The ecoregion covers 13,300 square kilometres (5,100 sq mi),
extending from just north of the California-Oregon border south, to
southern Monterey County. The ecoregion rarely extends more than 65 km inland from the coast, narrower in the southernmost parts of the ecoregion.
The ecoregion is a sub-ecoregion of the Pacific temperate rain forests ecoregion, which extends up the Pacific Coast to Kodiak Island in Alaska. The ecoregion lies close to the Pacific Ocean,
and is kept moist by Pacific Ocean storms during the winter months, and
by coastal fogs in the summer months. These factors keep the ecoregion
cooler in the summer and warmer in the winter, as compared to ecoregions
further inland. The ecoregion is also defined by the distribution of
the Coast Redwood (Sequoia sempervirens), with isolated groves located in protected canyons as far south as Redwood Gulch, in southern Monterey County. The greatest concentration of remaining Old-growth forest are in the northernmost portion of the ecoregion, primarily within Humboldt and Del Norte counties.
Redwood forests are interspersed with several other plant communities throughout this ecoregion.
Coastal redwood forests
Notholithocarpus densiflorus, with Coast Douglas-firs Pseudotsuga menziesii subsp. menziesii and Coast Redwood behind in Sunset Trail, Big Basin Redwoods State Park, Santa Cruz Mountains, California.
The dominant forest type in this ecoregion is the coastal redwood
forest. These are the tallest forests on Earth, with individual redwood (Sequoia sempervirens)
trees reaching heights of 100 metres (330 ft). These forests are
generally found in areas exposed to coastal fog. In the north, they
occur on upland slopes, in riparian zones, and on riverine terraces. In
the south, where annual precipitation is lower, they are constrained to
coves and ravines. Coast Douglas-firs (Pseudotsuga menziesii var. menziesii) are nearly always associated with redwoods, but in the north the forests can also include Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla) and western red cedar (Thuja plicata). Like coast Douglas-fir, tanoak (Notholithocarpus densiflorus) is often present. Other hardwoods include California bay laurel (Umbellularia californica), red alder (Alnus rubra), madrone (Arbutus menziesii), and bigleaf maple (Acer macrophyllum). The deep shade cast by redwoods often results in a sparse understory, but shade-tolerant species include thimbleberry (Rubus parviflorus), redwood sorrel (Oxalis oregana), elk clover (Aralia californica), dwarf Oregon grape (Mahonia nervosa), salal (Gaultheria shallon), and many ferns, such as deer fern (Blechnum spicant), sword fern (Polystichum munitum), and leathery polypody (Polypodium scouleri).
Trunk in sectional viewRedwood cone scales begin to open mid November, with seeds dispersing by the wind.
Sequoia sempervirens (/səˈkwɔɪ.əˌsɛmpərˈvaɪrənz/) is the sole living species of the genusSequoia 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 1,200–2,200 years or more. This species includes the tallest living trees on Earth, reaching up to 115.9 m (380.1 ft) in height (without the roots) and up to 8.9 m (29 ft) in diameter at breast height. These trees are also among the longest-living trees on Earth. Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated 810,000 ha (2,000,000 acres)
along much of coastal California (excluding southern California where
rainfall is not sufficient) and the southwestern corner of coastal
Oregon within the United States.
The name sequoia sometimes refers to the subfamily Sequoioideae, which includes S. sempervirens along with Sequoiadendron (giant sequoia) and Metasequoia (dawn redwood). Here, the term redwood on its own refers to the species covered in this article but not to the other two species.
Description
The
coast redwood normally reaches a height of 60 to 100 m (200 to 330 ft),
but will be more than 110 m (360 ft) in extraordinary circumstances, with a trunk diameter of 9 m (30 ft). It has a conical crown, with horizontal to slightly drooping branches. The trunk is remarkably straight. The bark can be very thick, up to 35 cm (1.15 ft), 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 (5⁄8–1 in) long and flat on young trees and shaded lower branches in older trees. The leaves are scalelike, 5–10 mm (1⁄4–3⁄8 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 mm (9⁄16–1+1⁄4 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 mm (1⁄8–3⁄16 in) long and 0.5 mm (1⁄32 in) broad, with two wings 1 mm (1⁄16 in) wide. The seeds are released when the cone scales dry and open at maturity. The pollen cones are ovular and 4–6 mm (3⁄16–1⁄4 in) long.
Scottish botanist David Don described the redwood as Taxodium sempervirens, the "evergreen Taxodium", 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. It is unknown how Endlicher derived the name Sequoia. See Sequoia Etymology.
The redwood is one of three living species, each in its own genus, in the subfamily Sequoioideae. Molecular studies have shown that the three are 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.
Names
The species name "sempervirens" means "evergreen", thought to be because of its previous placement in the same genus as Taxodium distichum (baldcypress) of the southeastern USA. Unlike coast redwood, baldcypress loses its leaves in winter. The common name "redwood", applied to both the coast redwood and the giant redwood, is a reference to the red heartwood of the trees. Common names that refer to Sequoia sempervirens alone include "California redwood", "coastal redwood", "coastal sequoia", and "coast redwood".
Distribution and habitat
Coast
redwoods occupy a narrow strip of land approximately 750 km (470 mi) in
length and 8–75 km (5–47 mi) 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 30–750 m (100–2,460 ft) above sea level,
occasionally down to 0 and up to about 900 m (3,000 ft).
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 terrain also made it harder for loggers to get to the trees and to get them out after felling.
The trees above the fog layer, above about 700 m (2,300 ft), 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.
Fog in the 21st century is, however, reduced from what it was in the
prior century, which is a problem that may be compounded by climate change.
Albert Bierstadt, California Redwoods, 1872, Oil on paper mounted on canvas
The ancient range of the genus is considerably greater, with
relatives of the coast redwood living in Europe and Asia prior to the Quaternary
geologic period. In recent geologic time there have been considerable
shifts in the coast redwood's range in North America. Coast redwood bark
has been found in the La Brea Tar Pits, showing that 25,000–40,000 years before the present redwood trees grew as far south as the Los Angeles during the last ice age.
The authors of a 2022 paper suggest, "Were it not for the remarkable
ability to sprout after fire, many southern forests may have lost their Sequoia component long ago."
As to previous redwood range to the north, an upright fossil stump of a
coast redwood on a beach in central Oregon was documented 257 km north
of the current range.
Assisted migration
Coast redwood (2016 photo) planted in Seabeck, WA in 1949.
The ability of Coast Redwood to live for more than a thousand years,
along with its unusual capacity to resprout from its root crown when
felled by natural or human causes, have earned this species the label of
"carbon-sequestration champion." Its potential to contribute toward climate change mitigation, as well as its demonstrated ability to thrive in coastal regions of the Pacific Northwest, led to the formation of a citizen group in Seattle, Washington undertaking assisted migration of this species hundreds of miles north of its native range.
In contrast to cautionary statements made by forestry professionals assessing other tree species for assisted migration,
the citizens involved with the group known as PropagationNation had met
with little controversy until in 2023 a national news outlet published a
lengthy article that cast a favorable light on their efforts. The New York Times Magazine wrote:
Not wanting to cause ecological problems by planting the trees across
the Pacific Northwest, [Philip] Stielstra would eventually contact one
of the foremost experts on the coast redwood, a botanist and forest
ecologist named Stephen Sillett,
at Cal Poly Humboldt, and ask if moving redwoods north was safe.
Sillett thought planting redwoods around Seattle was a fantastic idea.
("It's not like it's going to escape and become a nuisance species,"
Sillett told me, before adding, "it just has so many benefits.") Another
factor encouraged Stielstra too: Millions of years ago, redwoods — or
their close relatives — grew across the Pacific Northwest. By moving
them, Stielstra reasoned, he was helping the magnificent trees regain
lost territory.
In December 2023, the Associated Press exclusively reported criticism from professionals in the region and nationally: While beginning to favor experiments in assisted population migration of more southerly genetics of the main native timber tree, Douglas-fir, professionals were united against large-scale plantings of California redwoods into the Pacific Northwest.
The next month, January 2024, carried a regional news article that,
once again, showed strong support as well as bold statements by the
group's founder.
Even before the controversy developed in Washington state,
professionals in Canada were documenting horticultural plantings of the
California species already in place in southwestern British Columbia.
In 2022 a Canadian Forestry Service publication used northward
horticultural plantings, along with a review of research detailing
redwood's paleobiogeography and current range conditions, as grounds for proposing that Canada's Vancouver Island already offered "narrow strips of optimal habitat" for extending the range of coast redwood.
The authors point to a topographical "bottleneck" north of the
California border that could have impeded northward migration during the
Holocene. The bottleneck entails a lack of lowland passages through the
Oregon Coast Range north of the Chetco River, coupled with the absence of coastal landscapes beyond storm salt-spray and tsunami inundation — for which this conifer species is highly intolerant.
Ecology
Fog and flood adaptations
Fog is of major importance in coast redwood ecology. Redwood National Park.Cross section of a Sequoia sempervirens showing tree rings
The native area provides a unique environment with heavy seasonal rains up to 2,500 mm (100 in) annually. Cool coastal air and fog drip
keep the 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, and making efficient recycling of dead trees
especially important. 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, birds, mammals, and reptiles. Old-growth redwood stands provide habitat for the federally threatened spotted owl and the California-endangered marbled murrelet.
The height of S. sempervirens is closely tied to fog availability; 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 difficult due to gravity.
Despite the high rainfall that the region receives (up to 100 cm), the
leaves in the upper canopy are perpetually stressed for water. This water stress is exacerbated by long droughts in the summer.
Water stress is believed to cause the morphological changes in the
leaves, stimulating reduced leaf length and increased leaf succulence.
To supplement their water needs, redwoods use frequent summer fog
events. Fog water is absorbed through multiple pathways. Leaves directly
take in fog from the surrounding air through the epidermal tissue, bypassing the xylem. Coast redwoods also absorb water directly through their bark. The uptake of water through leaves and bark repairs and reduces the severity of xylem embolisms, which occur when cavitations form in the xylem preventing the transport of water and nutrients.
Fog may also collect on redwood leaves, drip to the forest floor, and
be absorbed by the tree's roots. This fog drip may form 30% of the total
water used by a tree in a year.
Redwoods often grow in flood-prone areas. Sediment deposits can
form impermeable barriers that suffocate tree roots, and unstable soil
in flooded areas often causes trees to lean to one side, increasing the
risk of the wind toppling them. Immediately after a flood, redwoods grow
their existing roots upwards into recently deposited sediment layers. A second root system then develops from adventitious buds on the newly buried trunk and the old root system dies. To counter lean, redwoods increase wood production on the vulnerable side, creating a supporting buttress. These adaptations create forests of almost exclusively redwood trees in flood-prone regions.
Pest and pathogen resistance
A recently fallen canopy branch reveals thin bark and tunnels made by bark beetle larvae.
Coast redwoods are resistant to insect attack, fungal infection, and rot. These properties are conferred by concentrations of terpenoids and tannic acid in redwood leaves, roots, bark, and wood.
Despite these chemical defenses, redwoods are still subject to insect
infestations; none, however, are capable of killing a healthy tree. Bark
is so thick on the bole that bark beetles cannot enter there. However,
the canopy branches have thin bark (see photo at right) that native bark
beetles are able to bore into for egg-laying and larval growth via
tunnels.
Redwoods also face herbivory from mammals: black bears are reported to consume the inner bark of small redwoods, and black-tailed deer are known to eat redwood sprouts.
The oldest known coast redwood is about 2,200 years old; many others in the wild exceed 600 years. The numerous claims of older redwoods 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". Redwoods must endure various environmental disturbances to attain such great ages.
Fire adaptations
In
response to forest fires, the trees have developed various adaptations.
The thick, fibrous bark of coast redwoods is extremely fire-resistant;
it grows to at least a foot thick and protects mature trees from fire
damage. In addition, the redwoods contain little flammable pitch or resin. Fires, moreover, appear to actually benefit redwoods by causing substantial mortality in competing species, while having only minor effects on redwood. Burned areas are favorable to the successful germination of redwood seeds.
A study published in 2010, the first to compare post-wildfire survival
and regeneration of redwood and associated species, concluded that fires
of all severity increase the relative abundance of redwood, and
higher-severity fires provide the greatest benefit.
Two years after the 2020 CZU fire that burned as high as the canopy in Big Basin Redwoods State Park.
In addition to the customary sprouting of massive numbers of vertical
shoots growing at ground-level around the charred trunks, thick epicormic
greenery appears high up on some of the fire-pruned redwoods. (Photos
were taken along the old growth loop trail, September 2022.)
Self-pruning of its lower limbs as height is gained is a crucial
adaptation to prevent ground fires from rising into the canopy, where
branch bark is thin and leaves are vulnerable. In the millions of years
that predated human evolution, this level of protection worked well
against natural fires originating from lightning strikes.
When the first humans arrived in North America, redwoods thrived in regions where ground fires were intentionally set by indigenous populations on a seasonal basis. However, when peoples arrived from other continents in the past few centuries, indigenous fire practices
were disallowed — even in the few places where the first peoples were
permitted to continue living. Flammable brush and young trees thus
accumulated.
Clearcut logging further hampered a return to a fire-resistant tall canopy. Governmental policies aimed at suppressing
all natural and human-caused fires, even in parks and wilderness areas,
amplified the accumulation of dense undergrowth and woody debris. Thus,
even a naturally occurring ground fire could threaten to spread upwards
and become a canopy fire spreading uncontrollably over a widening area.
Reproduction
Lignotuber actively budding.Lignotuber, Roosevelt Grove.Basal regrowth after logging.View upward from the center of an old, logged stump (Freshwater Creek).
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. Cones develop in the
winter and mature by fall. In the early stages, the cones look like flowers,
and are commonly called "flowers" by professional foresters, although
this is not strictly correct. Coast redwoods produce many cones, with
redwoods in new forests producing thousands per year.
The cones themselves hold 90–150 seeds, but viability of seed is low,
typically well below 15% with one estimate of average rates being 3 to
10 percent.The viability does increase with age, trees under 20 years old have a
viability of about 1%, and do not generally reach the highest levels of
viability until age 250. The rates decrease as the tree starts to get
very old, with trees over 1,200 not reaching viability rates over 3%. The low viability may discourage seed predators, which do not want to waste time sorting chaff
(empty seeds) from edible seeds. Successful germination often requires a
fire or flood, reducing competition for seedlings. 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 (200–390 ft)
from the parent tree. Seedlings are susceptible to fungal infection and
predation by banana slugs, brush rabbits, and nematodes. Most seedlings do not survive their first three years.
However, those that become established grow rapidly, with young trees
known to reach 20 m (66 ft) tall in 20 years. When canopy space is not
available, small trees can remain suppressed for up to 400 years before
accelerating their growth rate.
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 generates 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 develops 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
(7 ft 7 in) 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 m (10 ft) in depth from the soil surface. Coast
redwoods develop burls as seedlings from the axils of their cotyledon, a trait that is extremely rare in conifers.
When provoked by damage, dormant buds in the burls sprout new shoots
and roots. Burls are also 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.
Cultivation and uses
An example of a bonsai redwood, from the Pacific Bonsai Museum
Coast redwood is one of the most valuable timber species in the lumbering industry. In California, 3,640 km2 (899,000 acres) 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 has had a more storied role than the Pacific Lumber Company (1863–2008) of Humboldt County, California, where it owned and managed over 810 km2
(200,000 acres) 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 absorb water and resist 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 Yurok people, who occupied the region before European settlement, regularly burned ground cover in redwood forests to bolster tanoak
populations from which they harvested acorns, to maintain forest
openings, and to boost populations of useful plant species such as those
for medicine or basketmaking.
Extensive logging of redwoods began in the early nineteenth
century. The trees were felled by ax and saw onto beds of tree limbs and
shrubs to cushion their fall. Stripped of their bark, the logs were transported to mills or waterways by oxen or horse. Loggers then burned the accumulated tree limbs, shrubs, and bark. The repeated fires favored secondary forests of primarily redwoods as redwood seedlings sprout readily in burned areas. The introduction of steam engines let crews drag logs through long skid trails to nearby railroads, furthering the reach of loggers beyond the land near rivers previously used to transport trees.
This method of harvesting, however, disturbed large amounts of soil,
producing secondary-growth forests of species other than redwood such as
Douglas-fir, grand fir, and western hemlock. After World War II, trucks and tractors gradually replaced steam engines, giving rise to two harvesting approaches: clearcutting
and selection harvesting. Clearcutting involved felling all the trees
in a particular area. It was encouraged by tax laws that exempted all
standing timber from taxation if 70% of trees in the area were
harvested.[52]
Selection logging, by contrast, called for the removal 25% to 50% of
mature trees in the hopes that the remaining trees would allow for
future growth and reseeding.
This method, however, encouraged growth of other tree species,
converting redwood forests into mixed forests of redwood, grand fir, Sitka spruce, and western hemlock.Moreover, the trees left standing were often felled by windthrow; that is, they were often blown over by the wind.
The coast redwood is naturalized in New Zealand, notably at Whakarewarewa Forest, Rotorua.
Redwood has been grown in New Zealand plantations for more than 100
years, and those planted in New Zealand have higher growth rates than
those in California, mainly because of even rainfall distribution
through the year.
Other areas of successful cultivation outside of the native range include Great Britain, Italy, France, Haida Gwaii, middle elevations of Hawaii, Hogsback
in South Africa, the Knysna Afromontane forests in the Western Cape,
Grootvadersbosch Forest Reserve near Swellendam, South Africa and the
Tokai Arboretum on the slopes of Table Mountain above Cape Town, 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.
Fairly solid evidence indicates that coast redwoods were the world's
largest trees before logging, with numerous historical specimens
reportedly over 122 m (400 ft).
The theoretical maximum potential height of coast redwoods is thought
to be limited to between 122 and 130 m (400 and 427 ft), as evapotranspiration is insufficient to transport water to leaves beyond this range. Further studies have indicated that this maximum requires fog, which is prevalent in these trees' natural environment.
A tree reportedly 114.3 m (375 ft) in length was felled in Sonoma County by the Murphy Brothers saw mill in the 1870s, another claimed to be 115.8 m (380 ft) and 7.9 m (26 ft) in diameter was cut down near Eureka in 1914, and the Lindsey Creek tree
was documented to have a height of 120 m (390 ft) when it was uprooted
and felled by a storm in 1905. A tree reportedly 129.2 m (424 ft) tall
was felled in November 1886 by the Elk River Mill and Lumber Company in
Humboldt County, yielding 79,736 marketable board feet from 21 cuts. In 1893, a Redwood cut at the Eel River, near Scotia, reportedly measured 130.1 m (427 ft) in length, and 23.5 m (77 ft) in girth. However, limited evidence corroborates these historical measurements.
Today, trees over 60 m (200 ft) are common, and many are over 90 m (300 ft). The current tallest tree is the Hyperion tree, measuring 115.61 m (379.3 ft). The tree was discovered in Redwood National Park during mid-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 112.84 m (370.2 ft) (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 113.4 m
(372 ft) high and estimated to be 1,600 years old. This fallen giant has
been preserved in the park.
The largest known living coast redwood is Grogan's Fault,
discovered in 2014 by Chris Atkins and Mario Vaden in Redwood National
Park, with a main trunk volume of at least 1,084.5 cubic meters (38,299 cu ft) Other high-volume coast redwoods include Iluvatar, with a main trunk volume of 1,033 m3 (36,470 cu ft),[71]: 160 and the Lost Monarch, with a main trunk volume of 988.7 m3 (34,914 cu ft).
Albino redwoods are mutants that cannot manufacture chlorophyll. About 230 examples (including growths and sprouts) are known to exist, reaching heights of up to 20 m (66 ft). These trees survive like parasites,
obtaining food from green parent trees. While similar mutations occur
sporadically in other conifers, no cases are known of such individuals
surviving to maturity in any other conifer species.
Recent research news reports that albino redwoods can store higher
concentrations of toxic metals, going so far as comparing them to organs
or "waste dumps".
Heights of the tallest coast redwoods are measured yearly by experts. Even with recent discoveries of tall coast redwoods above 100 m (330 ft), it is likely that no taller trees will be discovered.
Diameter is measured at 1.4 m (4 ft 7 in) above average ground level (at breast height).
Details of the precise locations for most of the tallest trees were not
announced to the general public for fear of causing damage to the trees
and the surrounding habitat.
The tallest coast redwood easily accessible to the public is the
National Geographic Tree, immediately trailside in the Tall Trees Grove
of Redwood National Park.
List of largest trees
The following list shows the largest S. sempervirens by volume known as of 2001.
Calculating the volume of a standing tree is the practical equivalent of calculating the volume of an irregular cone,
and is subject to error for various reasons. This is partly due to
technical difficulties in measurement, and variations in the shape of
trees and their trunks. Measurements of trunk circumference are taken at only a few predetermined heights up the trunk, and assume that the trunk is circular in cross-section,
and that taper between measurement points is even. Also, only the
volume of the trunk (including the restored volume of basal fire scars)
is taken into account, and not the volume of wood in the branches or
roots. The volume measurements also do not take cavities into account. Most coast redwoods with volumes greater than 850 m3
(30,000 cu ft) represent ancient fusions of two or more separate trees,
which makes determining whether a coast redwood has a single stem or
multiple stems difficult.
Starting in 2014, more record-breaking coast redwood trees were
discovered. The largest disclosed was a massive redwood called Grogan's
Fault/Spartan,
which has been measured to have a volume of 38,300 cubic feet. In 2021
during a meeting presentation titled Redwoods 101 run by Henry Cowell
Redwoods State Park, an even larger redwood was revealed, allegedly
surpassed only by 3 giant sequoias in size. This tree is popularly known as 'Hail Storm', and has a volume of 44,750 cubic feet.
Details of the precise locations for most of the tallest trees
were not announced to the general public for fear of causing damage to
the trees and the surrounding habitat. The largest coast redwood easily accessible to the public is Iluvatar, which stands prominently about 5 meters (16 ft) to the southeast of the Foothill Trail of Prairie Creek Redwoods State Park.
Redwood canopy soil forms from leaf and organic material litter
shedding from upper portions of the tree, accumulating and decomposing
on larger branches.
These clusters of soil require a lot of hydration, but they have an
incredible amount of retention once saturated. Redwoods can send roots
into these wet soils, providing a water source removed from the forest
floor. This creates a unique ecosystem within old growth trees full of
fungi, vascular plants, and small creatures. An example of a creature
that lives there are the Clouded Salamanders that has been discovered up
to 40 meters high. Evidence shows they breed and are born in the canopy
soil of Redwood trees.
Due to the sheer mass height of these trees and the canopy layer, it
was almost never explored for the last century. Due to the mass of these
trees and the amount of trees in the surrounding area different molds
of moss form on these canopies that are called epiphytes. These
epiphytes have different characteristics but all of said species are
very adaptable to the tough treetop weather and characteristics.
After hundreds of years these trees have been shaped into making it
possible for these epiphytes to survive through the winter rain and the
fall fog.
The Crannell Creek Giant was documented to have a trunk volume of at least 1,744 m3 (61,573 cu ft) – about 32% larger than Grogan's Fault and 17% larger than General Sherman, the current largest tree. It was felled around 1945.
The Lindsey Creek tree
was documented to have a height of 120 m (390 ft) and a trunk volume of
at least 2,500 cubic meters (90,000 cu ft) when it was uprooted and
felled by a storm in 1905. If these measurements are to be believed, the
Lindsey Creek tree was about 3 m (10 ft) taller than Hyperion, the
current tallest tree, 213% larger than Grogan's Fault, and 171% larger
than General Sherman.
Old Survivor, also known as the Grandfather, is the last remaining old-growth coastal redwood of the redwood forest that populated the Oakland Hills. The tree was seeded sometime between 1549 and 1554.
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