the Chetco River in the Siskiyou Mountains within 15 miles (25 km) of the California-Oregon border [22,40]. The southern boundary of redwood's range is marked by a grove in Salmon Creek Canyon in the Santa Lucia Mountains of southern Monterey County, California .
Redwood occurs in a maritime Mediterranean climate, where the winters are cool and rainy, and the summers are dry. The mean precipitation is 70 inches (180 cm), with 90 percent falling between October and May. The dry summers are mitigated by a heavy fog belt . The fog reduces the drought stress of this hydrophilic plant by reducing evapotranspiration and adding soil moisture. Redwoods beyond the fog belt appear to be limited to areas of high moisture. Currently there is considerable debate over the link between the fog belt and redwood distribution .
Global Range: Pacific slope of the northern half of the Coast Range of California (from Monterey Co. northward), and adjacent southwestern-most Oregon. Generally found within 5-35 miles of the ocean, and apparently dependent on coastal humidity and fog (Griffith 1992).
Regularity: Regularly occurring
Occurrence in North America
southwestern Oregon. The redwoods occupy a narrow strip of land
approximately 450 miles (724 km) in length and 5 to 35 miles (8-56 km)
in width. The northern boundary of its range is marked by two groves on
the Chetco River in the Siskiyou Mountains within 15 miles (25 km) of
the California-Oregon border [22,40]. The southern boundary of
redwood's range is marked by a grove in Salmon Creek Canyon in the Santa
Lucia Mountains of southern Monterey County, California .
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
1 Northern Pacific Border
3 Southern Pacific Border
- The native range of redwood.
Redwood is a native, evergreen, long-lived (greater than 2,200 years),
monoecious tree [38,40]. Redwoods are among the world's tallest trees;
trees over 200 feet (61 m) are common, and many are over 300 feet (91 m)
. The largest tree thus far was measured at 364 feet (110.3 m) in
height and 20 feet (6.1 m) in d.b.h. . The root system is composed
of deep, widespreading lateral roots with no taproot [40,44]. The bark
is up to 12 inches (30 cm) thick and quite fibrous . Redwood
self-prunes well in dense stands ; the base of the bole is strongly
crown narrow; branches slender on young trees, finally stout, borne horizontally or basal ones deflexed. Leaves bright deep green adaxially, ca. 6 mm on main branchlets, 0.8-2 cm on lateral branchlets, midvein raised abaxially. Pollen cones ovoid, 1.5-2 mm; pollen yellow-green. Seed cones very small at pollination, maturing pale reddish brown, ovoid-elliptic or ovoid, 2-3.5 × 1.2-1.5 cm; cone scales shield-shaped, apically grooved, expanded into a rhomboid disc, occasionally with central mucro. Seeds pale brown, elliptic-oblong, ca. 1.5 mm; wing as wide as seed.
Habitat and Ecology
Comments: Coastal forests of northern and central California and southernmost Oregon.
Redwood occurs in a maritime Mediterranean climate, where the winters
are cool and rainy, and the summers are dry. The mean precipitation is
70 inches (180 cm), with 90 percent falling between October and May.
The dry summers are mitigated by a heavy fog belt . The fog reduces
the drought stress of this hydrophilic plant by reducing
evapotranspiration and adding soil moisture. Redwoods beyond the fog
belt appear to be limited to areas of high moisture. Currently there is
considerable debate over the link between the fog belt and redwood
Preferred sites for redwood stands are alluvial fans, coastal plains,
and benches along large streams . The size of a redwood can be site
dependent: a 400-year-old specimen on a hillside had a d.b.h. of 2 feet
(0.6 m), while a 600-year-old specimen on an alluvial fan had a d.b.h.
of 12 feet (3.6 m) .
Elevation: Redwood occurs at elevations ranging from sea level to 3,000
feet (0-915 m), but most stands occur from 100 to 2,320 feet (100-703 m)
[11,40]. Redwoods are sensitive to salt spray , and are usually
separated from the coast by intervening grassland 
Soils: Redwood has a strong affinity for deep, moist soils in the
Inceptisol and Ultisol soil orders . The common parent materials
are graywacke sandstones, shales, and conglomerates .
Associates: In addition to those previously listed under Distribution
and Occurrence, overstory associates include Sitka spruce (Picea
sitchensis), Pacific yew (Taxus brevifolia), California torreya (Torreya
californica), Gowen cypress (Cupressus goveniana), bishop pine (Pinus
muricata), Monterey pine (P. radiata), bigleaf maple (Acer macrophyllum),
Oregon white oak (Quercus garryana), and Oregon ash (Fraxinus latifolia)
Understory associates include vine maple (Acer circenatum), chittam bark
(Rhamnus purshiana), evergreen huckleberry (Vaccinium ovatum), Pacific
rhododendron (Rhododendron macrophyllum), salmon berry (Rubus
spectabilis), and evergreen ceanothus (Ceanothus velutinus) .
Key Plant Community Associations
Redwood is listed as a dominant or codominant overstory species in the
Coast redwood ecological types of southern Monterey County, California .
Terrestrial natural communities of California .
The redwood forest and associated north coast forests .
Forest associations of Little Lost Man Creek, Humboldt County,
California: Reference-level in the hierarchical structure of
old-growth coastal redwood vegetation .
Preliminary plant associations of the Siskiyou Mountain Province .
Tanoak series of the Siskiyou Region of southwest Oregon .
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
229 Pacific Douglas-fir
234 Douglas-fir - tanoak - Pacific madrone
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
K002 Cedar - hemlock - Douglas-fir forest
K006 Redwood forest
K028 Mosaic of K002 and K026
K029 California mixed evergreen forest
Soils and Topography
High-site soils for redwood consist of Xerochrepts, Haploxerults, and Haplohumults of the Hugo, Josephine, Melbourne, Empire, Sites, and Larabee series (orders Inceptisols and Ultisols) and associated alluvial soils. The high-site residual soils have been derived from either consolidated or soft sedimentary rocks. In the Coastal Forest Practice Act District of California, which encompasses the natural range of redwood, the Hugo soil series predominates. In current soil taxonomic terms, the Hugo series is a Typic Distrochrept of the order Inceptisols (45,46). It is a member of a loamy-skeletal, mixed, mesic family, typically pale brown, moderately acid, gravelly (sandy) clay loam A horizons, and pale brown, strongly acid gravelly (sandy) clay loam B horizons. Limits of redwood forests sometimes are determined by soil types. For example, redwood does not grow on soils having high amounts of magnesium and sodium.
Fertility of soils under redwood stands has been studied by measuring the replaceable calcium concentration, expressed in equivalents, present in a square meter (10.76 ft²) to a depth of 30 cm (12 in). This measure indicates fertility best because it separates nutritional properties from other environmental effects. Equivalents ranged from 4 to more than 80, with 63 appearing to be optimum (49).
Soil nutrient levels that were observed to change during harvest of old-growth or second-growth redwood recovered to nearly original values during regrowth. In the one-meter soil profile, carbon, nitrogen, phosphorus, and exchangeable potassium and sodium increased in amount, while calcium decreased (52). Soil organic matter showed a small decline and recovery after logging (18).
The lowest amount of soil moisture available during the year has been related to minimum basal area growth of redwood stands. Basal area is used as an index of stand development. This minimum available soil moisture, expressed as a percentage of storage capacity, ranged between 18 and 86, with 62 correlated with maximum basal area (49).
The redwood region, generally, is characterized by irregular ridges oriented northwest to southeast with deep narrow valleys. Consequently, the principal streams drain to the northwest. Much of the terrain is rough, steep, and extremely dissected both by major streams and smaller drainages. Redwoods grow from sea level to about 915 m (3,000 ft) elevation, but most are found between 30 and 760 m (100 and 2,500 ft). The best stands have developed on flats and benches along the larger streams, on moist coastal plains, river deltas, moderate westerly slopes, and valleys opening toward the sea.
Although most redwood stands are close to the ocean, redwood does not tolerate ocean winds, and considerable evidence suggests that it is sensitive to ocean salts carried inland during storms. Usually redwoods do not grow on hillsides that face the ocean. The absence of redwood near the ocean also may be caused by the absence of forest soils of sufficient depth and fertility to support redwood.
Redwoods are smaller and give way to other species as altitude, dryness, and slope increase. In the north, redwoods clothe all exposures and reach their maximum development as forest trees. In the southern part of the range, redwoods are restricted to western or northern exposures, and at the extreme southern extension they are restricted almost entirely to the bottoms of narrow canyons that cut through steep foothills abutting the ocean. Trees near the mouths of these canyons often are exposed to onshore winds and frequently have flat tops with dead limbs on the windward side. This effect has been attributed to the trees' inability to replace moisture lost through desiccation by winds.
On alluvial flats, where redwoods reach their maximum development, soils have been built up by deposits of sediment from successive floods. In one area the ground level has been raised 3.4 m (11 ft) in 700 years. In another, repeated flooding in the past 1,000 years deposited nearly 9.1 m (30 ft) of silt and gravel around the bases of many large redwood trees. Deposits from a single flood have been as deep as 76 cm (30 in). Redwoods adapt to the new ground levels by originating new and higher root systems (43,51). This flooding generally kills competing species and thereby allows redwood to maintain nearly pure stands on such plains.
Annual precipitation varies between 640 and 3100 mm (25 and 122 in) and is mostly winter rain, although snow sometimes covers the highest ridges. Generally, January is the wettest month and July is the driest. With substantial precipitation in all months except summer, only slight summer drought on deep soils, and mild winters, the climate is productive, and some of the world's grandest forests are indigenous to it (34).
The frequent summer fogs that blanket the redwood region seem to be more significant than the amount of precipitation in delineating the redwood type. The major effect of fog is to decrease water loss from evaporation and transpiration. An additional effect of condensation and fog drip from tree crowns is an increased soil moisture supply during the dry summers (1). The natural range of redwood is limited to areas where heavy summer fogs from the ocean provide a humid atmosphere, although its successful growth in plantations or amenity plantings is not as limited. Redwood is among the most successful trees in the Central Valley of California, and at low elevations in the Sierra Nevada. It grows well at considerable distance from the ocean in New Zealand, France, Spain, and elsewhere (26,27).
Habitat & Distribution
Plant / associate
fruitbody of Buchwaldoboletus lignicola is associated with rotting wood of Sequoia sempervirens
Other: major host/prey
Plant / associate
fruitbody of Calocybe obscurissima is associated with Sequoia sempervirens
Other: major host/prey
Foodplant / saprobe
gregarious or scattered apothecium of Chloroscypha chloromela is saprobic on fallen twig of Sequoia sempervirens
Other: sole host/prey
Plant / associate
fruitbody of Geastrum fimbriatum is associated with Sequoia sempervirens
Foodplant / saprobe
fruitbody of Hemimycena lactea is saprobic on dead debris of Sequoia sempervirens
Foodplant / pathogen
fruitbody of Phaeolus schweinitzii infects and damages live root of mature tree of Sequoia sempervirens
Other: minor host/prey
Foodplant / saprobe
fruitbody of Radulomyces confluens is saprobic on dead, decayed wood of Sequoia sempervirens
Other: unusual host/prey
Foodplant / saprobe
fruitbody of Sparassis crispa is saprobic on dead root of Sequoia sempervirens
Other: minor host/prey
Foodplant / saprobe
convex, pluriloculate stroma of Cytospora coelomycetous anamorph of Valsa abietis is saprobic on dead twig of Sequoia sempervirens
Foodplant / saprobe
fruitbody of Vesiculomyces citrinus is saprobic on dead, decayed bark of Sequoia sempervirens
Other: major host/prey
Associated Forest Cover
Pure stands of redwood are found only on some of the best sites, usually the moist river flats and gentle slopes below 305 m (1,000 ft). Although redwood is a dominant tree throughout its range, generally it is mixed with other conifers and broad-leaf trees.
Douglas-fir (Pseudotsuga menziesii) is well distributed throughout most of the redwood type. Distributions of other conifer associates are more limited. Significant species on the coastal side of the redwood type are grand fir (Abies grandis) and western hemlock (Tsuga heterophylla) north from northern Sonoma County, CA, and Sitka spruce (Picea sitchensis) north from the vicinity of Humboldt Bay, CA.
Conifers associated less commonly on the coastal side of the redwood type are Port-Orford-cedar (Chamaecyparis lawsoniana), Pacific yew (Taxus brevifolia), western redcedar (Thuja plicata), and California torreya (Torreya californica). Other conifers found with redwood include Gowen cypress (Cupressus goveniana) and several species of pine, including bishop pine (Pinus muricata), knobcone pine (P. attenuata), lodgepole pine (P. contorta), Monterey pine (P. radiata), and sugar pine (P. lambertiana).
The two hardwoods most abundant and generally distributed in the redwood region are tanoak (Lithocarpus densiflorus) and Pacific madrone (Arbutus menziesii). Other hardwoods found with redwood include vine maple (Acer circinatum), bigleaf maple (A. macrophyllum), red alder (Alnus rubra), giant chinkapin (Castanopsis chrysophylla), Oregon ash (Fraxinus latifolia), Pacific bayberry (Myrica californica), Oregon white oak (Quercus garryana), cascara buckthorn (Rhamnus purshiana), willows (Salix spp.), and California-laurel (Umbellularia californica).
Of the great variety of lesser vegetation found in association with redwood, these species are especially common: bracken (Pteridium aquilinum var. lanuginosum), sword fern (Polystichum munitum), salal (Gaultheria shallon), blueblossom (Ceanothus thyrsiflorus), California huckleberry (Vaccinium ovatum), Pacific rhododendron (Rhododendron macrophyllum), salmonberry (Rubus spectabilis), coyote-brush (Baccharis pilularis), and snowbrush (Ceanothus velutinus).
Diseases and Parasites
Old-growth redwood stands show evidence of three or more severe fires each century (23,44). In many instances, fires may only reduce the thickness of the protective bark, which may be more than 30 cm (12 in) thick. In other instances, fires cause basal wounds through which heart rots enter. The combination of recurring fires and advancing decay produces large basal cavities called "goose pens." In extreme instances, mature trees may be so weakened mechanically that they fall.
In its northern range, in and around Redwood National Park, CA, fire has a moderate ecological role in redwood stands. Light ground fires that do not open the canopy favor western hemlock regeneration but usually eliminate older hemlock from the stand. Douglas-fir establishment is infrequent and unsuccessful under a full overstory canopy, even following light ground fires on mesic sites. Relatively hot fires appear essential for the establishment of Douglas-fir trees in discrete age classes. Redwood, grand fir, and tanoak maintain their status in redwood stands with and without the influence of fire (47,48).
Frequency distributions of fires indicate a natural pattern of several short intervals between fires followed by one or more long interval. This suggests that prescribed burning to maintain ecosystems should also be done on a short-short-long interval pattern (23).
Redwood has no tree-killing diseases other than seedling diseases previously listed, but heart rots cause extensive cull. Most common heart rot in the southern part of the range of redwood is a brown cubical rot, caused by Poria sequoiae. Most significant farther north is a white ring rot caused by P. albipellucida (5,22).
A twig branch canker (Coryneum spp.) has been observed on sprouts and plantation trees of seedling and sapling size. This canker, which girdles stems and branches, could become damaging in plantations (5,22).
Several insects are found on redwood but none cause significant damage. These include a flatheaded twig borer and girdler (Anthaxia aeneogaster), two redwood bark beetles (Phloeosinus sequoiae and P. cristatus), and the sequoia pitch moth (Vespamima sequoiae) (21).
Bark stripping by the American black bear has caused serious damage in some parts of the redwood region. Wide strips of bark are ripped from the tree, often from the top to the ground, during April to August. Trees 10 to 30 years old and 15 to 25 cm (6 to 10 in) in diameter are damaged most and many may be girdled. Woodrats often injure planted trees on cutover land and occasionally attack sprouts and larger trees.
In a few instances, redwood is deformed by fasciation, a flattening of the normally cylindrical stem by formation of a row of linked meristems. The causes of most fasciations are unknown (40).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 - 300
Comments: Frequent within its geographic range, which extends from southwestern Oregon to Monterey County, California.
Fire Management Implications
Flame length and fuel consumption were found to be the most important
parameters in determining top-kill and basal sprouting. These
parameters can be easily controlled by use of different firing patterns
and fuel moisture to achieve the desired effects from a prescribed fire.
A regime of periodic prescribed fire would elevate the probability of
sprout regeneration being top-killed by preventing large fuel
June 1990 Low consumption burn
October 1989 High consumption burn
Fire Management Considerations
A fire regime where prescribed fire substitutes for lightning and
now-absent aboriginal ignitions may have to be implemented to maintain
or reestablish presettlement conditions in old-growth or cutover redwood
forests . McBride and others  recommend that both frequency
distributions of fire intervals and an analysis of the pattern of fire
intervals be used as a basis for determining reburn intervals for
prescribed fire. They evaluated the fire history of redwood forest
stands in Muir Woods National Monument and, because of the highly skewed
frequency distribution observed in this type, suggested that the average
fire interval would be inappropriate to use as a reburn interval.
Instead a combination of shorter than the average and longer than the
average natural fire interval was recommended. In areas where fire has
been excluded for many decades, a prescribed fire program should start
with two short-interval fires (less than average interval) to reduce
high fuel accumulations. Once the fuel load has been reduced, a burning
pattern of two short fire intervals followed by a long interval should
be implemented .
Person and Hallin  reported that regeneration was 5 to 10 times
greater on cuts with moderate to hot slash fires than on those with cool
or no slash fires. Hallin  proposed the following guidelines for
(1) burn at night
(2) do not burn during the dry season (June thru September)
(3) light winds
(4) keep the area small (less than 40
acres [16 ha])
(5) slash loads pulled away from advance regeneration
If sprouts are to be used as part of stand regeneration, the stumps
should not be debarked or severely burned during slash disposal, as
these actions will result in lowered sprout stocking .
Finney  has developed equations to estimate the fuel loading of the
forest floor in redwood stands based on forest floor depth.
Broad-scale Impacts of Plant Response to Fire
After crown-kill redwood sprouts new foliage from dormant buds along the
bole. The bole is covered with fine feathery foliage extending 2 to 3
feet (0.6-0.9 m) out from the bole. This manifestation is called a
fire-column. Over time the narrowed crown will again develop into a
typical crown. During the first 4 postfire years the tree will produce
very few strobili .
After top-kill, the number of sprouts per root crown depends on the
severity of the fire. Severe heat influx to the root crown kills more
of the dormant buds, thus reducing the number of sprouts; however, this
allocates more of the carbohydrate reserves to fewer sprouts, which
results in larger and taller sprouts .
In northwestern California, Finney and Martin [14,16] found stump sprouts
were less likely to survive prescribed fire than redwood seedlings. Large
redwoods survived prescribed fire. For further information, see Fire Case Studies.
Plant Response to Fire
After fires that destroy all aboveground portions, both mature and young
redwoods will sprout from the root crown ; even seedlings have the
ability to sprout after top-kill . After fires that destroy the
crown, redwoods greater than 8 inches (20 cm) will sprout from numerous
dormant buds along the bole and produce new foliage (see fire case
Redwood can also reestablish after fire via on-site and off-site seed
Broad-scale Impacts of Fire
Young trees originating from stump sprouts have a higher rate of
top-kill after fire than those originating from seedlings (see fire case
Basal wounding provides a vector for heart rot to enter the tree. Once
this has occurred, recurring fires and basal decay produce large basal
cavities, called goosepens, that weaken the tree .
Immediate Effect of Fire
The effect of fire on redwood varies depending on the size of the tree.
The bark of young trees (less than 8 inches [20 cm] d.b.h.) is generally
too thin to protect the cambium from damage, and trees of this size are
usually top-killed by cool to hot fires . The thick bark of mature
redwood insulates the cambium from the heat of the fire , and in
many cases, fire may only reduce bark thickness . Under more severe
circumstances, such as stand-replacing fires, basal wounding and
top-kill occurs .
Tree with adventitious-bud root crown/root sucker
Ground residual colonizer (on-site, initial community)
Crown residual colonizer (on-site, initial community)
Secondary colonizer - on-site seed
Secondary colonizer - off-site seed
Fire has had an ecological role in the redwood forest type . The
mean fire interval (MFI) prior to human occupation was approximately 135
to 350 years, and after human influx (about 11,000 years ago) decreased
to approximately 17 to 82 years . Redwood has adapted to this fire
regime, and mature redwoods are considered very resilient to fire. The
thick bark; great height; and ability to sprout from the root crown or
from dormant buds located under the bark of the bole and branches are
adaptations that allow redwood to survive cool to hot fires .
More info for the term: climax
Facultative Seral Species
Obligate Climax Species
Redwood is classified as a shade-tolerant to very shade-tolerant species
due to its high photosynthetic capacity at low light levels .
Redwood releases well even at quite an old age. One specimen after
1,000 years released from 30 to 6 rings per inch (12-2.4 rings/cm) .
There is some debate over the classification of redwood as a climax
species. Some consider redwood a climax species, while others consider
it a fire-dependent seral species [15,41,54,55]. Osburn and Lowell 
reported that if fire is excluded from Redwood National Park over the
next 2,000 years redwood will disappear, and Sitka spruce, western
hemlock (Tsuga heterphylla), and western redcedar (Thuja plicata) will
dominate. Viers  on the other hand reported that redwood is a
climax species in the vicinity of Redwood National Park because it
maintains uneven age distributions with or without fire.
After disturbance redwood dominates in early seres due to its ability to
In the floodplain environment redwood deploys what has been called "the
endurer strategy." After flooding and stem burial, redwood will develop
a new and higher lateral root system from buried buds on the bole of the
tree. While the repeated flooding and deposition of soil (often to
depths of 30 inches [76 cm]) kills competing vegetation, redwood endures
Redwood reproduces both sexually and asexually. The male and female
strobili are borne separately on different branches. Redwood begins
producing seeds at 5 to 15 years of age. Large seed crops occur
frequently, but viability of the seed is low . A dry period during
pollination allows better pollen dispersal and improves seed viability.
The seeds are small and light, averaging 120,000 seeds per pound
(265,000 seeds/kg). The wings are not effective for wide dispersal
, and seeds are dispersed by wind an average of only 200 to 400 feet
(61-122 m) from the parent tree .
Redwood seeds do not require pretreatment to germinate. Germination is
epigeal ; the best seedbed is moist mineral soil with some shade
[17,36]. Germination rates are generally low due to low viability
rather than to dormancy. Germination rates with a mean of 10 percent
are the norm .
Seedlings require adequate moisture to survive. The roots of redwood
seedlings do not have root hairs and are thus inefficient at extracting
soil moisture. Once established seedlings can obtain remarkable growth
rates in the first season. Growth of 18 inches (46 cm) is not uncommon.
Older saplings (4 to 10 years old) can grow 6.5 feet (2.0 m) in one
growing season .
Redwoods can reproduce asexually by layering or sprouting from the root
crown or stump. Sprouts from the root crown are generally favored for
tree crops ; sprouts originating from the stump are generally not as
vigorous as root-crown sprouts, and are very susceptible to wind throw
. Sprouts originate from dormant or adventitious buds at or under
the surface of the bark [17,40]. The formation of these buds occurs at
a young age, as even seedlings have been observed to sprout after
top-kill . The sprouting capacity of redwood decreases with size
and age . Sprouting appears to be the greatest on the downhill side
of the tree . Within a short period after sprouting each sprout
will develop its own root system, with the dominant sprouts forming a
ring of trees around the parent root crown . The mean crop tree
sprouting potential per root crown is five, which adds many crop trees
to a given site .
Sprouts can achieve heights of 7 feet (2.1 m) in a single growing
season. Shading does not decrease sprout height, but it does reduce the
number and weight of sprouts . Density of sprouts also affects
sprout vigor; the higher the density, the less vigorous the sprouts
Growth Form (according to Raunkiær Life-form classification)
slopes ranging from 30 to 40 percent. The elevation of the plots ranged
from 240 to 350 meters (792-1,155 ft).
On the Humboldt site the plots were located on a southern exposure with
slopes ranging from 10 to 40 percent. The elevation of the plots ranged
from 350 to 450 meters (1,155-1,485 ft).
Reaction to Competition
Redwood stands are dense. At 60 years, redwood may have a basal area of more than 126 m²/ha (550 ft²/acre) on the best sites (32). Heavy stocking is desirable because the relatively high tolerance permits land to support a large number of dominant and codominant trees per unit area.
Under some conditions, redwood can endure suppression almost indefinitely. A 25-cm (10-in) suppressed tree might be more than 100 years old. Small trees may be suppressed for more than 400 years but still maintain a remarkable capacity to accelerate growth rates when released if they have not been crowded too closely and are not injured seriously during logging or slash burning. Large trees also can accelerate growth when released from competition.
A study in extreme northwestern California indicated that a combination of wet soil and strong winds is necessary for significant windfall damage. Consequently, windfall is caused by only a few of the many winter storms. Storms that cause windfall come mainly from the south. Uprooting accounted for 80 percent of the redwood windfall in this study (7).
Life History and Behavior
Redwood female strobili become receptive and pollen is shed from late
November to early March. Female strobili start ripening in September of
the first year. Mature female strobili can be identified when their
color changes from green to greenish yellow. Seed dispersal begins in
late October, with most of the seeds being dispersed from November to
Studies in the past 10 years have improved the cutting procedure by hedging-a technique that seems to maintain the juvenility of the donor tree. A single seedling and its clonal descendants can produce about 1 million cuttings in 3 years by repeated hedging of seedlings and their descendants (29).
Modern methods of plant tissue culture also have propagated redwood successfully (3). Tissues from outstanding mature trees may be cultured in nutrient medium, becoming undifferentiated masses of cells or callus. In different nutrient media, fragments of the callus can be induced to differentiate into small plants. When these plants become large enough, juvenile cuttings can be taken from them (30). In France, scientists have found that shoots of redwood 10 to 20 mm (0.4 to 0.8 in) long are the best reactive material for producing explants, with fragments of the annual shoots being more reactive than the annual sprouts of 2-year-old shoots (13). Tissue cultured plantlets are generally twice the size of seedlings of the same age (2).
Redwood can sprout from stumps and root crowns anytime of the year. Numerous and vigorous sprouts originate from both dormant and adventitious buds within 2 to 3 weeks after logging. Sprouting capacity is related to variables associated with tree size or age. Stumps of small young trees sprout more readily than those of large old trees (35). Stumps often are circled by more than 100 sprouts. Many sprouts may be necessary to sustain a healthy stump-root system (4,15). Powers and Wiant (37) found that sprout vigor was related to sprout density. Sprout vigor was reduced at densities less than one sprout per 2 feet of stump circumference. Each sprout soon develops its own root system, and in a remarkably short time the dominant sprouts create circles of new trees around the old stumps.
Depending on the intensity of thinning or partial cutting in redwood, sprouts grow and develop successfully in openings (11,31). A recent study showed that more than 90 percent of all redwood stumps sprouted in a 40-year-old redwood stand thinned to 25, 50, and 75 percent of the initial basal area. Consequently, all thinned stands contained several hundred redwood sprout clumps per acre, and several thousand individual sprouts. The heavier the thinning, the more sprouts developed into vigorous young crop trees (31).
Sprouting by redwood is principally from root crowns, but sprouts sometimes grow from the sides and tops of stumps. These high sprouts are less desirable because they are mechanically weak and not as vigorous as root-crown sprouts. Sprouts originating from the sides and top of stumps often are destroyed by strong wind.
Sprouts are commonly about 60 to 90 cm (24 to 36 in) tall at the end of the first year but may be more than 1.8 m (6 ft) tall. In one instance, a fire killed all sprouts around a stump. About 300 new sprouts appeared within a few days, and at the end of one growing season many reached 2.1 m (7 ft). Sprouts grow more rapidly than seedlings and the initial impetus lasts many years. However, the best phenotypes at age 40 to 80 in stands originating from both sprouts and seedlings often are found to be of seedling origin (27).
Early estimates of stocking from root crown sprouts varied from 20 to 35 percent of full stocking. A later study showed that redwood sprouts on old growth cutover redwood land in Mendocino and Humboldt Counties, CA, provided only 8 percent of full stocking. This finding is low compared to more recent stand examinations where the majority of redwood stems in 163 moderately to fully stocked young growth stands originated from sprouts (33).
Redwood can also sprout along almost the entire length of its trunk. If the crown of a tree is destroyed by fire or mechanically damaged, or the stem is suddenly exposed to light, numerous dormant buds along the trunk are stimulated and produce new foliage. Most of the trunk is then covered by feathery foliage extending 0.6 to 0.9 m (2 to 3 ft) from the trunk. Eventually, normal crowns develop again.
New redwood seedlings require a greater supply of soil moisture for survival than that needed by seedlings of most associated trees (19). Late spring and early fall rains can be critical survival factors. Apparently, redwoods have no root hairs. Consequently, redwood roots do not seem to function efficiently in extracting soil moisture. This fact may limit natural distribution to sites where favorable water relations result from high rainfall, humid air, moist soil, or low summer temperatures, or from various combinations of these conditions. Redwood seedlings on fully exposed soil can withstand considerable surface heat if their roots have reached a permanent moisture supply. Otherwise, they die before soil surface temperatures reach 60° C (140° F). Redwood seedlings are extremely vulnerable to infection by damping-off and Botrytis fungi during their first year (22).
In its early stages, redwood grows rapidly in height. Seedlings often grow about 46 cm (18 in) in the first season and trees 4 to 10 years old sometimes grow 0.6 to 2.0 m (2 to 6.5 ft) in a year. In many instances, however, rapid height growth of trees that originate from seed does not commence until the trees are more than 10 years old.
Juvenile growth of redwood is best in full sunlight. Although redwood seedlings can endure heavy shade, growth there is slow. Photosynthetic capacity in redwood is remarkably high at low light intensities and keeps increasing as light intensity increases, much like more intolerant species. Redwood grew vigorously in much weaker light than 12 other tree species studied (38,39). For example, it increased its size 8.8 times in 10 percent of full sunlight in a 9-month period, more than twice the growth of any of the other species in the test. For appreciable growth, Engelmann spruce (Picea engelmannii) and Douglas-fir require twice as much light as redwood. Pine requires three to four times as much.
Radial growth of redwood in Mendocino County, CA, at points 6, 14, and 32 km (4, 9, and 20 mi) from the coast did not vary markedly in growth pattern. Radial growth began after mid-March, increased to a maximum in late May, and then declined at a fairly uniform rate to a minimum at the end of September. Radial growth was negligible from October 1 to March 15.
Seed Production and Dissemination
Trees with new, narrow crowns resulting from sprouting of dormant buds after fire has killed the crown produce few cones during the first 4 years after the fire. About one-half such narrow-crowned trees, locally called fire-columns, bear cones in the fifth year, and almost all produce cones by the seventh or eighth year.
The germination rate of redwood seeds is usually low. Poor germination often results from a low percentage of sound seeds (less than 15 percent) rather than from dormancy. When obviously defective seeds are removed, germination rarely is below 80 percent, and is sometimes 100 percent (27). Identification of defective seeds often is difficult, however, because many seeds appearing sound are filled with tannin. In one seed study, soundness varied significantly with seed size. Seeds passing 12, 10, and 8 mesh screens were 2, 8, and 15 percent sound, respectively. Seeds from seven populations were photographed by X-ray. The distribution in categories was as follows: seeds empty or tannin filled, 58 to 97 percent; seeds from embryos damaged by fungi, 0 to 11 percent; and sound seeds, 1 to 32 percent (38,39).
Although only scant evidence is recorded on storage of redwood seeds, they do not seem to store well. One seed lot was stored successfully for 3 years but lost its viability completely after 5 years (19).
Redwood cones dry readily under conditions of low humidity and quickly release their seeds with slight shaking. But because weather conditions at cone ripening in nature usually are unfavorable for rapid drying, seed dispersal may be spread over periods that vary considerably in length. Rains, however, may hasten seed dissemination. One observer found in many instances that redwood seeds remained in the open cones until a drenching rain dissolved the tannic crystals in the cones (38,39). Seed dissemination during the winter months seems characteristic of redwood in the northern stands. More than four-fifths of the sound seeds in one study were shed during December and January.
Redwood seeds are small and light, number about 265,000/kg (120,000/lb), but lack efficient wings to slow them in falling (10). They fall at rates between 1.5 and 6.2 m/s (4.9 and 20.5 ft/s), averaging 2.6 m/s (8.6 ft/s). These rates are faster than for most other wind-disseminated forest seeds and limit seed dispersal considerably.
Timbered edges of clearcut units have effective seeding distances of only 61 m (200 ft) uphill and 122 m (400 ft) downhill under average redwood stand conditions. A recent study in Del Norte County, CA, showed that the largest clearcut units should not be more than 12 to 16 ha (30 to 40 acres) if regeneration will be completed by natural seeding (38,39). No silvicultural reasons exist for restricting the size of clearcuts, if areas are regenerated by artificial methods. Maximum size of clearcuttings is specified in Forest Practice Rules, based on erosion hazard, or other criteria.
Flowering and Fruiting
Redwood cones are terminal and are 13 to 29 mm (0.5 to 1.1 in) long. They mature in autumn of the first year after flowering and are open from early September until late December. Although cones persist for several months, they open and shed seeds soon after ripening.
Growth and Yield
Redwood probably is best known for its great size, although the average redwood is smaller than commonly believed. Trees larger than 30 cm (12 in) in d.b.h. on a 12-ha (30-acre) old-growth tract in Humboldt County, CA, fell approximately into these divisions: 30 to 77 cm (12 to 30 in) in d.b.h., 50 percent; 78 to 153 cm (31 to 60 in), 32 percent; 155 cm (61 in) and larger, 18 percent. Redwoods 366 to 488 cm. (144 to 192 in) in d.b.h., found scattered over the entire range, are considered large. Trees 610 cm (240 in) or more in diameter at a point 1.5 m (5 ft) above the ground are rare.
Redwoods more than 61 m (200 ft) tall are common, and many trees growing on riverside benches, where soils are deep and moist, are taller than 91 m (300 ft). The tallest measured redwood was 112.1 m (367.8 ft) in 1964 (50).
Large trees and dense stocking combine to produce high yields. More than 81 percent of the commercial redwood forest land is classified as highly productive, and only 2 percent is poor for growing trees. Flats along rivers have yielded approximately 10,500 to 14,000 m³/ha (about 750,000 to 1,000,000 fbm/acre) in scaled logs. Harvest cuttings in Del Norte County, CA, on units of 5.3 ha (13 acres) and larger, produced gross volumes ranging from 1330 to 3921 m³/ha (95,000 to 280,000 fbm/acre, Scribner).
Biomass accumulates to record levels. A redwood stand in Humboldt State Park in California provides the greatest biomass ever recorded, with a stem biomass of 3461 t/ha (1,544 tons/acre) (20).
Economical conversion of old-growth redwood to young managed stands by shelterwood or selection cutting is difficult because net growth is negative during the decade after logging. Windthrow, slow growth of residual trees, and damage to established reproduction when residual trees are removed contribute to economic losses. Considering effect on growth, small clearcuttings seem to be a good method for converting old-growth redwood to young managed stands (9).
Young-growth redwood is often nearly as spectacular in size and yield as old growth. Dominant young-growth trees on good sites are 30.5 to 45.7 m (100 to 150 ft) tall at 50 years, and 50.3 to 67.1 m (165 to 220 ft) at 100 years. Height growth is most rapid up to the 35th year. On the best sites, however, height growth continues to be rapid well past 100 years (24,33).
Diameter growth of individual young trees can be rapid or extremely slow. In dense stands where competition is severe, annual diameter increment is commonly less than 1 mm (0.03 in). Occasionally, 40 or more rings per centimeter (more than 100/in) can be counted. At the other extreme, diameter growth sometimes exceeds 2.5 cm (1 in) a year. One redwood growing with little competition was 213 cm (84 in) in d.b.h. when 108 years old.
The yield of young-growth redwood stands at 100 years is expected to range from 742 m³/ha (10,600 ft³/acre) on low sites to 3576 m³/ha (51,080 ft³/acre) on high sites (32). The same stands yield 781 to 4998 m³/ha (55,760 to 357,000 fbm/acre International quarter-inch rule), and yields of more than 2800 m³/ha (about 200,000 fbm/acre International quarter-inch rule) are common in young-growth redwood stands. At earlier ages, however, the greatest yields are in stands that contain a mixture of redwood and Douglas-fir (25).
Natural pruning in young redwood stands often is not good. Although live crowns may be limited to the upper third of the trunk, dead limbs are persistent. Branch stubs, although decayed, may remain more than 50 years. In old trees, some branch stubs have affected the quality of the timber over a 200-year period. Trees in the intermediate crown class, however, often prune well naturally, and some trees in a heavily stocked stand have clean trunks for 23 to 30 m (75 to 100 ft) at 85 years.
Molecular Biology and Genetics
Races of redwood are not known, but the following cultivars (cultivated varieties) have been recognized (16):
cv. 'Adpressa' Tips of shoots creamy white. Awl-like leaves.
cv. 'Glauca' Leaves 6 mm (0.25 in) long, glaucous, bluish.
cv. 'Nana Pendula' Leaves glaucous, branches pendulous.
cv. 'Pendula' Branches pendulous.
cv. 'Prostrata' Prostrate at first; leaves green, glaucous beneath.
Four varieties of redwood now available in nurseries show a range of growth habits, texture, color, and form. They are named Aptos Blue, Los Altos, Soquel, and Santa Cruz (6).
An uncommon form of redwood, the albino redwood, has been described in a few locations within the redwood region (17). These albinos result from a genetic disorder and exist by attachment to a normal green tree, generally at the roots. The tallest albino observed was 19.8 m (65 ft) tall. Albinism is often a useful trait in genetics research to determine mutation rate, and for other purposes.
Preliminary results from studies of self and related outcross families indicate that, compared with outcrosses, selfing produced no additional cone abortion or variable effects on germination. Under stress conditions in nurseries and outplantings, some inbreeding depression becomes evident, and restricting inbreeding in redwood seed-orchards seems prudent (30).
The tissue culture techniques described earlier also allow genetic manipulation of redwood at the cellular level. Possibilities being explored include the production of di-haploid redwood from female gametophyte cultures (2).
Barcode data: Sequoia sempervirens
Statistics of barcoding coverage: Sequoia sempervirens
Public Records: 3
Specimens with Barcodes: 4
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
According to forestry estimates in Burns and Honkala (1990) there remained by the end of the twentieth century a total of 260,200 ha of commercial forest with more than 50% redwood stocking, while a further 80,940 ha was old-growth redwood mostly within protected areas. If the latter forests were also 50% redwood, this would translate in a minimal area of occupancy (AOO) of 1,400 km, to which would have to be added an unknown figure for redwoods occurring as a minor component. The AOO is thus likely to fall below 2,000 km, the threshold for Vulnerable.
Past decline is, as always, difficult to estimate as there were no accurate estimates of an AOO when logging operations began. It is almost certainly in excess of 50% over three generations, which in the case of this very long-lived species takes us back to the period before Europeans and their impact on the forest arrived in northern California.
Continuing decline is inferred from the fact that the proportion of redwood in commercially exploited forests containing this species is still declining, due to deliberate or accidental replacement by more competitive species in the early phases of succession after clear-felling, especially Pseudotsuga menziesii. Under the A2 criterion this species should therefore be listed as Endangered.
- 2006Vulnerable (VU)
- 1998Rare (R)
- 1998Lower Risk/conservation dependent (LR/cd)
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Reasons: Abundant, even dominant, in a substantial but not large geographic range (Pacific coast of northern and central California, and adjacent southwestern Oregon). Mature trees in areas not protected as conservation lands subject to substantial demand for timber.
Global Short Term Trend: Relatively stable (=10% change)
Comments: In the short term view, redwoods have not declined much at all and are considered more or less stable.
Global Long Term Trend: Decline of 30-50%
Comments: Old growth redwood forests have mostly been cut for timber, but many of the better, remaining stands are now protected in parks and preserves. Substantial cutting of redwood, including second-growth, continues on private forest lands. Thus mature trees are far scarcer than 150 years ago but young trees are still quite numerous, and found nearly throughout the historical range of the species.
Comments: Demand for timber on remaining private forest lands remains strong, with the wood having unique properties that make substitution difficult. Climate change is changing the environment of the north coast to be less foggy, and perhaps more prone to catastrophic fires. However, there is some evidence that there is increased tree growth (from core studies) in the past few decades, due to increased precipitation, which is also attributed to climate change.
Wildlife: The marbled murrelet is dependent on old-growth redwood
forests for nesting habitat. This bird is listed as endangered in
California and is under consideration for federal protection as a
threatened species in California, Oregon, and Washington .
Old-growth redwood forests of northern California also provide critical
habitat for the federally endangered northern spotted owl .
Black-tailed deer numbers increase after clearcutting in the redwood
forest type as a result of the sudden increase in available understory
forage. After canopy closure (20 to 30 years), black-tailed deer
numbers decrease rapidly .
Years after clearcut Number of deer
0 to 5 43
5 to 10 142
10 to 15 21
15 to 20 21
20 to 25 8
25 to 30 8
Competition: Evergreen hardwoods are strong competitors in the redwood
forest type. Tanoak (Lithocarpus densiflorus) and Pacific madrone
(Arbutus menziesii) often sprout when cut, and reoccupy the site
before redwood. These competitors can be controlled by trunk injections
of triclopyr (Garlon 3A), with two to three treatments over a 4- to
5-year period giving the best results. Foliar spraying with triclopyr
can also control hardwoods but has adverse effects on redwood .
Mulching and the use of ground covers increase survival of planted
seedlings by reducing water evaporation and reducing competition from
shrubs . Seedling survival can also be enhanced with the use of
Damage: Damaging agents include insects, branch canker (Coryneum spp.),
and heart rots (Poria sequoiae, P. albipellucida). The insects
associated with redwood cause no significant damage, but the branch
canker girdles stems and branches, which can be especially harmful in
plantations. Heart rots cause extensive cull in the redwood forest type
Wood rats girdle and strip the bark of redwood seedlings, and can
seriously limit redwood regeneration. Where this is a problem, site
preparation should include destroying wood rat nesting areas .
Redwood is susceptible to damage from soil compaction in areas of heavy
foot traffic .
Silviculture: The preferred silvicultural system for harvesting
redwoods is small clearcuts (30 to 40 acres) [10,41]. Boe  provides
information on the three silvicultural systems used in the redwood
forest type: clearcut, shelterwood, and selection cut.
Other: Namkoong and Roberds  developed an extinction model for
redwood. Their findings reveal there is a small probability of
extinction due to natural processes, which can easily be circumvented by
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
In a large cutover area acquired by Redwood National Park, both
plantings and natural colonization of redwood on outsloped (recontoured
into the hillside) logging roads were used with good success. This
treatment curtailed erosion in the park by an estimated 6.6 million
cubic feet (0.2 mil m3) .
Redwood was one of a number of native species used successfully to
reclaim a riparian ecosystem in a city park in Berkeley; redwoods on the
site had a high survival rate .
Redwood can be propagated via seed or cuttings. Seeds should be sown
from December to April. If planting with a seed drill, the recommended
depth is 0.125 inch (0.32 cm), with a seeding rate that will yield 30
seedlings per square foot (333 seedlings/sq m) . Cuttings from 2- to
3-year-old seedlings produce the highest percentage of rooted cuttings
(up to 90 percent); cuttings from older trees are more difficult to root
[36,40]. Hedging (close-cropping) can maintain the rooting capabilities
of the donor tree. By repeated hedging a single donor seedling and its
clones can produce a million cuttings in 3 years . Redwood can also
be successfully propagated in plant tissue culture. The callus can be
induced to generate cultured plantlets. The cultured plantlets are
usually twice the size of seedlings the same age .
Millar and Libby  have developed guidelines for redwood seed
collection and for the use of redwood in the restoration of disturbed
Redwood forests provide hiding and thermal cover for Roosevelt elk,
black-tailed deer, and a variety of small mammals [24,45,48,50].
The pileated woodpecker generally selects broken tree tops or snags with
rot for nesting cover. The softness of redwood, however, allows the
pileated woodpecker to use green trees of adequate size. In one study
only half the nests of pileated woodpeckers were in redwoods that had
broken tops with rot, while the other half were in sound green trees
with no sign of decay in the excavation chips .
In California, the state-endangered marbled murrelet nests exclusively
in coastal old-growth redwood forests .
Wood Products Value
wood is soft, weak, easily split, and very resistant to decay
[38,40,44]. The clear wood is used for dimension stock and shingles
. Redwood burls are used in the production of table tops, veneers,
and turned goods .
Other uses and values
ornamentals due to their reduced size . Redwood has been planted in
New Zealand, Australia, and Europe .
Native Americans used redwood in the construction of canoes and as grave
Importance to Livestock and Wildlife
reptiles, and amphibians [7,45,48]. Remnant old-growth redwood stands
provide habitat for the federally threatened spotted owl and the
California-endangered marbled murrelet [1,46].
In settlement times fire scar cavities at the base of larger redwood
boles were used as goose pens; hence the name "goosepens" has been used
to denote fire scar cavities .
A prominent special feature of the redwood is its production of burls from which beautifully figured table tops, veneers, bowls, and other turned products are cut. These burls are found on any part of the trunk and in sizes varying from an inch to many feet in diameter. Their cause is unknown. Small burls containing hundreds of dormant buds often are cut and placed in shallow containers, kept moist, and allowed to sprout. These live burls serve as attractive house plants.
Another feature of redwood is its extremely tough and fibrous bark. The bark must be removed before logs reach the head saws so that sawing uniform lumber will be possible. The bark is used as hog fuel, insulation, or garden mulch.
Sequoia sempervirens / / is the sole living species of the genus Sequoia in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal redwood and California redwood. It is an evergreen, long-lived, monoecious tree living 1,200–1,800 years or more. This species includes the tallest living trees on Earth, reaching up to 379 feet (115.5 m) in height (without the roots) and up to 27.4 feet (8.4 m) in diameter at breast height / dbh. These trees are also among the oldest living things on Earth. Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated 2,100,000 acres (8,500 km2) along much of coastal California (excluding southern California where rainfall is not sufficient) and the southwestern corner of coastal Oregon within the United States. An estimated 95% or more of the original old-growth redwood trees have been cut down.
The name sequoia sometimes refers to the subfamily Sequoioideae, which includes S. sempervirens along with Sequoiadendron (giant sequoia) and Metasequoia (dawn redwood). On its own, the term redwood usually refers to the coast redwood, which is covered in this article, and not to the other two species.
Scottish botanist David Don described the redwood as the evergreen taxodium (Taxodium sempervirens) in his colleague Aylmer Bourke Lambert's 1824 work A description of the genus Pinus. Austrian botanist Stephan Endlicher erected the genus Sequoia in his 1847 work Synopsis coniferarum, giving the redwood its current binomial name of Sequoia sempervirens. The redwood is one of three living species, each in its own genus, in the subfamily Sequoioideae. Molecular studies have shown the three to be each other's closest relatives, generally with the redwood and giant sequoia (Sequoiadendron giganteum) as each other's closest relatives. However Yang and colleagues in 2010 queried the polyploid state of the redwood and speculate that it may have arisen as an ancient hybrid between ancestors of the giant sequoia and dawn redwood (Metasequoia). Using two different single copy nuclear genes, LFY and NLY, to generate phylogenetic trees, they found that Sequoia was clustered with Metasequoia in the tree generated using the LFY gene, but with Sequoiadendron in the tree generated with the NLY gene. Further analysis strongly supported the hypothesis that Sequoia was the result of a hybridization event involving Metasequoia and Sequoiadendron. Thus, Yang and colleagues hypothesize that the inconsistent relationships among Metasequoia, Sequoia, and Sequoiadendron could be a sign of reticulate evolution (in which two species hybridize and give rise to a third) among the three genera. However, the long evolutionary history of the three genera (the earliest fossil remains being from the Jurassic) make resolving the specifics of when and how Sequoia originated once and for all a difficult matter—especially since it in part depends on an incomplete fossil record.
The coast redwood can reach 110 m (379 ft) tall with a trunk diameter of 9 m (30 ft). It has a conical crown, with horizontal to slightly drooping branches. The bark can be very thick, up to 1 foot (35 cm), and quite soft and fibrous, with a bright red-brown color when freshly exposed (hence the name redwood), weathering darker. The root system is composed of shallow, wide-spreading lateral roots.
The leaves are variable, being 15–25 mm (0.59–0.98 in) long and flat on young trees and shaded shoots in the lower crown of old trees. On the other hand, they are scale-like, 5–10 mm (0.20–0.39 in) long on shoots in full sun in the upper crown of older trees, with a full range of transition between the two extremes. They are dark green above and have two blue-white stomatal bands below. Leaf arrangement is spiral, but the larger shade leaves are twisted at the base to lie in a flat plane for maximum light capture.
The species is monoecious, with pollen and seed cones on the same plant. The seed cones are ovoid, 15–32 millimetres (0.59–1.26 in) long, with 15–25 spirally arranged scales; pollination is in late winter with maturation about 8–9 months after. Each cone scale bears three to seven seeds, each seed 3–4 millimetres (0.12–0.16 in) long and 0.5 millimetres (0.020 in) broad, with two wings 1 millimetre (0.039 in) wide. The seeds are released when the cone scales dry out and open at maturity. The pollen cones are ovular and 4–6 millimetres (0.16–0.24 in) long.
Its genetic makeup is unusual among conifers, being a hexaploid (6n) and possibly allopolyploid (AAAABB). Both the mitochondrial and chloroplast genomes of the redwood are paternally inherited.
Distribution and habitat
Coast redwoods occupy a narrow strip of land approximately 750 km (470 mi) in length and 5–47 mi (8–75 km) in width along the Pacific coast of North America; the most southerly grove is in Monterey County, California, and the most northerly groves are in extreme southwestern Oregon. The prevailing elevation range is 98–2,460 feet (30–750 m) above sea level, occasionally down to 0 and up to 3,000 ft (about 920 meters). They usually grow in the mountains where precipitation from the incoming moisture off the ocean is greater. The tallest and oldest trees are found in deep valleys and gullies, where year-round streams can flow, and fog drip is regular. The trees above the fog layer, above about 2,296 feet (700 m), are shorter and smaller due to the drier, windier, and colder conditions. In addition, Douglas-fir, pine, and tanoak often crowd out redwoods at these elevations. Few redwoods grow close to the ocean, due to intense salt spray, sand, and wind. Coalescence of coastal fog accounts for a considerable part of the trees' water needs.
The northern boundary of its range is marked by two groves on the Chetco River on the western fringe of the Klamath Mountains, 15 mi (24 km) north of the California-Oregon border. The largest (and tallest) populations are in Redwood National and State Parks (Del Norte and Humboldt Counties) and Humboldt Redwoods State Park (Humboldt County, California), with the majority located in the much larger Humboldt County. The southern boundary of its range is the Los Padres National Forest's Silver Peak Wilderness in the Santa Lucia Mountains of the Big Sur area of Monterey County, California. The southernmost grove is in the Southern Redwood Botanical Area, just north of the national forest's Salmon Creek trailhead.
The prehistoric fossil range of the genus is considerably greater, with a subcosmopolitan distribution including Europe and Asia until about 5 million years ago. During the cooler and wetter ice age, redwood trees grew as far south as the Los Angeles area (coast redwood bark found in subway excavations and at La Brea tar pits).
This native area provides a unique environment with heavy seasonal rains up to 100 inches (2,500 mm) annually. Cool coastal air and fog drip keep this forest consistently damp year round. Several factors, including the heavy rainfall, create a soil with fewer nutrients than the trees need, causing them to depend heavily on the entire biotic community of the forest, especially complete recycling of the trees when dead. This forest community includes coast Douglas-fir, Pacific madrone, tanoak, western hemlock, and other trees, along with a wide variety of ferns, mosses, mushrooms, and redwood sorrel. Redwood forests provide habitat for a variety of amphibians, bird, mammals, and reptiles. Old-growth redwood stands provide habitat for the federally threatened spotted owl and the California-endangered marbled murrelet.
The thick, tannin-rich bark, combined with foliage starting high above the ground provides good protection from both fire and insect damage, contributing to the coast redwood's longevity. The oldest known specimen is about 2,200 years old; many others in the wild exceed 600 years. The numerous claims of older trees are incorrect. Because of their seemingly timeless lifespans, coast redwoods were deemed the "everlasting redwood" at the turn of the century; in Latin, sempervirens means "ever green" or "everlasting". Redwood must endure fire to attain such great ages, so this species has many fire-resistant characteristics. In addition, fires appear to actually benefit redwoods by causing substantial mortality in competing species while having only minor effects on redwood. A study published in 2010, the first to compare postwildfire survival and regeneration of redwood and associated species, concluded fires of all severity increase the relative abundance of redwood and higher-severity fires provide the greatest benefit.
The height of S. sempervirens is closely tied to fog availability, as taller trees become less frequent as fog becomes less frequent. As S. sempervirens’ height increases, transporting water via water potential to the leaves becomes increasingly more difficult due to gravity. Despite the high rainfall that the region receives (up to 100 cm), the leaves in the upper canopy are stressed for water. The water stress is believed to cause the morphological changes in the leaves, stimulating reduced leaf length and increased leaf succulence. Water stress is reduced in the upper canopy by the leaves taking in fog from the surrounding air through the epidermal tissue, bypassing the xylem. The uptake of water through the leaves causes the xylem flow to reverse, which repairs and reduces the severity of cavitations.
Coast redwood reproduces both sexually by seed and asexually by sprouting of buds, layering, or lignotubers. Seed production begins at 10–15 years of age, and large seed crops occur frequently, but viability of the seed is low, typically well below 15%. The low viability may discourage seed predators, which do not want to waste time sorting chaff (empty seeds) from edible seeds. The winged seeds are small and light, weighing 3.3–5.0 mg (200-300 seeds/g; 5,600-8,500/ounce). The wings are not effective for wide dispersal, and seeds are dispersed by wind an average of only 60–120 m (200–400 ft) from the parent tree. Growth of seedlings is very fast, with young trees known to reach 20 m (65 ft) tall in 20 years.
Coast redwoods can also reproduce asexually by layering or sprouting from the root crown, stump, or even fallen branches; if a tree falls over, it will regenerate a row of new trees along the trunk, so many trees naturally grow in a straight line. Sprouts originate from dormant or adventitious buds at or under the surface of the bark. The dormant sprouts are stimulated when the main adult stem gets damaged or starts to die. Many sprouts spontaneously erupt and develop around the circumference of the tree trunk. Within a short period after sprouting, each sprout will develop its own root system, with the dominant sprouts forming a ring of trees around the parent root crown or stump. This ring of trees is called a "fairy ring". Sprouts can achieve heights of 2.3 m (8 ft) in a single growing season.
Redwoods may also reproduce using burls. A burl is a woody lignotuber that commonly appears on a redwood tree below the soil line, though usually within 3 metres (10 ft) in depth from the soil surface. Burls are capable of sprouting into new trees when detached from the parent tree, though exactly how this happens is yet to be studied. Shoot clones commonly sprout from burls and are often turned into decorative hedges when found in suburbia.
The species is very tolerant of flooding and flood deposits, the roots rapidly growing into thick silt deposits after floods.
Cultivation and uses
Coast redwood is one of the most valuable timber species in the lumbering industry. In California, 899,000 acres (3,640 km2) of redwood forest are logged, virtually all of it second growth. Though many entities have existed in the cutting and management of redwoods, perhaps none have had a more storied role than the Pacific Lumber Company (1863–2008) of Humboldt County, California, where it owned and managed over 200,000 acres (810 km2) of forests, primarily redwood. Coast redwood lumber is highly valued for its beauty, light weight, and resistance to decay. Its lack of resin makes it resistant to fire.
P.H. Shaughnessy, Chief Engineer of the San Francisco Fire Department wrote,
- "In the recent great fire of San Francisco, that began April 18th, 1906, we succeeded in finally stopping it in nearly all directions where the unburned buildings were almost entirely of frame construction, and if the exterior finish of these buildings had not been of redwood lumber, I am satisfied that the area of the burned district would have been greatly extended."
Because of its impressive resistance to decay, redwood was extensively used for railroad ties and trestles throughout California. Many of the old ties have been recycled for use in gardens as borders, steps, house beams, etc. Redwood burls are used in the production of table tops, veneers, and turned goods.
The coast redwood is naturalized in New Zealand, notably at Whakarewarewa Forest, Rotorua. Redwood has been grown in New Zealand plantations for over 100 years, and those planted in New Zealand have higher growth rates than those in California, mainly due to even rainfall distribution through the year. Other areas of successful cultivation outside of the native range include Great Britain, Italy, Portugal, the Queen Charlotte Islands, middle elevations of Hawaii, Hogsback in South Africa, a small area in central Mexico (Jilotepec), and the southeastern United States from eastern Texas to Maryland. It also does well in the Pacific Northwest (Oregon, Washington, and British Columbia), far north of its northernmost native range in southwestern Oregon. Coast redwood trees were used in a display at Rockefeller Center and then given to Longhouse Reserve in East Hampton, Long Island, New York, and these have now been living there for over twenty years and have survived at 2 °F (-17 °C).
This fast-growing tree can be grown as an ornamental specimen in those large parks and gardens that can accommodate its massive size. It has gained the Royal Horticultural Society's Award of Garden Merit.
Trees over 200 feet (60 m) are common, and many are over 300 feet (90 m). The current tallest tree is the Hyperion tree, measuring 379.3 feet (115.61 m). The tree was discovered in Redwood National Park during the summer of 2006 by Chris Atkins and Michael Taylor, and is thought to be the world's tallest living organism. The previous record holder was the Stratosphere Giant in Humboldt Redwoods State Park at 370.2 feet (112.84 m) (as measured in 2004). Until it fell in March 1991, the "Dyerville Giant" was the record holder. It, too, stood in Humboldt Redwoods State Park and was 372 feet (113.4 m) high and estimated to be 1,600 years old. This huge fallen giant has been preserved in the park to allow visitors to walk the trail along its trunk.
Forty-one measured living trees are more than 360 feet (109.7 m) tall, and 178 are more than 350 feet (106.7 m) tall. Preliminary LiDAR data indicate hundreds of additional trees are in excess of 350 feet (106.7 m), which were previously unknown. A tree claimed to be 380 feet (115.8 m) was cut down in 1914, and another claimed to be 424 feet (129.2 m) was felled in November 1886 by the Elk River Mill and Lumber Co. in Humboldt County, California, yielding 79,736 marketable board feet from 21 cuts. However, these accounts and many others must be viewed with skepticism as there is limited evidence to corroborate the measurements, and exaggerated claims were not uncommon in the lumber industry.
Although coast redwoods are the tallest known living trees, historical accounts of taller Australian mountain ash and Douglas fir trees exist – sometimes exceeding 400 feet (122 m). Like most of the redwoods, these giants fell victim to widespread commercial logging in the 19th and 20th centuries and the tallest existing specimens of each are much shorter than the tallest redwoods. A Douglas fir that fell in 1924 in Mineral, Washington was determined to have been about 1020 years old, 393 feet (119.8 m) high, and 15.4 feet (4.69 m) in diameter by two highly respected forest scientists. Another Douglas fir cut down in 1902 at Lynn Valley on the north shore of the city of Vancouver, British Columbia was reported to have measured 415 feet (126.5 m) in height and 14.3 feet (4.36 m) in diameter, although these measurements are somewhat less certain. Other accounts claim felled Douglas firs were as tall as 465 feet (141.7 m).
These accounts aside, fairly solid evidence indicates that coast redwoods were the world's largest trees before logging, with numerous historical specimens reportedly over 400 feet (122 m). The theoretical maximum potential height of coast redwoods is thought to be limited to between 400 and 425 feet (121.9 and 129.5 m) as capillary action is insufficient to transport water to leaves beyond this range. Further studies have indicated this cap is eased by fog, which is prevalent in these tree's natural environment.
The largest known living coast redwood is the "Lost Monarch", with an estimated volume of 42,500 cubic feet (1,200 m3); it is 321 feet (97.8 m) tall, with a diameter of 26 feet (7.9 m) at 4.5 feet above ground level. It is located in the Grove of Titans. Among current living trees, only six known giant sequoias are larger; these are shorter, but have thicker trunks overall, giving the largest giant sequoia, General Sherman, a volume of 52,500 cubic feet (1,490 m3), making it the world's current largest known tree.
About 230 albino redwoods (mutant individuals that cannot manufacture chlorophyll) are known to exist, reaching heights of up to 20 metres (66 ft). These trees survive as parasites, obtaining food by grafting their root systems with those of normal trees. While similar mutations occur sporadically in other conifers, no cases are known of such individuals surviving to maturity in any other conifer species.
Some volumes shown are based on additional stems. Some extra stems have a point of origin above ground off the main trunk, but other like basal stems can emerge from soil level. For Lost Monarch, some writers included 6,000 cu. ft. of large basal sprouts from soil level, referred to by Dr. Robert Van Pelt as "separate trees". The largest single coast redwood tree trunk is believed to be Number 2 (1b), because its volume shown is main bole only (volume of Melkor and Illuvatar are based on extra reiterated stems). At least one tree will be on a Big Tree Registry, ranked by points; 1 point for each foot of height, 1 point for each inch of circumference, and 1 point for every 4 ft. of crown width. The 11 largest known coast redwoods by total wood volume in the main trunk and stems combined, as of 2009 - 2014 data, are:
|Rank||Name||Volume||Height||Diameter||Location||Volume based on single bole, fused trunks, or multi-stem|
|1||Melkor, aka Fusion Giant||39,100 cubic feet (1,110 m3)||349 feet (106.4 m)||22.4 feet (6.83 m)||RNP||Fused. Total volume also includes all reiterations.|
|2 (1b)||Name Unknown ||38,299 cubic feet (1,084.5 m3)||over 300 ft.||over 20 ft.||RNSP||Single. Reiterations not added. Volume larger. 38,299 is only main bole. Confirmed as largest main bole known for the species. Retains 1296 points, surpassing the California Big Tree registry's listed champion.|
|3||Iluvatar||37,500 cubic feet (1,060 m3)||300 feet (91.4 m)||20.5 feet (6.25 m)||PCRSP||Single. Significant volume in reiterated stems |
|4||Del Norte Titan||37,200 cubic feet (1,050 m3)||307 feet (93.6 m)||23.7 feet (7.22 m)||JSRSP||Single. Significant volume in reiterated stems  In the past, often referred to as the largest single-stem coast redwood (at one time)|
|5||Lost Monarch||36,500 cubic feet (1,030 m3)||321 feet (97.8 m)||26.0 feet (7.92 m)||JSRSP||Multi-stem. 6,000 cu. ft. sprout (tree) from root soil.  Main bole 36,500 cu. ft.. Some sources add stem volumes for 42,500 cu. ft.. Listed at American Forests and California Big Tree Registries as species champion with 1291 points.|
|6||El Viejo Del Norte||35,400 cubic feet (1,000 m3)||324 feet (98.8 m)||23.0 feet (7.01 m)||JSRSP||Single.|
|7||Howland Hill Giant||33,580 cubic feet (951 m3)||330 feet (100.6 m)||19.8 feet (6.04 m)||JSRSP||Single. All volume in main bole. A circulated description "stovepipe" refers to slow trunk taper, not a hollow in the bole. |
|8||Sir Isaac Newton||33,192 cubic feet (939.9 m3)||299 feet (91.1 m)||22.5 feet (6.86 m)||PCRSP||Single. Huge burl adds small percentage|
|9||Terex Titan||32,384 cubic feet (917.0 m3)||270 feet (82.3 m)||21.3 feet (6.49 m)||PCRSP||Single. Includes small cave in base|
|10||Adventure Tree||32,140 cubic feet (910 m3)||334 feet (101.8 m)||16.5 feet (5.03 m)||PCRSP||Single. Includes 4 small caves in upper trunk|
|11||Bull Creek Giant||31,144 cubic feet (881.9 m3)||339 feet (103.3 m)||22.3 feet (6.80 m)||HRSP||Single. All volume in main bole |
Diameter stated is as measured at 1.4 meters (~4.5 feet) above average ground level (diameter at breast height). Details of the precise locations of all above trees have not been announced to the general public for fear of publicity causing damage to the trees and the surrounding ecology. The order of largest and tallest can change at any time due to new discoveries, loss of stem and foliage, growth, and new measurements. One of the better known internet databases for large conifers is the Gymnosperm Database, but its data can be different from other resources due to differences in standards.
Trees over 112 m (367 ft), as of 2010:. New data is likely to be published without corresponding names, and the actual tallest trees may remain unknown post-2010, indefinitely. Some changes happened, but the specific change in order is not available.
|1||Hyperion||379.3 feet (115.61 m)||15.2 feet (4.63 m)||RNSP|
|2||Helios||375.9 feet (114.57 m)||16.0 feet (4.88 m)||RNSP|
|3||Icarus||371.2 feet (113.14 m)||12.4 feet (3.78 m)||RNSP|
|4||Stratosphere Giant||371.1 feet (113.11 m)||17.0 feet (5.18 m)||HRSP|
|5||National Geographic||369.9 feet (112.75 m)||14.4 feet (4.39 m)||RNSP|
|6||Orion||369.5 feet (112.62 m)||13.7 feet (4.18 m)||RNSP|
|7||Lauralyn||369.5 feet (112.62 m)||14.9 feet (4.54 m)||HRSP|
|8||Paradox||369.3 feet (112.56 m)||12.8 feet (3.90 m)||HRSP|
|9||Mendocino||368.1 feet (112.20 m)||10.1 feet (3.08 m)||MWSR|
|10||Apex||367.4 feet (111.98 m)||11.1 feet (3.38 m)||HRSP|
Diameter stated is as measured at 1.4 meters (~4.5 feet) above average ground level (at breast height). Details of the precise locations of all above trees have not been announced to the general public for fear of publicity causing damage to the trees and the surrounding ecology. The tallest coast redwood easily accessible to the public is the Founders Tree in Humboldt Redwoods State Park, standing over 346 feet tall (a taller coast redwood is accessible to the public in Tall Trees Grove of Redwood National Park).
Other notable examples
- The Navigation (or Blossom Rock) trees were two especially tall Sequoia located in the Oakland Hills used as a navigation aid by sailors to avoid the treacherous Blossom Rock near Yerba Buena Island.
- One of the largest redwood stumps ever found (31' in diameter) is in the Oakland Hills in the Roberts Regional Recreation Area section of Redwood Regional Park. Only a single old growth redwood (the Grandfather) remains from the original forest.
- Bank Hall Gardens
- Bury Me in Redwood Country
- Leighton Hall, Powys
- List of largest giant sequoias
- Northern California coastal forests (WWF ecoregion)
- Pacific temperate rain forest (WWF ecoregion)
- Redwood (color)
- Save-the-Redwoods League
- List of superlative trees
- Farjon, A. & Schmid, R. (2011). "Sequoia sempervirens". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 2 January 2014.
- Sunset Western Garden Book, 1995:606–607
"sempervirent". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005.
- "BSBI List 2007" (xls). Botanical Society of Britain and Ireland. Retrieved 2014-10-17.
- The related Sequoiadendron giganteum is commonly referred to as "giant redwood".
- "Sequoia gigantea is of an ancient and distinguished family". Nps.gov. 2007-02-02. Retrieved 2012-08-07.
- "Coast Redwood Discovery. Sequoia sempervirens.". mdvaden.com.
- Kelly, D. and G. Braasch. 1988. Secrets of the old growth forest. Gibbs Smith, Layton, Utah: 1–99.
- Don, David (1824). Lambert, Aylmer Bourke, ed. A description of the genus Pinus :illustrated with figures, directions relative to the cultivation, and remarks on the uses of the several species 2. London, United Kingdom: J. White. p. 24.
- Endlicher, Stephan (1847). Synopsis Coniferarum. St. Gallen: Scheitlin & Zollikofer.
- Yang, Z.Y.; Ran, J.H.; Wang, X.Q. (2012). "Three Genome-based Phylogeny of Cupressaceae s.l: Further Evidence for the Evolution of Gymnosperms and Southern Hemisphere Biogeography". Molecular Phylogenetics and Evolution 64. doi:10.1016/j.ympev.2012.05.004.
- "Sequoia sempervirens (D. Don) Endlicher". www.efloras.org: Flora of North America. Retrieved 1 February 2015.
- Ahuja, MR; Neale, DB (2002). "Origins of Polyploidy in Coast Redwood (Sequoia sempervirens) and Relationship of Coast Redwood to other Genera of Taxodiaceae". Silvae Genetica 51 (2–3): 93–100.
- Neale, DB; Marshall, KA; Sederoff, RR (1989). "Chloroplast and Mitochondrial DNA are Paternally Inherited in Sequoia sempervirens". Proceedings of the National Academy of Sciences 86 (23): 9347–9. Bibcode:1989PNAS...86.9347N. doi:10.1073/pnas.86.23.9347. PMC 298492. PMID 16594091.
- Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4.
- "Redwood fog drip". Bio.net. 1998-12-02. Retrieved 2012-08-07.
- "Los Padres National Forest". Redwoodhikes.com. Retrieved 2012-08-07.
- Earle, CJ (2011). "Sequoia sempervirens". The Gymnosperm Database. Olympia, Washington: self-published. Retrieved 2011-08-13.
- Ramage, B.S.; OʼHara, K.L.; Caldwell, B.T. (2010). "The role of fire in the competitive dynamics of coast redwood forests". Ecosphere 1 (6). article 20. doi:10.1890/ES10-00134.1.
- Harris, S. A. (1989). "Relationship of convection fog to characteristics of the vegetation of Redwood National Park". MSc Thesis.
- Koch, G. W.; Sillett; Jennings; Davis (April 22, 2004). "The limits to tree height". Nature.
- Ishii, H. T.; Jennings, Gregory M.; Sillett, Stephen C.; Koch, George W. (July 2008). "Hydrostatic constraints on morphological exploitation of light in tall Sequoia sempervirens trees". Oecologia 156 (4): 751. doi:10.1007/s00442-008-1032-z. PMID 18392856.
- Sperry, J. S.; Meinzer; McCulloh (May 2008). "Safety and efficiency conflicts in hydraulic architecture: scaling from tissues to trees. Plant". Plant, Cell, and Enviroment.
- Mullen, L. P.; Sillett, S. C.; Koch, G. W.; Antonie, K. P.; Antoine, M. E. (May 29, 2009). "Physiological consequences of height-related morphological variation in Sequoia sempervirens foliage". Tree Physiology 29 (8): 999. doi:10.1093/treephys/tpp037. PMID 19483187.
- Ishii, H. T.; Azuma, Wakana; Kuroda, Keiko; Sillett, Stephen C. (May 26, 2014). "Pushing the limits to tree height: Could foliar water storage compensate for hydraulic constraints in sequoia sempervirens?". Functional Ecology 28 (5): 1087. doi:10.1111/1365-2435.12284.
- Oldham, A. R.; Sillett, S. C.; Tomescu, A. M. F.; Koch, G. W. (July 2010). "The hydrostatic gradient, not light availability drives height-related variation in Sequoia sempervirens (Cupressaceae) leaf anatomy". American Journal of Botany 97 (7): 1087. doi:10.3732/ajb.0900214. PMID 21616861.
- Dawson, T. E. (1 September 1998). "Fog in the California redwood forest: Ecosystem inputs and used by plants". Oecologia.
- Simonin, K. A.; Santiago, Louis S.; Dawson, Todd E. (July 2009). "Fog interception by Sequoia sempervirens (D. Don) crowns decouples physiology from soil water deficit". Plant, Cell and Enviroment 32 (7): 882. doi:10.1111/j.1365-3040.2009.01967.x.
- Tognetti, R. A.; Longobucco, Anna; Rashi, Antonio; Jones, Mike B. (2001). "Stem hydraulic properties and xylem vulnerability to embolism in three co-occurring Mediterranean shrubs at a natural CO2 spring". Australian Journal of Plant Physiology 28 (4): 257. doi:10.1071/PP00125.
- "Botanical Garden Logistics". UC Berkeley – Biology 1B – Plants & Their Environments (p. 13). Berkeley, California: Department of Integrative Biology, University of California-Berkeley. Archived from the original on 2013-05-13. Retrieved 2014-01-02.
- "IUCN Red List of Threatened Species". Species Survival Commission. Retrieved 2011-08-14.
- "Kia Ora - Welcome to The Redwoods Whakarewarewa Forest". Rotorua District Council. Retrieved November 10, 2011.
- "Redwood History". The New Zealand Redwood Company. Retrieved November 10, 2011.
- "Distribution within Europe". Retrieved 2011-08-14.
- "Longhouse". Retrieved 2011-08-14.
- "RHS Plant Selector Sequoia sempervirens AGM / RHS Gardening". Apps.rhs.org.uk. Retrieved 2012-08-07.
- Tallest Coast Redwoods. Landmark Trees Archive. Retrieved 2010-03-09
- "Tree Climbers International Forum :: Topic: The world's second tallest tree found in Tasmania (1/1)". treeclimbing.com.
- Carder, A (1995). Forest giants of the world: past and present. Ontario: Fitzhenry and Whiteside. ISBN 978-1-55041-090-7.
- Redwood Lumber Industry, Lynwood Carranco. Golden West Books, 1982 - Page 21.
- "Fort Worth Daily Gazette, Fort Worth, Texas. December 9th, 1886 - Page 2". Chroniclingamerica.loc.gov. Retrieved 2012-08-07.
- "Does size matter? John Driscoll/The Times-Standard, Eureka, California. September 8th, 2006". Times-standard.com. Retrieved 2012-08-07.
- Earle, Christopher, ed. (23 Nov 2012). "Pseudotsuga menziesii var. menziesii". The Gymnosperm Database. Retrieved 23 July 2013.
- British Columbia Forest History Newsletter, January 1996
- The New York Times – Topics of The Times, March 7, 1897
- Meehans' Monthly: A Magazine of Horticulture, Botany and Kindred Subjects Published by Thomas Meehan & Sons, 1897 pg. 24
- "The morning times. (Washington, D.C.) 1895-1897, February 28, 1897, PART 2, Page 19, Image 19". loc.gov.
- Ron Judd (Sep. 4, 2011). "Restless Native | Giant logged long ago but not forgotten". The Seattle Times. Retrieved Sep. 7, 2011. Check date values in:
- Van Pelt, R (2001). Forest giants of the Pacific coast. Global Forest Society. pp. 16, 42. ISBN 0-9684143-1-1.
- Koch, G.W., Sillett, S.C., Jennings, G.M., and Davis, S.D. 2004. The limits to tree height. Nature 428: 851–854.
- "Climate explains why West Coast trees are much taller than those in the East". Retrieved 2015-03-10.
- "Cotati residents, scientists scramble to save albino redwood". SFGate.
- "Albino Redwood. Albino Redwoods.". mdvaden.com.
- Stienstra, T (2007-10-11). "It's no snow job: handful of redwoods are rare albinos". San Francisco Chronicle. Retrieved 2011-08-14.
- Van Pelt, R. (2001). Forest Giants of the Pacific Coast. Global Forest. ISBN 0-295-98140-7.
- Largest Coast Redwoods. Landmark Trees Archive. Retrieved 2010-03-09
- Hyperion by M. D. Vaden, Certified Arborist. Hyperion by M. D. Vaden.
-  California State Parks Office of Historic Preservation
- , San Francisco Chronicle, Jim Herron Zamora, Monday, August 14, 2006
- , San Francisco Chronicle, Peter Fimrite, May 8, 2013
- , BayNature, Gordy Slack, July 1, 2004
- Preston, Richard. The Wild Trees: A Story of Passion and Daring, Random House, 2007, ISBN 978-1-4000-6489-2.
- Farjon, A. & Schmid, R. (2011). "Sequoia sempervirens". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 2 January 2014. Database entry includes a lengthy justification of why this species is endangered.
- * Noss, R. F., ed. (2000). The Redwood Forest: history, ecology and conservation of the Coast Redwood. Island Press, Washington, D.C. ISBN 1-55963-726-9.
Sequoia is a genus of redwood coniferous trees in the subfamily Sequoioideae of the family Cupressaceae. The only extant species of the genus is Sequoia sempervirens in the Northern California coastal forests ecoregion of Northern California and Southwestern Oregon in the United States. The two other genera, Sequoiadendron and Metasequoia, in the subfamily Sequoioideae are closely related to Sequoia. It includes the largest trees in the world.
Several extinct species have been named from fossils, including Sequoia affinis, Sequoia chinensis of China, Sequoia langsdorfii, Sequoia dakotensis of South Dakota (Maastrichtian), and Sequoia magnifica.
The name Sequoia was first published as a genus name by the botanist and linguist Stephan Endlicher in 1847. Most modern sources say that the genus was named in honor of Sequoyah, a Cherokee scholar and inventor of the first Cherokee writing system. However, Endlicher left no specific reasons for his choosing that name, and there is no record of anyone stating second-hand that they spoke to him about the origin of the name. As far back as the 1860s it has been debated that perhaps instead the name is an alteration of the Latin word for "sequence", since the species is known to be a follower or remnant of massive ancient, extinct species; the next in a sequence.
In an article published in 2012, author Gary Lowe points out that Endlicher would not have had the fossil knowledge to use as a basis for the idea of a sequence in the name, but rather points to what Endlicher perceived as a sequence of morphological characteristics, and how at that time, the species he was describing, Sequoia sempervirens, seemed to complete a sequence of species in regards to seeds per cone scale.
The most common guess as to the origin of the name, though, is that Endlicher, being also a linguist and author on the mechanics of language himself, gave the name as a Latinized tribute to the developer of the original Cherokee system of writing, Sequoyah.
The genus Sequoia first appears in the fossil record as Sequoia jeholensis, found in Jurassic deposits of South Manchuria. By the late Cretaceous it was already established in Europe, parts of China, and western North America. Comparisons among fossils and modern organisms suggest that by this period Sequoia had already evolved a greater tracheid diameter that allowed it to reach the great heights characteristic of the modern Sequoia sempervirens (coast redwood). Sequoia was not dominant in the tropical high northern latitudes, like Metasequoia, a redwood whose deciduous habit gave it a significant adaptive advantage in an environment with 3 months of continuous darkness. However there still was prolonged range overlap between Sequoia and Metasequoia which could have led to hybridization events that created the modern hexaploid Sequoia sempervirens.
A general cooling trend by the late Eocene and Oligocene reduced the northern ranges of Sequoia. By the end of the Miocene and beginning of the Pliocene, Sequoia fossils were morphologically identical to the modern Sequoia sempervirens. Continued cooling in the Pliocene meant that Sequoia, which is extremely intolerant to frost due to the high water content of its tissues, also became locally extinct in response to the extreme cooling of Europe and Asia In western North America it continued to move south through coastal Oregon and California, surviving due to the abundant rainfall and mild seasons. The Sierra Nevada orogeny further isolated Sequoia because the snowy mountain peaks prevented eastward expansion. The Pleistocene and Holocene distributions are likely nearly identical to the modern S. sempervirens distributions.
- Muir Woods National Monument
- Pacific temperate rain forests (WWF ecoregion)
- Redwood National and State Parks
- Kew World Checklist of Selected Plant Families
- Biota of North America Program 2013 county distribution map
- Endlicher, Stephan (1847). Synopsis Coniferarum. St. Gallen: Scheitlin & Zollikofer.
- Encyclopaedia Britannica, Inc (1 January 2012). Britannica Student Encyclopedia (A-Z Set). Encyclopaedia Britannica, Inc. p. 70. ISBN 978-1-61535-557-0.
- Lowe, Gary D. (2012). "Endlicher's sequence: the naming of the genus Sequoia" (PDF). Fremontia 40 (1 & 2): 25–35. Retrieved January 1, 2014.
- Sierra Nevada - The Naturalist's Companion. University of California Press. 1 June 2000. p. 55. ISBN 978-0-520-92549-6.
- M. R. Ahuja & D. B. Neale (2002). "Origins of polyploidy in coast redwood (Sequoia sempervirens) and relationship of coast redwood to other genera of Taxodiaceae" (PDF). Silvae Genetica 51 (2–3): 93–100.
- Richard Jagels & Maria A. Equiza (2005). "Competitive advantages of Metasequoia in warm high latitudes". In Ben A. LePage, Christopher James Williams & Hong Yang. The Geobiology and Ecology of Metasequoia. Topics in geobiology 22. Dordrecht, the Netherlands: Springer. pp. 335–349. ISBN 1-4020-2631-5.
- Deborah L. Rogers (2000). "Genotypic diversity and clone size in old-growth populations of coast redwood (Sequoia sempervirens)". Canadian Journal of Botany 78 (11): 1408–1419. doi:10.1139/cjb-78-11-1408.
- James Arthur Snyder (1992). The ecology of Sequoia sempervirens: an addendum to "On the edge: nature's last stand for coast redwoods" (M.A. thesis). San Jose State University.
Redwood, including Sequoia sempervirens and Sequoiadendron giganteum , is the state tree of California.
Names and Taxonomy
Steinhauera sempervirens (Voss. S.) Presl.
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