In botany , the trunk (or bole ) is the stem and main wooden axis of a tree , which is an important feature in tree identification, and which often differs markedly from the bottom of the trunk to the top, depending on the species.
111-492: Sequoiadendron giganteum , also known as the giant sequoia , giant redwood , Sierra redwood or Wellingtonia is a coniferous tree , classified in the family Cupressaceae in the subfamily Sequoioideae . Giant sequoia specimens are the most massive trees on Earth. They are native to the groves on the western slopes of the Sierra Nevada mountain range of California but have been introduced, planted, and grown around
222-604: A fossil record extending back about 300 million years to the Paleozoic in the late Carboniferous period; even many of the modern genera are recognizable from fossils 60–120 million years old. Other classes and orders, now long extinct, also occur as fossils, particularly from the late Paleozoic and Mesozoic eras. Fossil conifers included many diverse forms, the most dramatically distinct from modern conifers being some herbaceous conifers with no woody stems. Major fossil orders of conifers or conifer-like plants include
333-526: A paleoendemic species, they occur in scattered groves, with a total of 81 groves (see list of sequoia groves for a full inventory), comprising a total area of only 144.16 km (35,620 acres). Nowhere does it grow in pure stands, although in a few small areas, stands do approach a pure condition. The northern two-thirds of its range, from the American River in Placer County southward to
444-697: A sister group to Pinales (the 'gnepine' hypothesis) or as being more derived than Pinales but sister to the rest of the group. Most recent studies favor the 'gnepine' hypothesis. The earliest conifers appear in the fossil record during the Late Carboniferous ( Pennsylvanian ), over 300 million years ago. Conifers are thought to be most closely related to the Cordaitales , a group of extinct Carboniferous-Permian trees and clambering plants whose reproductive structures had some similarities to those of conifers. The most primitive conifers belong to
555-426: A 1-millimeter (0.04 in) wide, yellow-brown wing along each side. Some seeds shed when the cone scales shrink during hot weather in late summer, but most are liberated by insect damage or when the cone dries from the heat of fire. The trees do not begin to bear cones until they are 12 years old. Trees may produce sprouts from their stumps subsequent to injury, until about 20 years old; however, shoots do not form on
666-587: A 1859 feature in Hutchings' Illustrated California Magazine , which promoted tourism to the grove. Before Augustus T. Dowd's well-known discovery in 1852, there were three earlier encounters with giant sequoias. The first known mention of the giant sequoia by a European American was in 1833 by explorer J.K. Leonard, who recorded it in his diary. While Leonard did not specify a location, his travels likely took him through Calaveras Grove , but this observation remained unnoticed. In 1850, John M. Wooster encountered
777-422: A female multicellular gametophyte. The female gametophytes grow to produce two or more archegonia , each of which contains an egg. Upon fertilization, the diploid egg will give rise to the embryo, and a seed is produced. The female cone then opens, releasing the seeds which grow to a young seedling . Conifer reproduction is synchronous with seasonal changes in temperate zones. Reproductive development slows to
888-399: A female cone and are drawn into a tiny opening on the ovule called the micropyle . It is within the ovule that pollen-germination occurs. From here, a pollen tube seeks out the female gametophyte, which contains archegonia each with an egg, and if successful, fertilization occurs. The resulting zygote develops into an embryo , which along with the female gametophyte (nutritional material for
999-438: A few are shrubs . Examples include cedars , Douglas-firs , cypresses , firs , junipers , kauri , larches , pines , hemlocks , redwoods , spruces , and yews . As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species. Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over large areas of land, most notably
1110-749: A fire. Giant sequoias are a pioneer species , and are having difficulty reproducing in their original habitat (and very rarely reproduce in cultivation) due to the seeds only being able to grow successfully in full sun and in mineral-rich soils, free from competing vegetation. Although the seeds can germinate in moist needle humus in the spring, these seedlings will die as the duff dries in the summer. They therefore require periodic wildfire to clear competing vegetation and soil humus before successful regeneration can occur. Without fire, shade-loving species will crowd out young sequoia seedlings, and sequoia seeds will not germinate. These trees require large amounts of water and are often concentrated near streams. Their growth
1221-657: A giant sequoia at Calaveras Grove and carved his initials into the bark of the "Hercules" tree. A year later, in 1851, Robert Eccleston traveled through Nelder Grove with a small detachment of the Mariposa Battalion during the Mariposa War . Similar to Leonard's experience, these encounters also received no publicity. The first scientific naming of the species was by John Lindley in December 1853, who named it Wellingtonia gigantea , without realizing this
SECTION 10
#17327660042811332-746: A group of giant sequoias was planted by the United States Forest Service in the San Jacinto Mountains of Southern California in the immediate aftermath of a wildfire that left the landscape barren. The giant sequoias were rediscovered in 2008 by botanist Rudolf Schmid and his daughter Mena Schmidt while hiking on Black Mountain Trail through Hall Canyon. Black Mountain Grove is home to over 150 giant sequoias, some of which stand over 6.1 m (20 ft) tall. This grove
1443-665: A halt during each winter season and then resumes each spring. The male strobilus development is completed in a single year. Conifers are classified by three reproductive cycles that refer to the completion of female strobilus development from initiation to seed maturation. All three types of reproductive cycle have a long gap between pollination and fertilization . One year reproductive cycle : The genera include Abies , Picea , Cedrus , Pseudotsuga , Tsuga , Keteleeria ( Pinaceae ) and Cupressus , Thuja , Cryptomeria , Cunninghamia and Sequoia ( Cupressaceae ) . Female strobili are initiated in late summer or fall of
1554-413: A maximum of energy from weak sunshine at high latitudes or under forest canopy shade. Conifers from hotter areas with high sunlight levels (e.g. Turkish pine Pinus brutia ) often have yellower-green leaves, while others (e.g. blue spruce , Picea pungens ) may develop blue or silvery leaves to reflect ultraviolet light. In the great majority of genera the leaves are evergreen , usually remaining on
1665-880: A needle-like appearance, but others, including most of the Cupressaceae and some of the Podocarpaceae , have flat, triangular scale-like leaves. Some, notably Agathis in Araucariaceae and Nageia in Podocarpaceae, have broad, flat strap-shaped leaves. Others such as Araucaria columnaris have leaves that are awl-shaped. In the majority of conifers, the leaves are arranged spirally, the exceptions being most of Cupressaceae and one genus in Podocarpaceae, where they are arranged in decussate opposite pairs or whorls of 3 (−4). In many species with spirally arranged leaves, such as Abies grandis (pictured),
1776-402: A protective cone called a strobilus . The cones take from four months to three years to reach maturity, and vary in size from 2 to 600 millimetres ( 1 ⁄ 8 to 23 + 5 ⁄ 8 in) long. In Pinaceae , Araucariaceae , Sciadopityaceae and most Cupressaceae , the cones are woody , and when mature the scales usually spread open allowing the seeds to fall out and be dispersed by
1887-487: A serious environmental issue causing problems for pastoral farming and for conservation . Radiata pine was introduced to Australia in the 1870s. It is "the dominant tree species in the Australian plantation estate" – so much so that many Australians are concerned by the resulting loss of native wildlife habitat. The species is widely regarded as an environmental weed across southeastern and southwestern Australia and
1998-406: A single white spruce tree from 1926 to 1961. Apical growth of the stem was slow from 1926 through 1936 when the tree was competing with herbs and shrubs and probably shaded by larger trees. Lateral branches began to show reduced growth and some were no longer in evidence on the 36-year-old tree. Apical growth totaling about 340 m, 370 m, 420 m, 450 m, 500 m, 600 m, and 600 m was made by the tree in
2109-526: A specific length, called bolts . The term "log" is informally used in English to describe any felled trunk not rooted in the ground, whose roots are detached. A stump is the part of a trunk remaining in the ground after the tree has been felled, or the earth-end of an uprooted tree which retains its un-earthed roots. The trunk consists of five main parts: The outer bark , inner bark ( phloem ), cambium, sapwood (live xylem ), and heartwood (dead xylem). From
2220-469: A useful guide by which to assess the adequacy of particular nutrients, and the ratios among the major nutrients are helpful guides to nutritional imbalances. The softwood derived from conifers is of great economic value, providing about 45% of the world's annual lumber production. Other uses of the timber include the production of paper and plastic from chemically treated wood pulp. Some conifers also provide foods such as pine nuts and juniper berries ,
2331-614: A volume of 1,489 m (52,600 cu ft); by way of comparison, the largest giant sequoias in Great Britain have volumes no greater than 90–100 m (3,200–3,500 cu ft), one example being the 90 m (3,200 cu ft) specimen in the New Forest . Sequoiadendron giganteum has gained the Royal Horticultural Society 's Award of Garden Merit . An avenue of 218 giant sequoias
SECTION 20
#17327660042812442-591: A year, then they overwinter. Female strobili emerge followed by pollination in the following spring. Fertilization takes place in summer of the following year, only 3–4 months after pollination. Cones mature and seeds are then shed by the end of that same year. Pollination and fertilization occur in a single growing season. Two-year reproductive cycle : The genera includes Widdringtonia , Sequoiadendron ( Cupressaceae ) and most species of Pinus . Female strobilus initials are formed in late summer or fall then overwinter. Female strobili emerge and receive pollen in
2553-524: Is 3,200–3,266 years old based on dendrochronology . That tree has been verified to have the fourth-largest lifespan of any tree, after individuals of Great Basin bristlecone pine and alerce . Giant sequoia bark is fibrous, furrowed, and may be 90 cm (3 ft) thick at the base of the columnar trunk. The sap contains tannic acid , which provides significant protection from fire damage. The leaves are evergreen , awl-shaped, 3–6 mm ( 1 ⁄ 8 – 1 ⁄ 4 in) long, and arranged spirally on
2664-446: Is a coast redwood ( Sequoia sempervirens ), with a height of 115.55 metres (although one mountain ash, Eucalyptus regnans , allegedly grew to a height of 140 metres, the tallest living angiosperms are significantly smaller at around 100 metres. ) The thickest (that is, the tree with the greatest trunk diameter ) is a Montezuma cypress ( Taxodium mucronatum ), 11.42 metres in diameter. The largest tree by three-dimensional volume
2775-418: Is a giant sequoia ( Sequoiadendron giganteum ), with a volume 1486.9 cubic metres. The smallest is the pygmy pine ( Lepidothamnus laxifolius ) of New Zealand, which is seldom taller than 30 cm when mature. The oldest non-clonal living tree is a Great Basin bristlecone pine ( Pinus longaeva ), 4,700 years old. Since most conifers are evergreens, the leaves of many conifers are long, thin and have
2886-531: Is a very popular ornamental tree in many parts of the world. The etymology of the genus name was long presumed—initially in The Yosemite Book by Josiah Whitney in 1868—to be in honor of Sequoyah (1767–1843), who was the inventor of the Cherokee syllabary . An etymological study published in 2012 debunked that "American myth," concluding that Austrian Stephen L. Endlicher derived the name from
2997-407: Is dependent on soil moisture. Squirrels, chipmunks, finches and sparrows consume the freshly sprouted seedlings, preventing their growth. Fires also bring hot air high into the canopy via convection , which in turn dries and opens the cones. The subsequent release of large quantities of seeds coincides with the optimal postfire seedbed conditions. Loose ground ash may also act as a cover to protect
3108-681: Is estimated to have wiped out 10-14% of the giant sequoia population, or about 7,500 to 10,600 mature trees, possibly including the King Arthur Tree , one of the tallest known sequoias. In 2021, the KNP Complex and Windy Fire added to the damage, killing an estimated 3 to 5% more of the population. Controlled burns have been effective in protecting giant sequoias. In the 2022 Washburn Fire , officials credited prescribed burns in Yosemite National Park with limiting
3219-420: Is he not the greatest light in the woods, in the world? Where are such columns of sunshine, tangible, accessible, terrestrialized?' Wood from mature giant sequoias is highly resistant to decay, but due to being fibrous and brittle, it is generally unsuitable for construction. From the 1880s through the 1920s, logging took place in many groves in spite of marginal commercial returns. The Hume-Bennett Lumber Company
3330-656: Is limited to a small area of California, it was once much more widely distributed in prehistoric times, and was a reasonably common species in North American and Eurasian coniferous forests until its range was greatly reduced by the last ice age . Older fossil specimens reliably identified as giant sequoia have been found in Cretaceous era sediments from a number of sites in North America and Europe, and even as far afield as New Zealand and Australia. In 1974,
3441-549: Is not to be confused with the Black Mountain Grove in the southern Sierra. Nearby Lake Fulmor Grove is home to seven giant sequoias, the largest of which is 20 m (66 ft) tall. The two groves are located approximately 175 mi (282 km) southeast of the southernmost naturally occurring giant sequoia grove, Deer Creek Grove . It was later discovered that the United States Forest Service had planted giant sequoias across Southern California. However,
Sequoiadendron giganteum - Misplaced Pages Continue
3552-402: Is probably: first to apical growth and new needle formation, then to buds for the next year's growth, with the cambium in the older parts of the branches receiving sustenance last. In the white spruce studied by Fraser et al. (1964), the needles constituted 17.5% of the over-day weight. Undoubtedly, the proportions change with time. Wind and animal dispersals are two major mechanisms involved in
3663-432: Is the whitespotted sawyer ( Monochamus scutellatus ). Adults are found in summer on newly fallen or recently felled trees chewing tiny slits in the bark in which they lay eggs. The eggs hatch in about two weeks and the tiny larvae tunnel to the wood and score its surface with their feeding channels. With the onset of cooler weather, they bore into the wood, making oval entrance holes and tunnelling deeply. Feeding continues
3774-428: Is usually found in a humid climate characterized by dry summers and snowy winters. Most giant sequoia groves are on granitic-based residual and alluvial soils. The elevation of the giant sequoia groves generally ranges from 1,400–2,000 m (4,600–6,600 ft) in the north, to 1,700–2,150 metres (5,580–7,050 ft) to the south. Giant sequoias generally occur on the south-facing sides of northern mountains, and on
3885-639: The Calaveras Grove by William Lobb , acting for the Veitch Nursery near Exeter , arrived in England in December 1853; seed from this batch was widely distributed throughout Europe. Growth in Britain is very fast, with the tallest tree, at Benmore in southwest Scotland, reaching 56.4 m (185 ft) in 2014 at age 150 years, and several others from 50–53 m (164–174 ft) tall;
3996-623: The Cephalotaxaceae may be better included within the Taxaceae, and some authors additionally recognize Phyllocladaceae as distinct from Podocarpaceae (in which it is included here). The family Taxodiaceae is here included in the family Cupressaceae, but was widely recognized in the past and can still be found in many field guides. A new classification and linear sequence based on molecular data can be found in an article by Christenhusz et al. The conifers are an ancient group, with
4107-583: The Cordaitales , Vojnovskyales , Voltziales and perhaps also the Czekanowskiales (possibly more closely related to the Ginkgophyta ). Pinaceae Araucariaceae Podocarpaceae Sciadopityaceae Cupressaceae Cephalotaxaceae Taxaceae Multiple studies also indicate that the Gnetophyta belong within the conifers despite their distinct appearances, either placing them as
4218-663: The Kings River , has only eight disjunct groves. The remaining southern groves are concentrated between the Kings River and the Deer Creek Grove in southern Tulare County . Groves range in size from 12.4 km (3,100 acres) with 20,000 mature trees, to small groves with only six living trees. Many are protected in Sequoia and Kings Canyon National Parks and Giant Sequoia National Monument . The giant sequoia
4329-743: The Mesozoic era. Modern groups of conifers emerged from the Voltziales during the Late Permian through Jurassic . Conifers underwent a major decline in the Late Cretaceous corresponding to the explosive adaptive radiation of flowering plants . All living conifers are woody plants, and most are trees, the majority having a monopodial growth form (a single, straight trunk with side branches) with strong apical dominance . Many conifers have distinctly scented resin , secreted to protect
4440-673: The National Institute of Food and Agriculture as part of a species conservation, restoration and management effort. The giant sequoia first gained widespread attention in 1852 when grizzly hunter Augustus T. Dowd discovered the Discovery Tree in Calaveras Grove , marking the species' first widely publicized discovery by non-natives. The tree was cut down in 1853 and exhibited across the United States. The story of Dowd's discovery gained further notoriety following
4551-460: The influence of environmental conditions, their anatomical characteristics record growth rate changes produced by these changing conditions. The microscopic structure of conifer wood consists of two types of cells : parenchyma , which have an oval or polyhedral shape with approximately identical dimensions in three directions, and strongly elongated tracheids. Tracheids make up more than 90% of timber volume. The tracheids of earlywood formed at
Sequoiadendron giganteum - Misplaced Pages Continue
4662-484: The taiga of the Northern Hemisphere , but also in similar cool climates in mountains further south. Boreal conifers have many wintertime adaptations. The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally alter their biochemistry to make them more resistant to freezing. While tropical rainforests have more biodiversity and turnover,
4773-402: The wind . In some (e.g. firs and cedars ), the cones disintegrate to release the seeds, and in others (e.g. the pines that produce pine nuts ) the nut-like seeds are dispersed by birds (mainly nutcrackers , and jays ), which break up the specially adapted softer cones. Ripe cones may remain on the plant for a varied amount of time before falling to the ground; in some fire-adapted pines,
4884-409: The 16 nutrient elements known to be essential to plants, 13 of which are obtained from the soil, including nitrogen , phosphorus , potassium , calcium , magnesium , and sulfur , all used in relatively large amounts. Nutrient concentrations in conifers also vary with season, age, and kind of tissue sampled, and analytical technique. The ranges of concentrations occurring in well-grown plants provide
4995-643: The Latin word sequi (meaning to follow ), because the number of seeds per cone in the newly classified genus aligned in mathematical sequence with the other four genera in the suborder. Giant sequoia specimens are the most massive individual trees in the world. They grow to an average height of 50–85 m (164–279 ft) with trunk diameters ranging from 6–8 m (20–26 ft). Record trees have been measured at 94.8 m (311 ft) tall. Trunk diameters of 17 m (56 ft) have been claimed via research figures taken out of context. The specimen known to have
5106-743: The North American Forest Tree Nursery Soils Workshop at Syracuse in 1980 provided strong contrary evidence: Bob Eastman, President of the Western Maine Forest Nursery Co. stated that for 15 years he has been successful in avoiding winter “burn” to Norway spruce and white spruce in his nursery operation by fertilizing with 50–80 lb/ac (56–90 kg/ha) nitrogen in September, whereas previously winter burn had been experienced annually, often severely. Eastman also stated that
5217-464: The Pinales without Taxales as paraphyletic , and the latter order is no longer considered distinct. A more accurate subdivision would be to split the class into three orders, Pinales containing only Pinaceae, Araucariales containing Araucariaceae and Podocarpaceae, and Cupressales containing the remaining families (including Taxaceae), but there has not been any significant support for such a split, with
5328-583: The US. Conifer Conifers are a group of cone-bearing seed plants , a subset of gymnosperms . Scientifically, they make up the division Pinophyta ( / p ɪ ˈ n ɒ f ɪ t ə , ˈ p aɪ n oʊ f aɪ t ə / ), also known as Coniferophyta ( / ˌ k ɒ n ɪ f ə ˈ r ɒ f ɪ t ə , - oʊ f aɪ t ə / ) or Coniferae . The division contains a single extant class , Pinopsida . All extant conifers are perennial woody plants with secondary growth . The great majority are trees , though
5439-536: The United States is a specimen planted near Ribeauvillé in France in 1856 and measured in 2014 at a height between 57.7 m (189 ft) and 58.1 m (191 ft) at age 158 years. The giant sequoia was first brought into cultivation in Britain in 1853 by the horticulturist Patrick Matthew of Perthshire from seeds sent by his botanist son John in California. A much larger shipment of seed collected from
5550-558: The beginning of a growing season have large radial sizes and smaller, thinner cell walls . Then, the first tracheids of the transition zone are formed, where the radial size of cells and the thickness of their cell walls changes considerably. Finally, latewood tracheids are formed, with small radial sizes and greater cell wall thickness. This is the basic pattern of the internal cell structure of conifer tree rings. Most conifers are monoecious , but some are subdioecious or dioecious ; all are wind-pollinated . Conifer seeds develop inside
5661-604: The buildup of fuel and the excessive growth of more fire-sensitive trees, like white fir , have increased the risk of devastating crown fires , which have already destroyed significant portions of the sequoia population. Many destructive wildfires have hit giant sequoia groves in recent decades, including the McNally Fire in 2002, the Rough Fire in 2015, and the Railroad Fire in 2017. The Castle Fire in 2020
SECTION 50
#17327660042815772-508: The coast redwood. The name Washingtonia californica was also applied to it by Winslow in 1854; this name too is invalid, since it was already used for the palm genus Washingtonia . In 1907, it was placed by Carl Ernst Otto Kuntze in the otherwise fossil genus Steinhauera , but doubt as to whether the giant sequoia is related to the fossil originally so named makes this name invalid. These nomenclatural oversights were corrected in 1939 by John Theodore Buchholz , who also pointed out
5883-587: The cone consists of several fused scales, while in others (e.g. Taxaceae), the cone is reduced to just one seed scale or (e.g. Cephalotaxaceae) the several scales of a cone develop into individual arils, giving the appearance of a cluster of berries. The male cones have structures called microsporangia that produce yellowish pollen through meiosis. Pollen is released and carried by the wind to female cones. Pollen grains from living pinophyte species produce pollen tubes, much like those of angiosperms. The gymnosperm male gametophytes (pollen grains) are carried by wind to
5994-453: The cone scales allows the cones to dry and open for the seeds to fall. Cones damaged by the beetles during the summer will slowly open over the next several months. Some research indicates many cones, particularly higher in the crowns, may need to be partially dried by beetle damage before fire can fully open them. The other agent is the Douglas squirrel ( Tamiasciurus douglasi ) that gnaws on
6105-424: The creation of Giant Sequoia National Monument . The wood from immature trees is less brittle, with recent tests on young plantation -grown trees showing it similar to coast redwood wood in quality. This is resulting in some interest in cultivating giant sequoia as a very high-yielding timber crop tree, both in California and also in parts of western Europe, where it may grow more efficiently than coast redwoods. In
6216-402: The dispersal of conifer seeds. Wind-born seed dispersal involves two processes, namely; local neighborhood dispersal and long-distance dispersal. Long-distance dispersal distances range from 11.9–33.7 kilometres (7.4–20.9 mi) from the source. Birds of the crow family, Corvidae , are the primary distributor of the conifer seeds. These birds are known to cache 32,000 pine seeds and transport
6327-423: The fallen seeds from ultraviolet radiation damage. Due to fire suppression efforts and livestock grazing during the early and mid-20th century, low-intensity fires no longer occurred naturally in many groves, and still do not occur in some groves today. The suppression of fires leads to ground fuel build-up and the dense growth of fire-sensitive white fir , which increases the risk of more intense fires that can use
6438-567: The female cone is termed fruit , which undergoes ripening (maturation). It was found recently that the pollen of conifers transfers the mitochondrial organelles to the embryo , a sort of meiotic drive that perhaps explains why Pinus and other conifers are so productive, and perhaps also has bearing on observed sex-ratio bias. Conifers are heterosporous , generating two different types of spores: male microspores and female megaspores . These spores develop on separate male and female sporophylls on separate male and female cones. In
6549-407: The fire started. This damage made it unable to withstand the snowstorm of January 2005, leading to the collapse of over half the trunk. In addition to fire, two animal agents also assist giant sequoia seed release. The more significant of the two is a longhorn beetle ( Phymatodes nitidus ) that lays eggs on the cones, into which the larvae then bore holes. Reduction of the vascular water supply to
6660-518: The fire’s intensity and sparing Mariposa Grove from major harm. Experts warn that to preserve healthy groves and prevent future destruction, the use of prescribed burns must increase significantly—by about 30 times the current levels. Giant sequoia is a very popular ornamental tree in many areas. It is successfully grown in most of western and southern Europe, the Pacific Northwest of North America, north to southwest British Columbia ,
6771-554: The firs as ladders to threaten mature giant sequoia crowns. Natural fires may also be important in keeping carpenter ants in check. In 1970, the National Park Service began controlled burns of its groves to correct these problems. Current policies also allow natural fires to burn. One of these untamed burns severely damaged the second-largest tree in the world, the Washington tree , in September 2003, 45 days after
SECTION 60
#17327660042816882-449: The first year spring and become conelets. The conelet goes through another winter rest and, in the spring of the second year archegonia form in the conelet. Fertilization of the archegonia occurs by early summer of the second year, so the pollination-fertilization interval exceeds a year. After fertilization, the conelet is considered an immature cone. Maturation occurs by autumn of the second year, at which time seeds are shed. In summary,
6993-429: The fleshy green scales of younger cones. The squirrels are active year-round, and some seeds are dislodged and dropped as the cone is eaten. More than 30 identified species of bird have been observed living in giant sequoia groves. The genome of the giant sequoia was published in 2020. The size of the giant sequoia genome is 8.125 Gbp (8.125 billion base pairs) which were assembled into eleven chromosome-scale scaffolds,
7104-466: The following spring. Female strobili emerge then pollination occurs in spring of the second year then the pollinated strobili become conelets in the same year (i.e. the second year). The female gametophytes in the conelet develop so slowly that the megaspore does not go through free-nuclear divisions until autumn of the third year. The conelet then overwinters again in the free-nuclear female gametophyte stage. Fertilization takes place by early summer of
7215-492: The following summer when larvae occasionally return to the surface of the wood and extend the feeding channels generally in a U-shaped configuration. During this time, small piles of frass extruded by the larvae accumulate under logs. Early in the spring of the second year following egg-laying, the larvae, about 30 mm long, pupate in the tunnel enlargement just below the wood surface. The resulting adults chew their way out in early summer, leaving round exit holes, so completing
7326-399: The fourth year and seeds mature in the cones by autumn of the fourth year. The growth and form of a forest tree are the result of activity in the primary and secondary meristems , influenced by the distribution of photosynthate from its needles and the hormonal gradients controlled by the apical meristems. External factors also influence growth and form. Fraser recorded the development of
7437-405: The giant sequoia is distinct from the coast redwood at the genus level and coined the name Sequoiadendron giganteum for it. The etymology of the genus name has been presumed—initially in The Yosemite Book by Josiah Whitney in 1868—to be in honor of Sequoyah (1767–1843), who was the inventor of the Cherokee syllabary . An etymological study published in 2012, however, concluded that the name
7548-460: The giant sequoias of Black Mountain Grove and nearby Lake Fulmor Grove are the only ones known to be reproducing and propagating free of human intervention. The conditions of the San Jacinto Mountains mimic those of the Sierra Nevada , allowing the trees to naturally propagate throughout the canyon. Giant sequoias are in many ways adapted to forest fires. Their bark is unusually fire resistant, and their cones will normally open immediately after
7659-591: The greatest diameter at breast height is the General Grant tree at 8.8 m (28.9 ft). Between 2014 and 2016, it is claimed that specimens of coast redwood were found to have greater trunk diameters than all known giant sequoias - though this has not been independently verified or affirmed in any academic literature. The trunks of coast redwoods taper at lower heights than those of giant sequoias which have more columnar trunks that maintain larger diameters to greater heights. The oldest known giant sequoia
7770-433: The greatest diameter at breast height is the General Grant tree at 8.8 m (28.9 ft). Giant sequoias are among the oldest living organisms on Earth. The oldest known giant sequoia is 3,200–3,266 years old. Wood from mature giant sequoias is fibrous and brittle; trees would often shatter after they were felled. The wood was unsuitable for construction and instead used for fence posts or match sticks. The giant sequoia
7881-419: The growing embryo) and its surrounding integument, becomes a seed . Eventually, the seed may fall to the ground and, if conditions permit, grow into a new plant. In forestry , the terminology of flowering plants has commonly though inaccurately been applied to cone-bearing trees as well. The male cone and unfertilized female cone are called male flower and female flower , respectively. After fertilization,
7992-530: The immense conifer forests of the world represent the largest terrestrial carbon sink . Conifers are of great economic value for softwood lumber and paper production. Conifer is a Latin word, a compound of conus (cone) and ferre (to bear), meaning "the one that bears (a) cone(s)". The division name Pinophyta conforms to the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN), which state (Article 16.1) that
8103-535: The largest and economically most important component group of gymnosperms, but nevertheless they comprise only one of the four groups. The division Pinophyta consists of just one class, Pinopsida, which includes both living and fossil taxa. Subdivision of the living conifers into two or more orders has been proposed from time to time. The most commonly seen in the past was a split into two orders, Taxales (Taxaceae only) and Pinales (the rest), but recent research into DNA sequences suggests that this interpretation leaves
8214-408: The largest of any organism at the time of publication. This is the first genome sequenced in the Cupressaceae family, and it provides insights into disease resistance and survival for this robust species on a genetic basis. The genome was found to contain over 900 complete or partial predicted NLR genes used by plants to prevent the spread of infection by microbial pathogens. The genome sequence
8325-571: The latter used to flavor gin . Trunk (botany) The trunk is the most important part of the tree for timber production. Trunks occur both in "true" woody plants and non-woody plants such as palms and other monocots , though the internal physiology is different in each case. In all plants, trunks thicken over time due to the formation of secondary growth , or, in monocots, pseudo-secondary growth. Trunks can be vulnerable to damage, including sunburn . Trunks which are cut down for making lumber are generally called logs ; if they are cut to
8436-417: The leaf bases are twisted to present the leaves in a very flat plane for maximum light capture. Leaf size varies from 2 mm in many scale-leaved species, up to 400 mm long in the needles of some pines (e.g. Apache pine, Pinus engelmannii ). The stomata are in lines or patches on the leaves and can be closed when it is very dry or cold. The leaves are often dark green in colour, which may help absorb
8547-402: The majority of opinion preferring retention of all the families within a single order Pinales, despite their antiquity and diverse morphology . There were seven families of conifers c. 2011 , with 65–70 genera and over 600 living species ( c. 2002 ). The seven most distinct families are linked in the box above right and phylogenetic diagram left. In other interpretations,
8658-403: The male cones, microspores are produced from microsporocytes by meiosis . The microspores develop into pollen grains, which contain the male gametophytes. Large amounts of pollen are released and carried by the wind. Some pollen grains will land on a female cone for pollination. The generative cell in the pollen grain divides into two haploid sperm cells by mitosis leading to the development of
8769-466: The names of higher taxa in plants (above the rank of family) are either formed from the name of an included family (usually the most common and/or representative), in this case Pinaceae (the pine family), or are descriptive. A descriptive name in widespread use for the conifers (at whatever rank is chosen) is Coniferae (Art 16 Ex 2). According to the ICN, it is possible to use a name formed by replacing
8880-418: The natural cycle that once relied on periodic wildfires to release seeds and clear undergrowth. Natural wildfires historically played a key role in sequoia reproduction, releasing seeds from cones and clearing undergrowth to create the open, nutrient-rich conditions needed for seedlings. Fire suppression over the last century has disrupted this cycle, limiting reproduction in many groves. Without regular fires,
8991-428: The northern faces of more southerly slopes. High levels of reproduction are not necessary to maintain the present population levels. Few groves, however, have sufficient young trees to maintain the present density of mature giant sequoias for the future. The majority of giant sequoia groves are currently undergoing a gradual decline in density since European settlement. While the present day distribution of this species
9102-456: The northwest United States , some entrepreneurs have also begun growing giant sequoias for Christmas trees . Besides these attempts at tree farming, the principal economic uses for giant sequoia today are tourism and horticulture . Giant sequoias, once primarily threatened by logging, now face their greatest danger from the absence of regular fires. Fire suppression , severe wildfires, and competition from shade-tolerant species have disrupted
9213-516: The once majestic trees broken and abandoned in formerly pristine groves, and the thought of the giants put to such modest use, spurred the public outcry that caused most of the groves to be preserved as protected land. The public can visit an example of 1880s clear-cutting at Big Stump Grove near General Grant Grove . As late as the 1980s, some immature trees were logged in Sequoia National Forest , publicity of which helped lead to
9324-486: The one 11 m tall white spruce, Fraser et al. (1964) speculated that if the photosynthate used in making apical growth in 1961 was manufactured the previous year, then the 4 million needles that were produced up to 1960 manufactured food for about 600,000 mm of apical growth or 730 g dry weight, over 12 million mm of wood for the 1961 annual ring, plus 1 million new needles, in addition to new tissue in branches, bark, and roots in 1960. Added to this would be
9435-424: The one-year and the two-year cycles differ mainly in the duration of the pollination-fertilization interval. Three-year reproductive cycle : Three of the conifer species are pine species ( Pinus pinea , Pinus leiophylla , Pinus torreyana ) which have pollination and fertilization events separated by a two-year interval. Female strobili initiated during late summer or autumn of a year, then overwinter until
9546-425: The overwintering storage capacity of stock thus treated was much improved (Eastman 1980). The concentrations of nutrients in plant tissues depend on many factors, including growing conditions. Interpretation of concentrations determined by analysis is easy only when a nutrient occurs in excessively low or occasionally excessively high concentration. Values are influenced by environmental factors and interactions among
9657-569: The paraphyletic assemblage of " walchian conifers ", which were small trees, and probably originated in dry upland habitats. The range of conifers expanded during the Early Permian ( Cisuralian ) to lowlands due to increasing aridity. Walchian conifers were gradually replaced by more advanced voltzialean or "transition" conifers. Conifers were largely unaffected by the Permian–Triassic extinction event , and were dominant land plants of
9768-411: The parent tree. Lower branches die readily from being shaded, but trees younger than 100 years retain most of their dead branches. Trunks of mature trees in groves are generally free of branches to a height of 20–50 m (70–160 ft), but solitary trees retain lower branches. The natural distribution of giant sequoias is restricted to a limited area of the western Sierra Nevada , California . As
9879-429: The photosynthate to produce energy to sustain respiration over this period, an amount estimated to be about 10% of the total annual photosynthate production of a young healthy tree. On this basis, one needle produced food for about 0.19 mg dry weight of apical growth, 3 mm wood, one-quarter of a new needle, plus an unknown amount of branch wood, bark and roots. The order of priority of photosynthate distribution
9990-561: The plant for several (2–40) years before falling, but five genera ( Larix , Pseudolarix , Glyptostrobus , Metasequoia and Taxodium ) are deciduous , shedding their leaves in autumn. The seedlings of many conifers, including most of the Cupressaceae, and Pinus in Pinaceae, have a distinct juvenile foliage period where the leaves are different, often markedly so, from the typical adult leaves. Tree rings are records of
10101-416: The pollen tube. At fertilization, one of the sperm cells unites its haploid nucleus with the haploid nucleus of an egg cell. The female cone develops two ovules, each of which contains haploid megaspores. A megasporocyte is divided by meiosis in each ovule. Each winged pollen grain is a four celled male gametophyte . Three of the four cells break down leaving only a single surviving cell which will develop into
10212-451: The removal of individual plants beyond plantations is encouraged. At least 20 species of roundheaded borers of the family Cerambycidae feed on the wood of spruce , fir , and hemlock (Rose and Lindquist 1985). Borers rarely bore tunnels in living trees, although when populations are high, adult beetles feed on tender twig bark, and may damage young living trees. One of the most common and widely distributed borer species in North America
10323-453: The same effect in 105-day-old white spruce. The general short-term effect of nitrogen fertilization on coniferous seedlings is to stimulate shoot growth more so than root growth (Armson and Carman 1961). Over a longer period, root growth is also stimulated. Many nursery managers were long reluctant to apply nitrogenous fertilizers late in the growing season, for fear of increased danger of frost damage to succulent tissues. A presentation at
10434-857: The seeds as far as 12–22 km (7.5–13.7 mi) from the source. The birds store the seeds in the soil at depths of 2–3 cm ( 3 ⁄ 4 – 1 + 1 ⁄ 4 in) under conditions which favor germination . Conifers are the dominant plants over large areas of land, most notably the taiga of the Northern Hemisphere , but also in similar cool climates in mountains further south. A number of conifers originally introduced for forestry have become invasive species in parts of New Zealand , including radiata pine ( Pinus radiata ), lodgepole pine ( P. contorta ), Douglas fir ( Pseudotsuga mensiezii ) and European larch ( Larix decidua ). In parts of South Africa , maritime pine ( Pinus pinaster ), patula pine ( P. patula ) and radiata pine have been declared invasive species. These wilding conifers are
10545-545: The seeds may be stored in closed cones for up to 60–80 years, being released only when a fire kills the parent tree. In the families Podocarpaceae , Cephalotaxaceae , Taxaceae , and one Cupressaceae genus ( Juniperus ), the scales are soft, fleshy, sweet, and brightly colored, and are eaten by fruit-eating birds, which then pass the seeds in their droppings. These fleshy scales are (except in Juniperus ) known as arils . In some of these conifers (e.g. most Podocarpaceae),
10656-448: The shoots. The giant sequoia regenerates by seed . The seed cones are 4–7 cm ( 1 + 1 ⁄ 2 –3 in) long and mature in 18–20 months, though they typically remain green and closed for as long as 20 years. Each cone has 30–50 spirally arranged scales, with several seeds on each scale, giving an average of 230 seeds per cone. Seeds are dark brown, 4–5 mm (0.16–0.20 in) long, and 1 mm (0.04 in) broad, with
10767-429: The sole source of nitrogen guanidine compounds were less prominent. Durzan and Steward noted that their results, drawn from determinations made in late summer, did not rule out the occurrence of different interim responses at other times of the year. Ammonium nitrogen produced significantly heavier (dry weight) seedlings with a higher nitrogen content after 5 weeks than did the same amount of nitrate nitrogen. Swan found
10878-731: The southern United States, southeast Australia, New Zealand and central-southern Chile . It is also grown, though less successfully, in parts of eastern North America. Trees can withstand temperatures of −31 °C (−25 °F) or colder for short periods of time, provided the ground around the roots is insulated with either heavy snow or mulch. Outside its natural range, the foliage can suffer from damaging windburn. A wide range of horticultural varieties have been selected, especially in Europe, including blue, compact blue, powder blue, hazel smith, pendulum—or weeping—varieties, and grafted cultivars. The tallest giant sequoia ever measured outside of
10989-544: The stoutest is around 12 m (39 ft) in girth and 4 m (13 ft) in diameter, in Perthshire. The Royal Botanic Gardens at Kew , and in their second campus at Wakehurst, contain multiple large specimens of the species. Biddulph Grange Garden in Staffordshire holds a fine collection of both Sequoiadendron giganteum and Sequoia sempervirens (coast redwood). The General Sherman of California has
11100-418: The stumps of more mature trees as they do on coast redwoods. Giant sequoias of all ages may sprout from their boles when branches are lost to fire or breakage. A large tree may have as many as 11,000 cones. Cone production is greatest in the upper portion of the canopy. A mature giant sequoia disperses an estimated 300,000–400,000 seeds annually. The winged seeds may fly as far as 180 m (590 ft) from
11211-517: The termination -aceae in the name of an included family, in this case preferably Pinaceae , by the appropriate termination, in the case of this division -ophyta . Alternatively, " descriptive botanical names " may also be used at any rank above family. Both are allowed. This means that if conifers are considered a division, they may be called Pinophyta or Coniferae. As a class, they may be called Pinopsida or Coniferae. As an order they may be called Pinales or Coniferae or Coniferales . Conifers are
11322-475: The tree against insect infestation and fungal infection of wounds. Fossilized resin hardens into amber , which has been commercially exploited historically (for example, in New Zealand's 19th-century kauri gum industry). The size of mature conifers varies from less than one metre to over 100 metres in height. The world's tallest, thickest, largest, and oldest living trees are all conifers. The tallest
11433-416: The usual 2-year life cycle. Conifers – notably Abies (fir), Cedrus , Chamaecyparis lawsoniana (Lawson's cypress), Cupressus (cypress), juniper , Picea (spruce), Pinus (pine), Taxus (yew), Thuja (cedar) – have been the subject of selection for ornamental purposes. Plants with unusual growth habits, sizes, and colours are propagated and planted in parks and gardens throughout
11544-468: The world. Conifers can absorb nitrogen in either the ammonium (NH 4 ) or nitrate (NO 3 ) form, but the forms are not physiologically equivalent. Form of nitrogen affected both the total amount and relative composition of the soluble nitrogen in white spruce tissues (Durzan and Steward). Ammonium nitrogen was shown to foster arginine and amides and lead to a large increase of free guanidine compounds, whereas in leaves nourished by nitrate as
11655-646: The world. The giant sequoia is listed as an endangered species by the IUCN with fewer than 80,000 remaining in its native California. The tree was introduced to the U.K. in 1853, and by now might have 5,000 mature trees growing there where it is more commonly known as Wellingtonia after the Duke of Wellington. The giant sequoia grow to an average height of 50–85 m (164–279 ft) with trunk diameters ranging from 6–8 m (20–26 ft). Record trees have been measured at 94.8 m (311 ft) tall. The specimen known to have
11766-403: The years 1955 through 1961, respectively. The total number of needles of all ages present on the 36-year-old tree in 1961 was 5.25 million weighing 14.25 kg. In 1961, needles as old as 13 years remained on the tree. The ash weight of needles increased progressively with age from about 4% in first-year needles in 1961 to about 8% in needles 10 years old. In discussing the data obtained from
11877-467: Was an invalid name under the botanical code as the name Wellingtonia had already been used earlier for another unrelated plant ( Wellingtonia arnottiana in the family Sabiaceae ). The name "Wellingtonia" has persisted in England as a common name. The following year, Joseph Decaisne transferred it to the same genus as the coast redwood, naming it Sequoia gigantea , but this name was also invalid, having been applied earlier (in 1847, by Endlicher ) to
11988-557: Was extracted from a single fertilized seed harvested from a 1,360-year-old tree specimen in Sequoia/Kings Canyon National Park identified as SEGI 21. It was sequenced over a three-year period by researchers at University of California, Davis , Johns Hopkins University , University of Connecticut , and Northern Arizona University and was supported by grants from Save the Redwoods League and
12099-512: Was more likely to have originated from the Latin sequi (meaning to follow ) since the number of seeds per cone in the newly classified genus fell in mathematical sequence with the other four genera in the suborder. John Muir wrote of the species in about 1870: "Do behold the King in his glory, King Sequoia! Behold! Behold! seems all I can say. Some time ago I left all for Sequoia and have been and am at his feet, fasting and praying for light, for
12210-588: Was planted in 1865 near the town of Camberley , Surrey , England. The trees have since been surrounded by modern real estate development. In 2024, there were 4,949 notable sequoias in the UK, with most of these trees being mature speciments. There is uncertainty if this is an undercount or overcount of the mature trees. In addition there are an estimated 500,000 Sequoiadendron giganteum and Sequoia sempervirens that are not mature. Growing conditions are generally more conducive for these trees than in their native range in
12321-462: Was the last to harvest giant sequoia, going out of business in 1924. Due to their weight and brittleness, trees would often shatter when they hit the ground, wasting much of the wood. Loggers attempted to cushion the impact by digging trenches and filling them with branches. Still, as little as 50% of the timber is estimated to have made it from groves to the mill. The wood was used mainly for shingles and fence posts, or even for matchsticks. Pictures of
#280719