In phylogenetics , basal is the direction of the base (or root) of a rooted phylogenetic tree or cladogram . The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa.
97-532: Picea sitchensis , the Sitka spruce , is a large, coniferous , evergreen tree growing to just over 100 meters (330 ft) tall, with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-largest conifer in the world (behind giant sequoia , coast redwood , kauri , and western red cedar ), and the third-tallest conifer species (after coast redwood and Himalayan cypress ). The Sitka spruce
194-604: 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
291-697: 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
388-438: A ' key innovation ' implies some degree of correlation between evolutionary innovation and diversification . However, such a correlation does not make a given case predicable, so ancestral characters should not be imputed to the members of a less species-rich basal clade without additional evidence. In general, clade A is more basal than clade B if B is a subgroup of the sister group of A or of A itself. In
485-592: A cubic meter of wood each year. Because it grows in extremely wet and poorly-drained soil, the Sitka spruce has a shallow root system with long lateral roots and few branchings. This also makes it susceptible to wind throw. DNA analysis has shown that only P. breweriana has a more basal position than Sitka spruce to the rest of the spruce. The other 33 species of spruce are more derived , which suggests that Picea originated in North America. Sitka spruce
582-422: 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
679-399: 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
776-665: 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
873-411: A lack of complexity. The terms ''deep-branching'' or ''early-branching'' are similar in meaning, and equally may misrepresent extant taxa that lie on branches connecting directly to the root node as having more ancestral character states. Despite the ubiquity of the usage of basal , systematists try to avoid its usage because its application to extant groups is unnecessary and misleading. The term
970-598: A lumber tree, and was first planted there in the 19th century. Sitka spruce plantations have become a dominant forest type in Great Britain and Ireland, making up 25% of forest cover in the former and 52% in the latter. Sitka spruce woodland is also present in France and Denmark, and the plant was introduced to Iceland and Norway in the early 20th century. Observations of Sitka spruce along the Norwegian coast have shown
1067-413: 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
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#17327800386321164-698: A mix of archaic and apomorphic (derived) features that have only been sorted out via comparison with other angiosperms and their positions within the phylogenetic tree (the fossil record could potentially also be helpful in this respect, but is absent in this case). The cladogram below is based on Ramírez-Barahona et al. (2020), with species counts taken from the source indicated. Amborellales (1 species) Nymphaeales (about 90 species) Austrobaileyales (about 95 species) Magnoliids (about 9,000 species) Chloranthales (about 80 species) Monocots (about 70,000 species) Ceratophyllales (about 6 species) Eudicots (about 175,000 species) Within
1261-880: 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),
1358-402: 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
1455-741: A remnant of the spruce forest. The largest trees were cut long before careful measurements could be made. Trees over 90 m (300 ft) tall may still be seen in Pacific Rim National Park and Carmanah Walbran Provincial Park on Vancouver Island , British Columbia (the Carmanah Giant, at 96 m (315 ft) tall, is the tallest tree in Canada), and in Olympic National Park , Washington and Prairie Creek Redwoods State Park , California (United States),
1552-487: 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
1649-406: 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
1746-473: A sister group to Homininae and are the basal genus in the great ape family Hominidae as a whole. Orangutans ( Pongo spp.) Humans ( Homo sapiens ) Chimpanzees ( Pan spp.) Gorillas ( Gorilla spp.) Subfamilies Homininae and Ponginae are both basal within Hominidae, but given that there are no nonbasal subfamilies in the cladogram it is unlikely the term would be applied to either. In general,
1843-405: A statement to the effect that one group (e.g., orangutans) is basal, or branches off first, within another group (e.g., Hominidae) may not make sense unless the appropriate taxonomic level(s) (genus, in this case) is specified. If that level cannot be specified (i.e., if the clade in question is unranked) a more detailed description of the relevant sister groups may be needed. As can be seen, the term
1940-461: A trait generally viewed as ancestral among the apes. Given that the deepest phylogenetic split in a group is likely to have occurred early in its history, identification of the most basal subclade(s) in a widely dispersed taxon or clade can provide valuable insight into its region of origin; however, the lack of additional species in a clade is not evidence that it carries the ancestral state for most traits. Most deceptively, people often believe that
2037-469: 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 ,
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#17327800386322134-591: 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
2231-446: 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
2328-418: 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
2425-576: Is found on Picea sitchensis trees in Harris Beach State Park , Oregon, USA. It provides cover and hiding places for a large variety of mammals, and good nesting and roosting habitat for birds. Sitka deer require old-growth Sitka spruce forests for winter habitat, as the extensive foliage holds a significant percentage of fallen snow in a given area, thus allowing for better understory browsing and easier migration for terrestrial animals. Cavity nesting birds favor Sitka spruce snags, and
2522-499: Is more often applied when one branch (the one deemed "basal") is less diverse than another branch (this being the situation in which one would expect to find a basal taxon of lower minimum rank). The term may be equivocal in that it also refers to the direction of the root of the tree, which represents a hypothetical ancestor; this consequently may inaccurately imply that the sister group of a more species-rich clade displays ancestral features. An extant basal group may or may not resemble
2619-466: Is native to the west coast of North America, with its northwestern limit on Kenai Peninsula , Alaska , and its southeastern limit near Fort Bragg in northern California. It is closely associated with the temperate rainforests and is found within a few kilometers of the coast in the southern portion of its range. North of Oregon, its range extends inland along river floodplains, but seldom does its range extend more than around 80 km (50 mi) from
2716-515: Is naturalized in some parts of Ireland and Great Britain, where it was introduced in 1831 by David Douglas , and New Zealand, though not so extensively as to be considered invasive . Sitka spruce is also planted extensively in Denmark, Norway, and Iceland . In Norway, Sitka spruce was introduced in the early 1900s. An estimated 50,000 hectares (120,000 acres) have been planted in Norway, mainly along
2813-515: Is not reflective of ancestral states or proximity to the common ancestor of extant species. In this example, orangutans differ from the other genera in their Asian range. This fact plus their basal status provides a hint that the most recent common ancestor of extant great apes may have been Eurasian (see below), a suggestion that is consistent with other evidence. (Of course, lesser apes are entirely Asiatic.) However, orangutans also differ from African apes in their more highly arboreal lifestyle,
2910-452: Is one of only four species documented to exceed 100 m (300 ft) in height. Its name is derived from the community of Sitka in southeast Alaska, where it is prevalent. Its range hugs the western coast of Canada and the US and continues south into northern California. The bark is thin and scaly, flaking off in small, circular plates 5–20 centimeters (2–8 in) across. The inner bark
3007-402: 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
Picea sitchensis - Misplaced Pages Continue
3104-824: Is reddish-brown. The crown is broad conic in young trees, becoming cylindric in older trees; old trees may not have branches lower than 30–40 meters (98–131 ft). The shoots are very pale buff-brown, almost white, and glabrous (hairless), but with prominent pulvini . The leaves are stiff, sharp, and needle-like, 15–25 millimeters long, flattened in cross-section, dark glaucous blue-green above with two or three thin lines of stomata , and blue-white below with two dense bands of stomata. The cones are pendulous, slender cylindrical, 6–10 cm ( 2 + 1 ⁄ 2 –4 in) long and 2 cm ( 3 ⁄ 4 in) broad when closed, opening to 3 cm ( 1 + 1 ⁄ 4 in) broad. They have thin, flexible scales 15–20 mm ( 5 ⁄ 8 – 3 ⁄ 4 in) long;
3201-454: Is represented. In phylogenetics, the term basal cannot be objectively applied to clades of organisms, but tends to be applied selectively and more controversially to groups or lineages thought to possess ancestral characters, or to such presumed ancestral traits themselves. In describing characters, "ancestral" or " plesiomorphic " are preferred to "basal" or " primitive ", the latter of which may carry false connotations of inferiority or
3298-728: Is sacred to the Haida First Nations people. It was illegally felled in 1997 by Grant Hadwin , although saplings grown from cuttings can now be found near its original site. In the Lushootseed language , spoken in what is now Washington state , it is known as c̓əlaqayac. The stilbene glucosides astringin , isorhapontin , and piceid can be found in the bark of the Sitka spruce. In the Olympic National Forest in Washington, Sitka spruce trees near
3395-432: 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
3492-556: Is thus very susceptible. Sitka spruce forests have a fire regime of severe crown or surface fires on long intervals, (150 to 350+ years) which results in total stand replacement. Sitka spruce recolonizes burned sites via wind-dispersed seed from adjacent unburned forests. The root bark of Sitka spruce trees is used in Native Alaskan basket-weaving designs and for rain hats. The pitch was used for caulking , chewing, and its medicinal properties. Native Americans heated and plied
3589-623: 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
3686-583: 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
3783-743: 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
3880-678: 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 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
3977-590: The great apes , gorillas (eastern and western) are a sister group to chimpanzees , bonobos and humans . These five species form a clade, the subfamily Homininae (African apes), of which Gorilla has been termed the basal genus. However, if the analysis is not restricted to genera, the Homo plus Pan clade is also basal. Humans ( Homo sapiens ) Bonobos ( Pan paniscus ) Chimpanzees ( Pan troglodytes ) Eastern gorillas ( Gorilla beringei ) Western gorillas ( Gorilla gorilla ) Moreover, orangutans are
Picea sitchensis - Misplaced Pages Continue
4074-460: 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
4171-499: The last common ancestor of a larger clade to a greater degree than other groups, and is separated from that ancestor by the same amount of time as all other extant groups. However, there are cases where the unusually small size of a sister group does indeed correlate with an unusual number of ancestral traits, as in Amborella (see below). This is likely a source of the mis-use of the term. Other famous examples of this phenomenon are
4268-430: The oviparous reproduction and nipple-less lactation of monotremes , a clade of mammals with just five species, and the archaic anatomy of the tuatara , a basal clade of lepidosaurian with a single species. The flowering plant family Amborellaceae , restricted to New Caledonia in the southwestern Pacific, is a basal clade of extant angiosperms , consisting of the most species, genus, family and order within
4365-402: 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,
4462-472: The "most remote tree in the world". Sitka spruce provides critical habitat for a large variety of mammals, birds, reptiles, and amphibians. Its thick, sharp needles are poor browse for ungulates , and only the new spring growth is eaten. However, in Alaska and British Columbia the needles of Picea sitchensis comprise up to 90% of the winter diet of blue grouse . Lichen -forming fungi Helocarpon lesdainii
4559-409: 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
4656-743: 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
4753-570: The Pacific Ocean and its inlets. It is situated at about 2,500 m (8,200 ft) above sea level in Alaska and generally below 450 m (1,480 ft) further south. Forests with the species average between 200 and 500 cm (79 and 197 in) of rain annually. It is tolerant to salty spray common in coastal dune habitat, such as at Cape Disappointment State Park in Washington, and prefers soils high in magnesium, calcium, and phosphorus. Sitka spruce has been introduced to Europe as
4850-467: The Pacific Ocean. Another specimen, from Klootchy Creek Park , Oregon, was previously recorded to be the largest with a circumference of 15 metres (49 ft) and height of 66 metres (217 ft). Sitka spruce is a long-lived tree, with individuals over 700 years old known. Because it grows rapidly under favorable conditions, large size may not indicate exceptional age. The Queets Spruce has been estimated to be only 350 to 450 years old, but adds more than
4947-464: 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
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#17327800386325044-558: 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
5141-407: The bracts just above the scales are the longest of any spruce, occasionally just exserted and visible on the closed cones. They are green or reddish, maturing pale brown 5–7 months after pollination. The seeds are black, 3 mm ( 1 ⁄ 8 in) long, with a slender, 7–9 mm ( 1 ⁄ 4 – 3 ⁄ 8 in) long pale brown wing. More than a century of logging has left only
5238-489: The coast from Vest-Agder in the south to Troms in the north. It is more tolerant to wind and saline ocean air, and grows faster than the native Norway spruce . But in Norway, the Sitka spruce is now considered an invasive species, and effort to eliminate it is being made. The resonant wood is used widely in piano, harp , violin, and guitar manufacture, as its high strength-to-weight ratio and regular, knot-free rings make it an excellent conductor of sound. For these reasons,
5335-587: 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
5432-399: The context of large groups, the term "basal" is often used loosely to refer to positions closer to the root than the majority, and in such cases, expressions like "very basal" can appear. A 'core clade' refers to the grouping that encompasses all constituent clades except for the basal clade(s) of the lowest rank within a larger clade, exemplified by core eudicots . No extant taxon is closer to
5529-437: The diagram. It is often assumed in this example that the terminal branches of the cladogram depict all the extant taxa of a given rank within the clade; this is one reason the term basal is highly deceptive, as the lack of additional species in one clade is taken as evidence of morphological affinity with ancestral taxa. Additionally, this qualification does not ensure that the diversity of extinct taxa (which may be poorly known)
5626-402: 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
5723-567: 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
5820-449: 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,
5917-466: 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
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#17327800386326014-492: 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
6111-399: 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
6208-447: The group that are sister to all other angiosperms (out of a total of about 250,000 angiosperm species). The traits of Amborella trichopoda are regarded as providing significant insight into the evolution of flowering plants; for example, it has "the most primitive wood (consisting only of tracheids ), of any living angiosperm" as well as "simple, separate flower parts of indefinite numbers, and unsealed carpels". However, those traits are
6305-419: 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,
6402-530: 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
6499-535: 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
6596-514: The latter of which houses the tallest individual measuring at 100.2 meters or 329 feet tall; two others at the last site are just over 96 m tall. The Queets Spruce is the largest in the world with a trunk volume of 346 m (12,200 cu ft), a height of 74.6 m (244 ft 9 in), and a 4.4 m (14 ft 5 in) dbh . It is located near the Queets River in Olympic National Park , about 26 km (16 mi) from
6693-433: The latter used to flavor gin . Basal (phylogenetics) While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank , species diversity , or both. If C is a basal clade within D that has the lowest rank of all basal clades within D , C may be described as the basal taxon of that rank within D . The concept of
6790-417: 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
6887-402: 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,
6984-403: 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
7081-466: 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
7178-449: The ocean sometimes develop burls . According to a guidebook entitled Olympic Peninsula , "Damage to the tip or the bud of a Sitka spruce causes the growth cells to divide more rapidly than normal to form this swelling or burl. Even though the burls may look menacing, they do not affect the overall tree growth." Conifer Conifers are a group of cone-bearing seed plants , a subset of gymnosperms . Scientifically, they make up
7275-486: 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
7372-424: 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
7469-425: 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
7566-569: 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
7663-429: 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
7760-561: 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
7857-416: 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
7954-451: 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
8051-422: The root than any other. A basal group in the stricter sense forms a sister group to the rest of the larger clade, as in the following case: Basal clade #1 Non-basal clade #1 Non-basal clade #2 Non-basal clade #3 While it is easy to identify a basal clade in such a cladogram, the appropriateness of such an identification is dependent on the accuracy and completeness of
8148-478: The roots to make cord. The resin was used as glue and for waterproofing. Natives and pioneers split off shakes for construction use. The wood is light and relatively strong. Sitka spruce is of major importance in forestry for timber and paper production. Outside its native range, it is particularly valued for its fast growth on poor soils and exposed sites where few other trees can prosper; in ideal conditions, young trees may grow 1.5 m (5 ft) per year. It
8245-453: 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
8342-927: 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
8439-545: 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),
8536-429: 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
8633-543: The species to be growing 25–100% faster than the native Norway spruce there, even as far north as Vesterålen , and Sitka spruces planted along the southwest coast of Norway are growing fastest among the Sitka plantations in Europe. A 9-metre-tall, 100-year-old Sitka spruce growing in the middle of the permanently uninhabited sub-antarctic Campbell Island has been recognised by the Guinness World Records as
8730-517: 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
8827-570: The total number of species is relatively small, conifers are ecologically important. They 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. 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,
8924-475: 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
9021-502: The tree is used by bald eagles , and peregrine falcons as nesting habitat. Sitka spruce is shade tolerant but not as much as its competitors, preferring full sun if possible. It is a pioneer on landslides, sand dunes, uplifted beaches, and deglaciated terrain. However, it is a climax species in coastal forests, where it can become dominant. Due to the prevalence of Sitka spruce in cool, wet climates, its thin bark and shallow root system are not adapted to resist fire damage and it
9118-416: 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
9215-637: The wood is also an important material for sailboat spars , and aircraft wing spars (including flying models). The Wright brothers ' Flyer was built using Sitka spruce, as were many aircraft before World War II ; during that war, aircraft such as the British Mosquito used it as a substitute for strategically important aluminium. Newly grown tips of Sitka spruce branches are used to flavor spruce beer and are boiled to make syrup . A unique specimen with golden foliage that used to grow on Haida Gwaii , known as Kiidk'yaas or "The Golden Spruce",
9312-468: 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
9409-403: 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
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