Conifer: Difference between revisions
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{{Short description|Group of | {{Short description|Group of seed plants}} | ||
{{good article}} | |||
{{Other uses}} | {{Other uses}} | ||
{{Use dmy dates|date=June 2022}} | {{Use dmy dates|date=June 2022}} | ||
{{ | {{Use British English|date=September 2025}} | ||
{{Automatic taxobox | {{Automatic taxobox | ||
| fossil_range = {{fossil range|307|0}}[[Carboniferous]]–[[Holocene|Present]] | | fossil_range = {{fossil range|307|0}}[[Carboniferous]]–[[Holocene|Present]] | ||
| image = Sapins pectinés.jpg | | image = Sapins pectinés.jpg | ||
| image_caption = Large conifer [[forest]] | | image_alt = Conifer forest | ||
| image_caption = Large conifer [[forest]] of silver fir (''[[Abies alba]]'') at [[Vosges]], Eastern [[France]] | |||
| display_parents = 2 | | display_parents = 2 | ||
| taxon = Pinopsida | | taxon = Pinopsida | ||
| Line 30: | Line 32: | ||
* [[Palissyales]] † | * [[Palissyales]] † | ||
* [[Voltziales]] † | * [[Voltziales]] † | ||
*[[Cordaitales]] † | * [[Cordaitales]] † | ||
| synonyms = * Coniferophyta | | synonyms = * Coniferophyta | ||
* Coniferae | * Coniferae | ||
| Line 36: | Line 38: | ||
}} | }} | ||
'''Conifers''' ({{ | '''Conifers''' ({{IPAc-en|ˈ|k|ɒ|n|ɪ|f|ər}}) are a group of [[Spermatophyte|seed plants]], a subset of [[gymnosperm]]s. They are mainly [[evergreen]] trees with a regular branching pattern, reproducing with male and female [[conifer cone|cones]], usually [[monoecy|on the same tree]]. They are [[wind-pollinated]] and the seeds are usually dispersed by the wind. | ||
Scientifically, they make up the [[phylum|division]] '''Pinophyta''', also known as '''Coniferae'''. All [[Neontology|extant]] conifers except for the [[Gnetophytes]] are [[perennial plant|perennial]] [[woody plant]]s with [[secondary growth]].<!--<ref name="Campbell-2005">--> There are over 600 living species. | |||
Conifers first appear in the fossil record over 300 million years ago in the [[Carboniferous]]. They became dominant land plants in the [[Mesozoic]], until [[flowering plants]] took over many ecosystems in the [[Cretaceous]]. Many conifers today are [[Relict (biology)|relict species]], surviving in a small part of their former ranges. Such relicts include ''[[Wollemia]]'', known only from a small area of Australia, and ''[[Metasequoia glyptostroboides]]'', known from Cretaceous fossils and surviving in a small area of China. | |||
Although the total number of species is relatively small, conifers are [[ecology|ecologically]] important. They are the dominant plants over the [[taiga]] of the [[Northern Hemisphere]]. Boreal conifers have multiple adaptations to survive winters, including a conical shape to shed snow, strong tracheid vessels to tolerate ice pressure, and a waxy covering on the needle leaves to minimise water loss. Several fungi form [[ectomycorrhiza]]l associations with conifers. Other fungi cause diseases such as [[needle cast]], especially harmful to young trees. Conifers are affected by pest insects such as wood-boring [[longhorn beetle]]s and by [[bark beetle]]s, which make galleries just under the bark. Conifers are of great economic value for [[timber]] and [[paper]] production. | |||
== Evolution == | |||
The | === Fossil history === | ||
The earliest conifers appear in the fossil record during the Late [[Carboniferous]] ([[Pennsylvanian (geology)|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 the paraphyletic assemblage of "[[Walchia|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 [[Voltziales|voltzialean]] or "transition" conifers.<ref name="Feng-2017">{{Cite journal |last=Feng |first=Zhuo |date=September 2017 |title=Late Palaeozoic plants |journal=[[Current Biology]] |volume=27 |issue=17 |pages=R905–R909 |bibcode=2017CBio...27.R905F |doi=10.1016/j.cub.2017.07.041 |pmid=28898663 |doi-access=free}}</ref> Conifers were largely unaffected by the [[Permian–Triassic extinction event]],<ref>{{Cite journal |last1=Nowak |first1=Hendrik |last2=Schneebeli-Hermann |first2=Elke |last3=Kustatscher |first3=Evelyn |date=2019-01-23 |title=No mass extinction for land plants at the Permian–Triassic transition |journal=[[Nature Communications]] |volume=10 |issue=1 |page=384 |bibcode=2019NatCo..10..384N |doi=10.1038/s41467-018-07945-w |pmc=6344494 |pmid=30674875 |doi-access=free}}</ref> and were dominant land plants of the [[Mesozoic]] era. Modern groups of conifers emerged from the Voltziales during the Late Permian through [[Jurassic]].<ref name="Leslie-2018">{{Cite journal |last1=Leslie |first1=Andrew B. |last2=Beaulieu |first2=Jeremy |last3=Holman |first3=Garth |last4=Campbell |first4=Christopher S. |last5=Mei |first5=Wenbin |last6=Raubeson |first6=Linda R. |last7=Mathews |first7=Sarah |date=September 2018 |title=An overview of extant conifer evolution from the perspective of the fossil record |journal=[[American Journal of Botany]] |language=en |volume=105 |issue=9 |pages=1531–1544 |doi=10.1002/ajb2.1143 |pmid=30157290 |doi-access=free}}</ref> Conifers underwent a major decline in the [[Late Cretaceous]] corresponding to the explosive [[adaptive radiation]] of [[flowering plant]]s.<ref>{{cite journal |last1=Condamine |first1=Fabien L. |last2=Silvestro |first2=Daniele |last3=Koppelhus |first3=Eva B. |last4=Antonelli |first4=Alexandre |title=The rise of angiosperms pushed conifers to decline during global cooling |journal=[[Proceedings of the National Academy of Sciences of the United States of America]] |date=17 November 2020 |volume=117 |issue=46 |pages=28867–28875 |doi=10.1073/pnas.2005571117 |bibcode=2020PNAS..11728867C |pmc=7682372 |pmid=33139543 |doi-access=free }}</ref> | |||
<gallery class=center mode=nolines widths=180 heights=180> | |||
File:Conifer fossil.jpg|[[Voltziales]]: ''[[Walchia|Walchia laxifolia]]'' foliage, [[Cisuralian]], Germany | |||
File:Araucaria mirabilis (fossil cone) (Jurassic; Argentina) (49021443726).jpg|''Araucaria'' cone, [[Jurassic]], Argentina | |||
File:Elatides sp. (fossil conifer) (Judith River Group, Upper Cretaceous; Montana or Canada) (25210755717).jpg|''Elatides'' foliage, [[Late Cretaceous]], N. America | |||
File:Σίγρι1.jpg|Base of conifer trunk with roots, [[Early Miocene]], [[Lesbos]], Greece | |||
</gallery> | |||
=== Relict species === | |||
Several [[Neontology|extant]] conifers have [[relict taxon]] status, surviving in small areas or in very small numbers where they once may have been common and widespread. One such is ''[[Wollemia nobilis]]'', discovered in 1994 in some narrow, steep-sided, [[sandstone]] [[gorge]]s in Australia.<ref>{{cite web |title=Wollemia nobilis: The Australian Botanic Garden, Mount Annan – April |url=https://www.rbgsyd.nsw.gov.au/annan/the_garden/Plant_of_the_Month/wollemia_nobilis |archive-url=https://web.archive.org/web/20151019130835/https://www.rbgsyd.nsw.gov.au/annan/the_garden/Plant_of_the_Month/wollemia_nobilis |archive-date=19 October 2015 |access-date=30 October 2015 |publisher=[[Royal Botanic Garden, Sydney]]}}</ref> The wild population consisted of under 60 adult trees with essentially no genetic variability, implying a genetic bottleneck some thousands of years ago.<ref>{{cite report |last1=Stevenson |first1=Dennis Wm. |last2=Ramakrishnan |first2=Srividya |last3=Alves |first3=Cristiane de Santis |last4=Coelho |first4=Laís Araujo |last5=Kramer |first5=Melissa |last6=Goodwin |first6=Sara |last7=Ramos |first7=Olivia Mendevil |last8=Eshel |first8=Gil |last9=Sondervan |first9=Veronica M. |last10=Frangos |first10=Samantha |display-authors=6 |year=2023 |title=The genome of the Wollemi pine, a critically endangered "living fossil" unchanged since the Cretaceous, reveals extensive ancient transposon activity |type=preprint |pmid=37662366 |pmc=10473749 |doi=10.1101/2023.08.24.554647 |url=https://www.biorxiv.org/content/10.1101/2023.08.24.554647v1.full |access-date=2023-09-15 |url-status=live |archive-url=https://web.archive.org/web/20230916150916/https://www.biorxiv.org/content/10.1101/2023.08.24.554647v1.full |archive-date=2023-09-16}}</ref> The extant [[gnetophyte]]s consist of three relict genera, namely ''[[Ephedra (plant)|Ephedra]]'', ''[[Gnetum]]'', and ''[[Welwitschia]]''. Fossils definitely of the group date back to the [[Late Jurassic]], with many species in the Cretaceous.<ref name="Coiro-2022">{{Cite journal |last1=Coiro |first1=Mario |last2=Roberts |first2=Emily A. |last3=Hofmann |first3=Christa-Ch. |last4=Seyfullah |first4=Leyla J. |date=14 December 2022 |title=Cutting the long branches: Consilience as a path to unearth the evolutionary history of Gnetales |journal=[[Frontiers in Ecology and Evolution]] |volume=10 |article-number=1082639 |doi=10.3389/fevo.2022.1082639 |doi-access=free }}</ref> Conifers as a whole, too, declined markedly after the angiosperms (flowering plants) diversified during the Cretaceous, coming to dominate most [[terrestrial ecosystem]]s. Many conifer species became [[Extinction|extinct]], leaving 30 out of 80 genera with just one extant species, and 11 more with just two or three species. The popular phrase "[[living fossil]]s" could, the Dutch botanist [[Aljos Farjon]] states, fittingly be applied to many of these. Thus, ''[[Metasequoia glyptostroboides]]'', the dawn redwood, is known from fossils of Late Cretaceous and [[Miocene]] age, and was found also as an extant tree with a small relict range in China.<ref name="Farjon 1999"/> | |||
== | <gallery class=center mode=nolines widths=180 heights=180> | ||
File:Wakehurst Place woodland Wollemi pine.jpg|''[[Wollemia nobilis]]'' is a [[relict taxon]] known only from a small area in Australia. | |||
File:Welwitschia at Ugab River basin.jpg|''[[Welwitschia mirabilis]]'' is one of the [[gnetophyte]]s, all relict taxa very unlike other conifers. | |||
File:Metasequoia glyptostroboides Autumn leaf color.jpg|''[[Metasequoia glyptostroboides]]'' survives in a small part of China, and is known from [[fossil]]s from the [[Late Cretaceous]] onwards. | |||
</gallery> | |||
=== External phylogeny=== | |||
The cladogram summarizes the group's external phylogeny. The conifers are [[gymnosperm]]s, sister to a [[clade]] consisting of the [[Ginkgoidae|ginkgos]] and [[Cycadidae|cycads]].<ref name="Leslie 2018">{{Cite journal |last=Leslie |first=Andrew B. |last2=Beaulieu |first2=Jeremy |last3=Holman |first3=Garth |last4=Campbell |first4=Christopher S. |last5=Mei |first5=Wenbin |last6=Raubeson |first6=Linda R. |last7=Mathews |first7=Sarah |display-authors=et al. |year=2018 |title=An overview of extant conifer evolution from the perspective of the fossil record |journal=[[American Journal of Botany]] |volume=105 |issue=9 |pages=1531–1544 |doi=10.1002/ajb2.1143 |pmid=30157290 |s2cid=52120430}}</ref><ref name="Leslie appendix">{{Cite journal |last=Leslie |first=Andrew B. |display-authors=et al. |year=2018 |title=ajb21143-sup-0004-AppendixS4 |url=https://bsapubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2Fajb2.1143&file=ajb21143-sup-0004-AppendixS4.pdf |journal=[[American Journal of Botany]] |volume=105 |issue=9 |pages=1531–1544 |doi=10.1002/ajb2.1143 |pmid=30157290 |s2cid=52120430}}</ref><ref name="Stull 2021">{{Cite journal |last=Stull |first=Gregory W. |last2=Qu |first2=Xiao-Jian |last3=Parins-Fukuchi |first3=Caroline |last4=Yang |first4=Ying-Ying |last5=Yang |first5=Jun-Bo |last6=Yang |first6=Zhi-Yun |last7=Hu |first7=Yi |last8=Ma |first8=Hong |last9=Soltis |first9=Pamela S. |last10=Soltis |first10=Douglas E. |last11=Li |first11=De-Zhu |last12=Smith |first12=Stephen A. |last13=Yi |first13=Ting-Shuang |display-authors=et al. |year=2021 |title=Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms |url=https://www.nature.com/articles/s41477-021-00964-4 |journal=[[Nature Plants]] |volume=7 |issue=8 |pages=1015–1025 |bibcode=2021NatPl...7.1015S |biorxiv=10.1101/2021.03.13.435279 |doi=10.1038/s41477-021-00964-4 |pmid=34282286 |s2cid=232282918}}</ref><ref name="Stull matrix">{{Cite report |url=https://figshare.com/articles/dataset/Gene_duplications_and_genomic_conflict_underlie_major_pulses_of_phenotypic_evolution_in_gymnosperms/14547354 |title=main.dated.supermatrix.tree.T9.tre |last=Stull |first=Gregory W. |year=2021 |publisher=Figshare |doi=10.6084/m9.figshare.14547354.v1 |display-authors=et al.}}</ref> | |||
{{clade | |||
|label1=[[Gymnosperm]]s | |||
|1={{clade | |||
|1={{clade | |||
|1=[[Ginkgoidae]] [[File:Addisonia (PLATE 362) - colored illustrations and popular descriptions of plants (1916-(1964)) (16150512234).jpg|60px]] | |||
|2=[[Cycadidae]] [[File:Cycas circinalis(draw).jpg|60px]] | |||
}} | |||
|2='''Conifers''' [[File:Abies alba - Köhler–s Medizinal-Pflanzen-001.jpg|60px]] | |||
}} | |||
}} | |||
=== Internal phylogeny === | |||
The | The [[Gnetophyta]], despite their distinct appearances, were long viewed as outside the conifer group, but phylogenomic analysis indicates that they are part of the conifer clade, sister to the pine family (the 'gnepine' hypothesis). If so, the gnetophytes once shared the distinctive characters of the conifers, and have lost them.<ref name="Chaw 1997">{{cite journal |last1=Chaw |first1=S. M. |last2=Aharkikh |first2=A. |last3=Sung |first3=H. M. |last4=Lau |first4=T. C. |last5=Li |first5=W. H. |year=1997 |title=Molecular phylogeny of extant gymnosperms and seed plant evolution: Analysis of nuclear 18S rRNA sequences |journal=[[Molecular Biology and Evolution]] |volume=14 |issue=1 |pages=56–68 |pmid=9000754 |doi=10.1093/oxfordjournals.molbev.a025702 |doi-access=free}}</ref> The cladogram summarizes the conifers' internal phylogeny:<ref name="Ran 2018">{{cite journal |last1=Ran |first1=Jin-Hua |last2=Shen |first2=Ting-Ting |last3=Wang |first3=Ming-Ming |last4=Wang |first4=Xiao-Quan |title=Phylogenomics resolves the deep phylogeny of seed plants and indicates partial convergent or homoplastic evolution between Gnetales and angiosperms |journal=[[Proceedings of the Royal Society B: Biological Sciences]] |volume=285 |issue=1881 |date=27 June 2018 |pmid=29925623 |pmc=6030518 |doi=10.1098/rspb.2018.1012 |doi-access=free |article-number=20181012 |url=https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2018.1012 |access-date=20 September 2025}}</ref> | ||
{{clade|style=line-height:100%; | {{clade|style=line-height:100%; | ||
|label1='''Pinophyta''' | |||
|sublabel1=(Coniferae) | |||
|1={{clade | |1={{clade | ||
|1 | |1={{clade | ||
|1={{clade | |1={{clade | ||
|1=[[ | |label1=[[Pinaceae]] |sublabel1=pine family | ||
|2=[[ | |1=[[File:Abies alba - Köhler–s Medizinal-Pflanzen-001.jpg|60px]] | ||
|label2=[[Gnetophyta]] |sublabel2=(3 relict genera) | |||
|2=[[File:Gnetum gnemon.jpg|60px]] | |||
}} | }} | ||
|2={{clade | |2={{clade | ||
|1=[[ | |1={{clade | ||
|label1=[[Araucariaceae]] |sublabel1=monkey puzzle family | |||
|1=[[File:Araucaria brasiliana SZ138.jpg|60px]] | |||
|label2=[[Podocarpaceae]] |sublabel2=podocarps | |||
|2=[[File:Podocarpus macrophyllus SZ134.png|60px]] | |||
}} | |||
|2={{clade | |2={{clade | ||
|1=[[ | |label1=[[Sciadopityaceae]] |sublabel1=umbrella pines | ||
|1=[[File:Sciadopitys verticillata SZ102.jpg|60px]] | |||
|2={{clade | |2={{clade | ||
|1=[[ | |label1=[[Cupressaceae]] |sublabel1=cypress family | ||
|2=[[Taxaceae]] | |1=[[File:Cupressus sempervirens (cropped).tiff|60px]] | ||
|2={{clade | |||
|label1=[[Cephalotaxaceae]] |sublabel1=plum yew family | |||
|1=[[File:Die winterharten Nadelhölzer Mitteleuropas - ein Handbuch für Gärtner und Gartenfreunde (1909) (20959624281).jpg|50px]] | |||
|label2=[[Taxaceae]] |sublabel2=yew family | |||
|2=[[File:Nouvelle iconographie fourragère (cropped).jpg|60px]] | |||
}} | |||
}} | }} | ||
}} | }} | ||
| Line 79: | Line 124: | ||
}} | }} | ||
=== Taxonomy === | |||
[[ | The name ''conifer'', meaning 'cone-bearing', derives from Latin {{lang|la|laconus}} (cone) and {{lang|la|ferre}} (to bear).<ref>{{cite web |title=Conifer (n.) |url=https://www.etymonline.com/word/conifer |publisher=[[Online Etymology Dictionary]] |access-date=23 April 2025}}</ref> As recently as 1999, the botanist [[Aljos Farjon]] wrote that while the Coniferae had up to the early 20th century been considered "a natural family",<ref name="Farjon 1999"/><!--p. 159--> comparable to the [[Rosaceae]], he doubted that the conifers or the gymnosperms formed natural groups ([[clade]]s).<ref name="Farjon 1999"/><!--p. 160--> By 2016, the conifers were recognised as a clade, with six families (not including the gnetophytes),<ref name="GymnoData">{{cite web |url=http://www.conifers.org/zz/pinales.htm |title=Pinidae (conifers) description – The Gymnosperm Database |archive-url=https://web.archive.org/web/20160220110331/http://www.conifers.org/zz/pinales.htm|archive-date=2016-02-20}}</ref> 65–70 genera, and over 600 living species ({{Circa|2002|lk=no}}).<ref name="Judd-2002">{{cite book |last1=Judd |first1=W. S. |title=Plant systematics, a phylogenetic approach |last2=Campbell |first2=C. S. |last3=Kellogg |first3=E. A. |last4=Stevens |first4=P. F. |last5=Donoghue |first5=M. J. |date=2002 |publisher=[[Sinauer Associates]] |isbn=0-87893-403-0 |edition=2nd |location=Sunderland, Massachusetts}}</ref>{{rp|205}}<ref>{{cite journal |last1=Lott |first1=John N. A. |last2=Liu |first2=Jessica C. |last3=Pennell |first3=Kelly A. |last4=Lesage |first4=Aude |last5=West |first5=M Marcia |year=2002 |title=Iron-rich particles and globoids in embryos of seeds from phyla Coniferophyta, Cycadophyta, Gnetophyta, and Ginkgophyta: characteristics of early seed plants |journal=[[Canadian Journal of Botany]] |volume=80 |issue=9 |pages=954–961 |doi=10.1139/b02-083 |bibcode=2002CaJB...80..954L }}</ref><ref>{{cite book |last1=Díaz-Sala |first1=Carmen |last2=Cabezas |first2=José Antonio |last3=de Simón |first3=Brígida Fernández |last4=Abarca |first4=Dolores |last5=Guevara |first5=M. Ángeles |last6=de Miguel |first6=Marina |last7=Cadahía |first7=Estrella |last8=Aranda |first8=Ismael |last9=Cervera |first9=María-Teresa |display-authors=5 |title=From Plant Genomics to Plant Biotechnology |chapter=The uniqueness of conifers |publisher=[[Elsevier]] |year=2013 |isbn=978-1-907568-29-9 |doi=10.1533/9781908818478.67 |page=67–96}}</ref> Depending on interpretation, the [[Cephalotaxaceae]] may or may not be included within the Taxaceae, while some authors recognize [[Phyllocladus|Phyllocladaceae]] as distinct from Podocarpaceae. The family [[Taxodiaceae]] is here included in the family Cupressaceae.<ref name="Christenhusz-2011">{{cite journal |last1=Christenhusz |first1=M. J. M. |last2=Reveal |first2=J. |last3=Farjon |first3=Aljos |author3-link=Aljos Farjon |last4=Gardner |first4=M. F. |last5=Mill |first5=R. R. |last6=Chase |first6=M. W. |year=2011 |title=A new classification and linear sequence of extant gymnosperms |journal=[[Phytotaxa]] |volume=19 |issue=1 |pages=55–70 |doi=10.11646/phytotaxa.19.1.3 |bibcode=2011Phytx..19...55C }}</ref> | ||
== | == Description == | ||
All living conifers (except the gnetophytes) are woody plants, and most are trees with narrow leaves, often needle-like. There are separate male and female reproductive structures, the cones. Pollination is always by wind; the seeds are mostly winged. The trees have a regular branching pattern. Many conifers have distinctly scented [[resin]].<ref name="Mitchell 1985">{{cite book |last1=Mitchell |first1=Alan F. |last2=Edlin |first2=Herbert L. |author-link2=Herbert L. Edlin |title=Conifers: Forestry Commission Booklet No. 15 |year=1985 |orig-date=1966 |edition=3rd |publisher=[[HMSO]] |pages=4–5 |url=https://cdn.forestresearch.gov.uk/1985/03/fcbk015_3ed.pdf |isbn=978-0-11-710040-4}}</ref> | |||
The world's tallest and oldest living trees are conifers. The tallest is a [[Sequoia sempervirens|coast redwood]] (''Sequoia sempervirens''), with a height of {{convert|116.07|m|ft}}.<ref name="Ghose">{{cite news |last=Ghose |first=Tia |date=May 23, 2022 |title=What is the world's tallest tree? |url=https://www.livescience.com/28729-tallest-tree-in-world.html |publisher=[[LiveScience]]}}</ref> Among the smallest conifers is the [[Lepidothamnus laxifolius|pygmy pine]] (''Lepidothamnus laxifolius'') of New Zealand, which is seldom taller than 30 cm when mature.<ref>{{cite web |last=Wassilieff |first=Maggy |title=Conifers |publisher=[[Te Ara: The Encyclopedia of New Zealand]] |date=1 Mar 2009 |url=http://www.teara.govt.nz/en/conifers/6/5 |access-date=17 December 2012 |archive-date=1 March 2010 |archive-url=https://web.archive.org/web/20100301031106/http://www.teara.govt.nz/en/conifers/6/5 |url-status=live }}</ref> The oldest non-clonal living tree is a Great Basin bristlecone pine (''[[Pinus longaeva]]''), 4,700 years old.<ref name="Dallimore 1967">{{cite book |last1=Dallimore |first1=W. |last2=Jackson |first2=A. B. |last3=Harrison |first3=S. G. |year=1967 |title=A handbook of Coniferae and Ginkgoaceae |edition=4th |location=New York |publisher=[[St. Martin's Press]] |page=xix}}</ref> | |||
[[wikt:Boreal|Boreal]] conifers have multiple [[adaptation]]s to survive winters, including the tree's conical shape to shed snow, strong tracheid vessels to tolerate ice pressure, and a waxy covering on the needle leaves to minimise water loss.<ref name="Michigan">{{cite web |title=Winter Adaptations of Trees |url=https://mff.forest.mtu.edu/Environment/WinterTrees.htm |publisher=[[Michigan Technological University]] |access-date=20 September 2025}}</ref> | |||
== | <gallery class=center mode=nolines widths=200 heights=200> | ||
File:US 199 Redwood Highway.jpg|Tallest: ''[[Sequoia sempervirens]]'' can reach a height of {{convert|116.07|m|ft}}.<ref name="Ghose"/> | |||
File:Big_bristlecone_pine_Pinus_longaeva.jpg|Oldest: ''[[Pinus longaeva]]'' can reach an age of 4,700 years.<ref name="Dallimore 1967"/> | |||
File:Snow falling at Tower (f6d906ff-4e12-4375-97d6-a21bedf95d8b).jpg|The narrow conical shape of [[wikt:Boreal|boreal]] conifers, and their downward-drooping limbs, help them shed snow.<ref name="Michigan"/> | |||
</gallery> | |||
=== Foliage === | |||
[[ | Most conifers are evergreens.<ref name="Campbell-2005">{{cite book |last=Campbell |first=Reece |chapter=Phylum Coniferophyta |title=Biology |edition=7th |year=2005 |page=595}}</ref> In many species such as pines, firs, and [[cedrus|cedar]]s, the [[leaf|leaves]] are long, thin and needle-like. Others like [[Cupressaceae|cypresses]] have flat, triangular scale-like leaves.<ref>{{cite web |title=Conifer Tree ID by Leaf and Needle Shape |url=https://www.treeguideuk.co.uk/conifer-key/ |website=Treeguide |access-date=20 September 2025}}</ref> 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 [[Decussation|decussate]] opposite pairs or [[Whorl (botany)|whorl]]s of 3 or 4. In many species with spirally arranged leaves, such as ''[[Abies grandis]]'', 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 [[stoma]]ta 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 a maximum of energy from weak sunshine at high [[latitude]]s or under forest canopy shade. Conifers from lower latitudes 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 remain on the plant for several (2–40) years before falling, but five genera (''[[larch|Larix]]'', ''[[Pseudolarix]]'', ''[[Glyptostrobus]]'', ''[[Metasequoia]]'' and ''[[Taxodium]]'') are [[deciduous]], shedding their leaves in autumn.<ref name="Campbell-2005"/> The seedlings of some conifers, including pines, have a distinct juvenile foliage period where the leaves are different from the typical adult leaves.<ref name="RHS-Dict-1992">{{cite book |title=Royal Horticultural Society Dictionary of Gardening |publisher=[[Macmillan Press]]; Stockton Press |date=1992 |isbn=1-56159-001-0 |volume=3 |pages=582–594}}</ref> | ||
<gallery class=center mode=nolines widths=180 heights=180> | |||
File:20160118Pinus sylvestris1.jpg|[[Pinaceae]]: needle-like leaves of Scots pine (''[[Pinus sylvestris]]'') | |||
File:Araucaria Leaves.JPG|[[Araucariaceae]]: awl-like leaves of Cook pine (''[[Araucaria columnaris]]'') | |||
File:Abies grandis 5359.JPG|In ''[[Abies grandis]]'' and many other species with spirally arranged leaves, each leaf is twisted near its base to maximize light capture. | |||
File:C lawsoniana Lge.jpg|[[Cupressaceae]]: scale leaves of [[Chamaecyparis lawsoniana|Lawson's cypress]] (''Chamaecyparis lawsoniana''); scale in mm | |||
</gallery> | |||
=== Wood === | |||
Conifer [[xylem|wood]] consists of two types of [[cell (biology)|cells]]: [[parenchyma]], which have an oval or polyhedral shape, and strongly elongated [[tracheid]]s. Tracheids make up more than 90% of timber volume. The tracheids of earlywood formed at the beginning of a [[growing season]] have large radial sizes and smaller, thinner [[cell wall]]s. 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 ring]]s.<ref name="Ledig-1982">{{cite journal |last1=Ledig |first1=F. Thomas |last2=Porterfield |first2=Richard L. |date=1982 |title=Tree Improvement in Western Conifers: Economic Aspects |journal=[[Journal of Forestry]] |volume=80 |issue=10 |pages=653–657 |doi=10.1093/jof/80.10.653 |osti=5675533 }}</ref> | |||
[[ | |||
[[ | |||
[[ | |||
<gallery class=center mode=nolines widths=180 heights=180> | |||
File:Abies concolor tangential.jpg|Vertical (tangential) section of ''[[Abies concolor]]'' wood ([[xylem]]), showing [[tracheid]]s as long overlapping tubes. Perforation pits (small circles) allow water to move from one tracheid to the next. | |||
File:Report on the relation of railroads to forest supplies and forestry - together with appendices on the structure of some timber ties, their behavior, and the cause of their decay in the road bed, on (14755970324).jpg|Transverse section of wood, cutting across the [[tracheid]] tubes, showing [[tree ring]]s of fast (big cells, earlywood) and slow seasonal growth | |||
</gallery> | |||
=== Reproduction === | |||
===Reproduction=== | |||
{{Main|Conifer cone}} | {{Main|Conifer cone}} | ||
Most | Conifers produce their seeds inside a [[conifer cone|protective cone]] called a strobilus. Most species are [[Plant reproductive morphology#Terminology|monoecious]], with male and female cones on the same tree. All conifers are [[Anemophily|wind-pollinated]]. In conifers such as pines, the cones are [[wood]]y, and when mature the scales usually spread open allowing the seeds, which are often winged, to fall out and be dispersed by the [[wind]]. In others such as firs and cedars, the cones disintegrate to release the seeds.<ref name="Treeguide">{{cite web |title=Conifer Life Cycle |url=https://www.treeguideuk.co.uk/conifer-life-cycle/ |website=Tree Guide UK |access-date=20 September 2025}}</ref> | ||
Some conifers produce nut-like seeds, such as [[pine nut]]s, which are dispersed by [[bird]]s, in particular, [[Nutcracker (bird)|nutcracker]]s, and [[jay]]s, which break up the cones.<ref>{{cite book |last=Lanner |first=Ronald M. |title=Made for each other: A symbiosis of birds and pines |date=1996 |publisher=[[Oxford University Press]] |location=Oxford |isbn=0-19-508-903-0 |pages=61–75}}</ref><ref>{{cite book |last1=Tomback |first1=Diana F. |author-link=Diana Tomback |editor1-last=Sekercioglu |editor1-first=Cagan |editor2-last=Wenny |editor2-first=Daniel G. |editor3-last=Whelan |editor3-first=Christopher J. |title=Why birds matter: avian ecological function and ecosystem services |date=2016 |publisher=[[University of Chicago Press]] |location=Chicago |isbn=0-226-38263-X |page=201 |chapter=7}}</ref> | |||
In fire-adapted pines such as ''Pinus radiata'', the seeds may be stored in closed cones for many years, being released only when a [[Pyriscence|fire opens the cones]].<ref name="Rushforth-1987">{{cite book |last=Rushforth |first=Keith |title=Conifers |publisher=[[Christopher Helm Publishers]] |publication-place=London |date=1987-01-01 |isbn=0-7470-2801-X |pages=158–192}}</ref> | |||
In families such as [[Taxaceae]], the cone scales are much modified as edible [[aril]]s, resembling berries. These are eaten by fruit-eating birds, which then pass the seeds in their droppings.<ref>{{cite web |title=Tree ID: Yew tree |url=https://parks.wa.gov/about/news-center/field-guide-blog/tree-id-yew-tree |publisher=[[Washington State Parks]] |access-date=20 September 2025}}</ref> | |||
<gallery class=center mode=nolines widths=180 heights=180> | |||
<gallery class= | |||
File:Abies lasiocarpa 6972.JPG|Pinaceae: unopened female cones of [[Abies lasiocarpa|subalpine fir]] (''Abies lasiocarpa'') | File:Abies lasiocarpa 6972.JPG|Pinaceae: unopened female cones of [[Abies lasiocarpa|subalpine fir]] (''Abies lasiocarpa'') | ||
Taxus baccata MHNT.jpg|Taxaceae: the fleshy aril that surrounds each seed in the [[Taxus baccata|European yew]] | File:Spotted nutcracker with pine nut (cropped).jpg|[[Northern nutcracker]] with nut of ''[[Pinus sibirica]]'' | ||
Taxus baccata MHNT.jpg|Taxaceae: the fleshy [[aril]] that surrounds each seed in the [[Taxus baccata|European yew]] is a highly modified seed cone scale. | |||
Japanese Larch pollen cone, Cardiff, Wales.jpg|Pinaceae: pollen cone of a [[Japanese larch]] (''Larix kaempferi'') | Japanese Larch pollen cone, Cardiff, Wales.jpg|Pinaceae: pollen cone of a [[Japanese larch]] (''Larix kaempferi'') | ||
</gallery> | </gallery> | ||
===Life cycle=== | === Life cycle === | ||
[[File:Gymnosperm life cycle diagram-en.svg|thumb|upright=1.35|[[Biological life cycle|Life cycle]] of a pine tree]] | |||
Conifers are [[heterosporous]], generating two different types of spores: male [[microspore]]s and female [[megaspore]]s.<ref>{{cite book |last=Williams |first=Claire G. |title=Conifer Reproductive Biology |publisher=[[Springer Science+Business Media]] |publication-place=Dordrecht |year=2009 |isbn=978-1-4020-9601-3 |page=9}}</ref> These spores develop on separate male and female [[sporophylls]] on separate male and female cones, usually on the same tree.{{sfn|Williams|2009|pp=25–35}} | |||
In the male cones, microspores are produced from microsporocytes by [[meiosis]]. The microspores develop into pollen grains, which contain the male (micro)gametophytes. Large amounts of pollen are released and carried by the wind. Some pollen grains land on female cones, pollinating them. The generative cell in the pollen grain divides into two [[haploid]] sperm cells by [[mitosis]], leading to the development of the pollen tube. At fertilization, one of the sperm cells unites its haploid nucleus with the haploid nucleus of an egg cell.{{sfn|Williams|2009|pp=25–35}} | |||
The female cone develops two ovules, each of which contains haploid megaspores. A megasporocyte is divided by meiosis in each ovule. The female gametophytes grow to produce two or more haploid eggs. The fertilized egg, the ([[diploid]]) [[zygote]], gives rise to the [[embryo]], and a [[seed]] is produced. The female cone then opens, releasing the seeds which grow into [[seedling]]s. Some seedlings survive to grow into trees.{{sfn|Williams|2009|pp=25–35}} | |||
''' | Conifer reproduction is synchronous with seasonal changes in temperate zones. Reproductive development slows to a halt during each winter season and then resumes each spring. The male [[strobilus]] development is completed in a single year. Conifers have one of three reproductive cycles that differ in the time to complete female strobilus development from initiation to seed maturation. The cycle is one year in genera such as ''Abies'', ''Picea'', ''Cedrus'', and ''Tsuga''; two years in most pine species and in ''[[Sequoiadendron]]''; and three years in three pine species including ''[[Pinus pinea]]''. All three types have a long gap between [[pollination]] and [[fertilization]].{{sfn|Williams|2009|pp=101–102}} | ||
== Distribution and ecology == | |||
Conifers are the dominant plants over the [[taiga]] forest of the [[Northern Hemisphere]],<ref name="Campbell-2005"/> forming the world's largest terrestrial [[biome]]. The taiga consists mainly of larches, pines, and spruces.<ref name="Berkeley">{{cite web |url=http://www.ucmp.berkeley.edu/exhibits/biomes/forests.php#boreal |title=The forest biome |publisher=[[University of California Museum of Paleontology]] |location=Berkeley |access-date=12 May 2019 |archive-url=https://web.archive.org/web/20190620145416/https://ucmp.berkeley.edu/exhibits/biomes/forests.php#boreal |archive-date=20 June 2019 }}</ref> Larch is the most common tree in Russia, and by volume of timber, easily the most abundant tree genus worldwide.<ref name="Tsepliaev">{{cite book |last=Tsepliaev |first=Vasilii P. |date=1965 |title=The Forests of the U.S.S.R. |location=Jerusalem |publisher=Israel Program for Scientific Translations |page=289 (Table 86)}}</ref> The larch species ''[[Larix gmelinii]]'' is the world's most northerly-growing tree, at 75° north in the [[Taymyr Peninsula]].<ref name="Farjon 1999"/> Conifers are widespread also in southern Europe, the [[Middle East]], the [[Himalayas]], [[Southeast Asia]], and Japan. Conifers are not confined to the Northern Hemisphere: around 200 conifer species live only in the tropics, and others live in Australasia, Africa (including Madagascar), and Central and South America.<ref>{{cite web |title=Conifers of the World: Resources for Conifer Research |url=https://herbaria.plants.ox.ac.uk/bol/conifers |publisher=[[Oxford University Herbaria]] |access-date=20 September 2025}}</ref> Species richness decreases with latitude; a northern country like Canada has just 9 species, whereas Mexico has 43, and the tropical island of [[New Caledonia]] has 42 [[Endemism|endemic]] species.<ref name="Farjon 1999">{{cite journal |last=Farjon |first=Aljos |author-link=Aljos Farjon |title=Introduction to the Conifers |journal=[[Curtis's Botanical Magazine]] |volume=16 |issue=3 |year=1999 |pages=158–172 |jstor=45065379}}</ref> | |||
Since conifers cannot regrow their leaves rapidly like hardwoods, leaf<!--foliar--> diseases can seriously damage coniferous plantations, especially dense stands of young trees. [[Needle cast]] diseases, often caused by [[Ascomycota|ascomycete fungi]] in the [[Rhytismataceae]] family, result in leaf fall.<ref name="Worrall 2025">{{cite web |last=Worrall |first=J. |title=Foliage Diseases |url=https://forestpathology.org/foliage/ |website=Forest Pathology |access-date=20 September 2025}}</ref> Another ascomycete, ''Rhizosphaera'' ([[Sphaeropsidales]]), causes severe defoliation and shoot blight, for instance in spruces.<ref>{{cite web |title=Rhizosphaera Needle Cast |url=https://hort.extension.wisc.edu/articles/rhizosphaera-needle-cast/ |publisher=[[University of Wisconsin–Madison]]: Wisconsin Horticulture |access-date=7 September 2025}}</ref> | |||
At least 20 species of roundheaded wood-boring [[longhorn beetle]]s (Cerambycidae) feed on the wood of spruces, firs, and hemlocks.<ref name="Rose1985">Rose, A.H.; Lindquist, O.H. 1985. Insects of eastern spruces, fir and, hemlock, revised edition. Government of Canada, [[Canadian Forest Service]], Ottawa, Forestry Technical Report 23.</ref> [[Bark beetle]]s (Scolytinae, in the [[Curculionidae]]) are destructive pests of commercial forestry; major pests of spruce and other conifers include ''[[Ips typographus]]'' in Eurasia<ref name="Hlasny-2019">{{cite book |last=Hlasny |first=Tomas |display-authors=etal |title=Living with bark beetles: impacts, outlook and management options |date=2019 |publisher=[[European Forest Institute]] |isbn=978-952-5980-75-2 |pages=8-11 |url=https://efi.int/sites/default/files/files/publication-bank/2019/efi_fstp_8_2019_0.pdf}}</ref> and ''[[Dendroctonus rufipennis]]'' in North America.<ref>http://www.na.fs.fed.us/spfo/pubs/fidls/sprucebeetle/sprucebeetle.htm {{Webarchive|url=https://web.archive.org/web/20150217073724/http://www.na.fs.fed.us/spfo/pubs/fidls/sprucebeetle/sprucebeetle.htm |date=2015-02-17 }} USFS Spruce Beetle</ref> | |||
=== | The [[basidiomycete]] fungus ''[[Boletus pinophilus]]'' is among the fungi that form an [[ectomycorrhizal]] association with conifers, in its case with pines such as ''[[Pinus sylvestris]]''.<ref name="Gallardi-2020">{{cite book |last=Gallardi |first=Matteo |chapter=Diversity, Biogeographic Distribution, Ecology, and Ectomycorrhizal Relationships of the Edible Porcini Mushrooms (''Boletus'' s. str., Boletaceae) Worldwide: State of the Art and an Annotated Checklist |title=Mushrooms, Humans and Nature in a Changing World: Perspectives from Ecological, Agricultural and Social Sciences |editor=Pérez-Moreno, Jesús |editor2=Guerin-Laguette, Alexis |editor3=Arzú, Roberto Flores |editor4=Yu, Fu-Qiang |date=2020 |publisher=Springer |location=[[Cham, Switzerland]] |isbn=978-3-030-37378-8 |pages=236–237 |chapter-url=https://books.google.com/books?id=M3DgDwAAQBAJ&pg=PA237}}</ref> | ||
[[Wilding conifer|Some conifers introduced for forestry]] including ''[[Pinus radiata]]'' have become [[invasive species]] in New Zealand,<ref name="NZDeptConservation 2001">{{cite web |url=http://csl.doc.govt.nz/publications/conservation/threats-and-impacts/weeds/south-island-wilding-conifer-strategy/ |title=South Island wilding conifer strategy |publisher=[[Department of Conservation (New Zealand)]] |year=2001 |access-date=19 April 2009 |archive-date=14 August 2011 |archive-url=https://web.archive.org/web/20110814032140/http://csl.doc.govt.nz/publications/conservation/threats-and-impacts/weeds/south-island-wilding-conifer-strategy/ }}</ref> South Africa,<ref>{{cite conference |url=http://invasive.org/publications/xsymposium/proceed/13pg941.pdf |title=Biological Control of Alien, Invasive Pine Trees (Pinus species) in South Africa |journal=The X International Symposium on Biological Control of Weeds |date=4–14 July 1999 |location=Montana State University, Bozeman, Montana |editor-first=Neal R.|editor-last=Spencer |pages=941–953 |first1=V. C. |last1=Moran |first2=J. H. |last2=Hoffmann |first3=D. |last3=Donnelly |first4=B. W. |last4=van Wilgen |first5=H. G. |last5=Zimmermann |access-date=28 June 2016 |archive-date=6 October 2016 |archive-url=https://web.archive.org/web/20161006014151/http://www.invasive.org/publications/xsymposium/proceed/13pg941.pdf|url-status=live}}</ref> and Australia.<ref name="Lindemayer 2007">{{cite journal |last1=Lindenmayer |first1=D. B. |last2=Hobbs |first2=R. J. |title=Fauna conservation in Australian plantation forests – a review |journal=[[Biological Conservation (journal)|Biological Conservation]] |date=September 2004 |volume=119 |issue=2 |pages=151–168 |doi=10.1016/j.biocon.2003.10.028 |bibcode=2004BCons.119..151L }}</ref><ref>{{cite web |url=https://keyserver.lucidcentral.org/weeds/data/media/Html/pinus_radiata.htm |title=Pinus radiata |publisher=keyserver.lucidcentral.org |work=Weeds of Australia |date=2016 |access-date=22 August 2018 |archive-date=19 June 2017 |archive-url=https://web.archive.org/web/20170619101113/http://keyserver.lucidcentral.org/weeds/data/media/Html/pinus_radiata.htm |url-status=live}}</ref> | |||
== | <gallery class=center mode=nolines heights=180 widths=180> | ||
File:Siberian autumn in taiga..JPG|[[Taiga]] coniferous forest, mostly larches, pines, and spruces, covers a large area of [[Siberia]] (pictured) and Canada.<ref name="Berkeley"/> | |||
File:Kuuse-kooreürask ja tegutsemisjäljed Ips typographus.jpg|Galleries of ''[[Ips typographus]]'' bark beetles weaken conifers such as [[Picea abies|Norway spruce]], and can seriously harm commercial forestry. | |||
File:Boletus pinophilus3.JPG|The pine bolete ''[[Boletus pinophilus]]'' forms an [[ectomycorrhizal]] association with several pines. | |||
File:Prospect Pine Forest, Sydney.jpg|''[[Pinus radiata]]'' (radiata or Monterey pine) is an [[invasive species]] in Australia (pictured), New Zealand, and South Africa. | |||
</gallery> | |||
== Economic importance == | |||
{{further|Forestry|Silviculture}} | |||
=== | The [[softwood]] derived from conifers is more easily worked than [[hardwood]] from broadleaved ([[angiosperm]]) trees. This makes it widely used and of great economic value, its many uses including construction, furniture, telegraph poles and fencing.<ref name="Edlin 1966">{{cite book |last=Edlin |first=Herbert L. |author-link=Herbert L. Edlin |title=Know Your Conifers: Forestry Commission Booklet No. 15 |date=1966 |publisher=[[HMSO]] |pages=5–6 |url=https://cdn.forestresearch.gov.uk/1966/03/fcbk015.pdf}}</ref> A large part of [[Pulp and paper industry|production is used for paper]].<ref name="Edlin 1966"/><ref>{{cite book |last1=Mleziva |first1=M. M. |last2=Wang |first2=J. H. |chapter=Paper |title=Polymer Science: A Comprehensive Reference |date=2012 |pages=397–410 |isbn=978-0-08-087862-1 |doi=10.1016/B978-0-444-53349-4.00274-0}}</ref> In the United Kingdom, the 48% of the woodland that is coniferous yields over 90% of the timber; the top species is [[sitka spruce]], yielding about half of the timber produced.<ref name="Willoughby 2025">{{cite journal |last1=Willoughby |first1=Ian H. |last2=Dhanda |first2=Rajni |last3=Clarke |first3=Toni |last4=Reynolds |first4=Chris |title=Seventeen coniferous tree species show early promise for future commercial timber production in the UK |journal=[[Forestry journal|Forestry]]: An International Journal of Forest Research |date=10 August 2025 |doi=10.1093/forestry/cpaf048 |doi-access=free}}</ref> Worldwide, wood products reached a value of $100 billion by the end of the 20th century.<ref name="Farjon 1999"/> | ||
{{ | {{Annotated image 4 | ||
[[ | | header = Conifer [[wood]] | ||
| image = 4 conifer wood samples.jpg | |||
| align = center | |||
| image-width = 400 | |||
| width = 400 | |||
| height = 120 | |||
| annot-font-size = 12 | |||
| annot-color = f | |||
| annotations = | |||
{{Annotation| 35|90| [[Pine]] }} | |||
{{Annotation|125|90| [[Spruce]] }} | |||
{{Annotation|230|90| [[Larch]] }} | |||
{{Annotation|325|90| [[Juniper]] }} | |||
}} | |||
Conifers such as fir, cedar, cypress, juniper, spruce, pine, yew and [[Thuja|false cedar]] have been selected by plant breeders for ornamental purposes. Plants with unusual growth habits, sizes, and colours are propagated and planted in parks and gardens throughout the world.<ref name="Farjon-2010">{{cite book |last=Farjon |first=Aljos |author-link=Aljos Farjon |title=A Handbook of the World's Conifers |date=2010 |isbn=978-90-474-3062-9 |chapter=The economic importance of conifers |pages=25–29 |doi=10.1163/9789047430629}}</ref> | |||
<gallery class=center mode=nolines heights=180 widths=240> | |||
File:Young Sitka spruce plantation - geograph.org.uk - 949091.jpg|[[Forestry|Commercial forestry]] using [[sitka spruce]] | |||
File:2016.04.12 18.14.33 DSC03322 - Flickr - andrey zharkikh.jpg|''Globosa'', an ornamental [[cultivar]] of Scots pine | |||
File:JBP_Kotobuki.jpg|''[[Pinus thunbergii]]'' 'Kotobuki'<br/>as a 65-year-old [[bonsai]] | |||
</gallery> | |||
== References == | |||
{{reflist}} | |||
== External links == | |||
==External links== | |||
{{Commons category}} | {{Commons category}} | ||
{{Wikispecies|Pinophyta}} | {{Wikispecies|Pinophyta}} | ||
* [http://tolweb.org/tree?group=Conifers&contgroup=Spermatopsida Conifers] at the Tree of Life Web Project | * [http://tolweb.org/tree?group=Conifers&contgroup=Spermatopsida Conifers] at the Tree of Life Web Project | ||
* [ | * [https://s10.lite.msu.edu/res/msu/botonl/b_online/library/knee/hcs300/gymno.htm Gymnosperms] at Michigan State University | ||
* [https://herbaria.plants.ox.ac.uk/bol/conifers Conifers of the World: Resources for Conifer Research] - some 37,000 herbarium records | |||
* [https:// | |||
{{Pinophyta}} | {{Pinophyta}} | ||
{{Plant classification}} | {{Plant classification}} | ||
{{Life on Earth}} | {{Life on Earth}} | ||
{{Taxonbar|from=Q132825}} | {{Taxonbar|from=Q132825}} | ||
{{Authority control}} | {{Authority control}} | ||
Latest revision as of 21:26, 29 October 2025
Template:Short description Template:Good article Script error: No such module "other uses". Template:Use dmy dates Template:Use British English Template:Automatic taxobox
Conifers (Template:IPAc-en) are a group of seed plants, a subset of gymnosperms. They are mainly evergreen trees with a regular branching pattern, reproducing with male and female cones, usually on the same tree. They are wind-pollinated and the seeds are usually dispersed by the wind. Scientifically, they make up the division Pinophyta, also known as Coniferae. All extant conifers except for the Gnetophytes are perennial woody plants with secondary growth. There are over 600 living species.
Conifers first appear in the fossil record over 300 million years ago in the Carboniferous. They became dominant land plants in the Mesozoic, until flowering plants took over many ecosystems in the Cretaceous. Many conifers today are relict species, surviving in a small part of their former ranges. Such relicts include Wollemia, known only from a small area of Australia, and Metasequoia glyptostroboides, known from Cretaceous fossils and surviving in a small area of China.
Although the total number of species is relatively small, conifers are ecologically important. They are the dominant plants over the taiga of the Northern Hemisphere. Boreal conifers have multiple adaptations to survive winters, including a conical shape to shed snow, strong tracheid vessels to tolerate ice pressure, and a waxy covering on the needle leaves to minimise water loss. Several fungi form ectomycorrhizal associations with conifers. Other fungi cause diseases such as needle cast, especially harmful to young trees. Conifers are affected by pest insects such as wood-boring longhorn beetles and by bark beetles, which make galleries just under the bark. Conifers are of great economic value for timber and paper production.
Evolution
Fossil history
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 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.[1] Conifers were largely unaffected by the Permian–Triassic extinction event,[2] and were dominant land plants of the Mesozoic era. Modern groups of conifers emerged from the Voltziales during the Late Permian through Jurassic.[3] Conifers underwent a major decline in the Late Cretaceous corresponding to the explosive adaptive radiation of flowering plants.[4]
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Araucaria cone, Jurassic, Argentina
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Elatides foliage, Late Cretaceous, N. America
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Base of conifer trunk with roots, Early Miocene, Lesbos, Greece
Relict species
Several extant conifers have relict taxon status, surviving in small areas or in very small numbers where they once may have been common and widespread. One such is Wollemia nobilis, discovered in 1994 in some narrow, steep-sided, sandstone gorges in Australia.[5] The wild population consisted of under 60 adult trees with essentially no genetic variability, implying a genetic bottleneck some thousands of years ago.[6] The extant gnetophytes consist of three relict genera, namely Ephedra, Gnetum, and Welwitschia. Fossils definitely of the group date back to the Late Jurassic, with many species in the Cretaceous.[7] Conifers as a whole, too, declined markedly after the angiosperms (flowering plants) diversified during the Cretaceous, coming to dominate most terrestrial ecosystems. Many conifer species became extinct, leaving 30 out of 80 genera with just one extant species, and 11 more with just two or three species. The popular phrase "living fossils" could, the Dutch botanist Aljos Farjon states, fittingly be applied to many of these. Thus, Metasequoia glyptostroboides, the dawn redwood, is known from fossils of Late Cretaceous and Miocene age, and was found also as an extant tree with a small relict range in China.[8]
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Wollemia nobilis is a relict taxon known only from a small area in Australia.
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Welwitschia mirabilis is one of the gnetophytes, all relict taxa very unlike other conifers.
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Metasequoia glyptostroboides survives in a small part of China, and is known from fossils from the Late Cretaceous onwards.
External phylogeny
The cladogram summarizes the group's external phylogeny. The conifers are gymnosperms, sister to a clade consisting of the ginkgos and cycads.[9][10][11][12]
Internal phylogeny
The Gnetophyta, despite their distinct appearances, were long viewed as outside the conifer group, but phylogenomic analysis indicates that they are part of the conifer clade, sister to the pine family (the 'gnepine' hypothesis). If so, the gnetophytes once shared the distinctive characters of the conifers, and have lost them.[13] The cladogram summarizes the conifers' internal phylogeny:[14]
Taxonomy
The name conifer, meaning 'cone-bearing', derives from Latin Script error: No such module "Lang". (cone) and Script error: No such module "Lang". (to bear).[15] As recently as 1999, the botanist Aljos Farjon wrote that while the Coniferae had up to the early 20th century been considered "a natural family",[8] comparable to the Rosaceae, he doubted that the conifers or the gymnosperms formed natural groups (clades).[8] By 2016, the conifers were recognised as a clade, with six families (not including the gnetophytes),[16] 65–70 genera, and over 600 living species (Template:Circa).[17]Template:Rp[18][19] Depending on interpretation, the Cephalotaxaceae may or may not be included within the Taxaceae, while some authors recognize Phyllocladaceae as distinct from Podocarpaceae. The family Taxodiaceae is here included in the family Cupressaceae.[20]
Description
All living conifers (except the gnetophytes) are woody plants, and most are trees with narrow leaves, often needle-like. There are separate male and female reproductive structures, the cones. Pollination is always by wind; the seeds are mostly winged. The trees have a regular branching pattern. Many conifers have distinctly scented resin.[21] The world's tallest and oldest living trees are conifers. The tallest is a coast redwood (Sequoia sempervirens), with a height of Template:Convert.[22] Among the smallest conifers is the pygmy pine (Lepidothamnus laxifolius) of New Zealand, which is seldom taller than 30 cm when mature.[23] The oldest non-clonal living tree is a Great Basin bristlecone pine (Pinus longaeva), 4,700 years old.[24] Boreal conifers have multiple adaptations to survive winters, including the tree's conical shape to shed snow, strong tracheid vessels to tolerate ice pressure, and a waxy covering on the needle leaves to minimise water loss.[25]
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Oldest: Pinus longaeva can reach an age of 4,700 years.[24]
Foliage
Most conifers are evergreens.[26] In many species such as pines, firs, and cedars, the leaves are long, thin and needle-like. Others like cypresses have flat, triangular scale-like leaves.[27] 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 or 4. In many species with spirally arranged leaves, such as Abies grandis, 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 a maximum of energy from weak sunshine at high latitudes or under forest canopy shade. Conifers from lower latitudes 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 remain on 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.[26] The seedlings of some conifers, including pines, have a distinct juvenile foliage period where the leaves are different from the typical adult leaves.[28]
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Pinaceae: needle-like leaves of Scots pine (Pinus sylvestris)
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Araucariaceae: awl-like leaves of Cook pine (Araucaria columnaris)
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In Abies grandis and many other species with spirally arranged leaves, each leaf is twisted near its base to maximize light capture.
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Cupressaceae: scale leaves of Lawson's cypress (Chamaecyparis lawsoniana); scale in mm
Wood
Conifer wood consists of two types of cells: parenchyma, which have an oval or polyhedral shape, and strongly elongated tracheids. Tracheids make up more than 90% of timber volume. The tracheids of earlywood formed at 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.[29]
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Vertical (tangential) section of Abies concolor wood (xylem), showing tracheids as long overlapping tubes. Perforation pits (small circles) allow water to move from one tracheid to the next.
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Transverse section of wood, cutting across the tracheid tubes, showing tree rings of fast (big cells, earlywood) and slow seasonal growth
Reproduction
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Conifers produce their seeds inside a protective cone called a strobilus. Most species are monoecious, with male and female cones on the same tree. All conifers are wind-pollinated. In conifers such as pines, the cones are woody, and when mature the scales usually spread open allowing the seeds, which are often winged, to fall out and be dispersed by the wind. In others such as firs and cedars, the cones disintegrate to release the seeds.[30] Some conifers produce nut-like seeds, such as pine nuts, which are dispersed by birds, in particular, nutcrackers, and jays, which break up the cones.[31][32] In fire-adapted pines such as Pinus radiata, the seeds may be stored in closed cones for many years, being released only when a fire opens the cones.[33] In families such as Taxaceae, the cone scales are much modified as edible arils, resembling berries. These are eaten by fruit-eating birds, which then pass the seeds in their droppings.[34]
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Pinaceae: unopened female cones of subalpine fir (Abies lasiocarpa)
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Northern nutcracker with nut of Pinus sibirica
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Taxaceae: the fleshy aril that surrounds each seed in the European yew is a highly modified seed cone scale.
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Pinaceae: pollen cone of a Japanese larch (Larix kaempferi)
Life cycle
Conifers are heterosporous, generating two different types of spores: male microspores and female megaspores.[35] These spores develop on separate male and female sporophylls on separate male and female cones, usually on the same tree.Template:Sfn
In the male cones, microspores are produced from microsporocytes by meiosis. The microspores develop into pollen grains, which contain the male (micro)gametophytes. Large amounts of pollen are released and carried by the wind. Some pollen grains land on female cones, pollinating them. The generative cell in the pollen grain divides into two haploid sperm cells by mitosis, leading to the development of the pollen tube. At fertilization, one of the sperm cells unites its haploid nucleus with the haploid nucleus of an egg cell.Template:Sfn
The female cone develops two ovules, each of which contains haploid megaspores. A megasporocyte is divided by meiosis in each ovule. The female gametophytes grow to produce two or more haploid eggs. The fertilized egg, the (diploid) zygote, gives rise to the embryo, and a seed is produced. The female cone then opens, releasing the seeds which grow into seedlings. Some seedlings survive to grow into trees.Template:Sfn
Conifer reproduction is synchronous with seasonal changes in temperate zones. Reproductive development slows to a halt during each winter season and then resumes each spring. The male strobilus development is completed in a single year. Conifers have one of three reproductive cycles that differ in the time to complete female strobilus development from initiation to seed maturation. The cycle is one year in genera such as Abies, Picea, Cedrus, and Tsuga; two years in most pine species and in Sequoiadendron; and three years in three pine species including Pinus pinea. All three types have a long gap between pollination and fertilization.Template:Sfn
Distribution and ecology
Conifers are the dominant plants over the taiga forest of the Northern Hemisphere,[26] forming the world's largest terrestrial biome. The taiga consists mainly of larches, pines, and spruces.[36] Larch is the most common tree in Russia, and by volume of timber, easily the most abundant tree genus worldwide.[37] The larch species Larix gmelinii is the world's most northerly-growing tree, at 75° north in the Taymyr Peninsula.[8] Conifers are widespread also in southern Europe, the Middle East, the Himalayas, Southeast Asia, and Japan. Conifers are not confined to the Northern Hemisphere: around 200 conifer species live only in the tropics, and others live in Australasia, Africa (including Madagascar), and Central and South America.[38] Species richness decreases with latitude; a northern country like Canada has just 9 species, whereas Mexico has 43, and the tropical island of New Caledonia has 42 endemic species.[8]
Since conifers cannot regrow their leaves rapidly like hardwoods, leaf diseases can seriously damage coniferous plantations, especially dense stands of young trees. Needle cast diseases, often caused by ascomycete fungi in the Rhytismataceae family, result in leaf fall.[39] Another ascomycete, Rhizosphaera (Sphaeropsidales), causes severe defoliation and shoot blight, for instance in spruces.[40]
At least 20 species of roundheaded wood-boring longhorn beetles (Cerambycidae) feed on the wood of spruces, firs, and hemlocks.[41] Bark beetles (Scolytinae, in the Curculionidae) are destructive pests of commercial forestry; major pests of spruce and other conifers include Ips typographus in Eurasia[42] and Dendroctonus rufipennis in North America.[43]
The basidiomycete fungus Boletus pinophilus is among the fungi that form an ectomycorrhizal association with conifers, in its case with pines such as Pinus sylvestris.[44]
Some conifers introduced for forestry including Pinus radiata have become invasive species in New Zealand,[45] South Africa,[46] and Australia.[47][48]
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Galleries of Ips typographus bark beetles weaken conifers such as Norway spruce, and can seriously harm commercial forestry.
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The pine bolete Boletus pinophilus forms an ectomycorrhizal association with several pines.
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Pinus radiata (radiata or Monterey pine) is an invasive species in Australia (pictured), New Zealand, and South Africa.
Economic importance
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The softwood derived from conifers is more easily worked than hardwood from broadleaved (angiosperm) trees. This makes it widely used and of great economic value, its many uses including construction, furniture, telegraph poles and fencing.[49] A large part of production is used for paper.[49][50] In the United Kingdom, the 48% of the woodland that is coniferous yields over 90% of the timber; the top species is sitka spruce, yielding about half of the timber produced.[51] Worldwide, wood products reached a value of $100 billion by the end of the 20th century.[8] Template:Annotated image 4
Conifers such as fir, cedar, cypress, juniper, spruce, pine, yew and false cedar have been selected by plant breeders for ornamental purposes. Plants with unusual growth habits, sizes, and colours are propagated and planted in parks and gardens throughout the world.[52]
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Globosa, an ornamental cultivar of Scots pine
References
External links
- Conifers at the Tree of Life Web Project
- Gymnosperms at Michigan State University
- Conifers of the World: Resources for Conifer Research - some 37,000 herbarium records
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- ↑ Rose, A.H.; Lindquist, O.H. 1985. Insects of eastern spruces, fir and, hemlock, revised edition. Government of Canada, Canadian Forest Service, Ottawa, Forestry Technical Report 23.
- ↑ Script error: No such module "citation/CS1".
- ↑ http://www.na.fs.fed.us/spfo/pubs/fidls/sprucebeetle/sprucebeetle.htm Template:Webarchive USFS Spruce Beetle
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