Editing Permian–Triassic extinction event (section)

=== Terrestrial plants ===
The [[Geologic record|geological record]] of [[terrestrial plant|terrestrial]] plants is sparse and based mostly on [[pollen]] and [[spore]] studies. Floral changes across the Permian-Triassic boundary are highly variable depending on the location and preservation quality of any given site.<ref>{{cite journal |last1=Rees |first1=P. McAllister |date=1 September 2002 |title=Land-plant diversity and the end-Permian mass extinction |url=https://pubs.geoscienceworld.org/gsa/geology/article-abstract/30/9/827/192461/Land-plant-diversity-and-the-end-Permian-mass |journal=[[Geology (journal)|Geology]] |volume=30 |issue=9 |pages=827–830 |doi=10.1130/0091-7613(2002)030<0827:LPDATE>2.0.CO;2 |bibcode=2002Geo....30..827M |access-date=31 May 2023|url-access=subscription }}</ref> Plants are relatively immune to mass extinction, with the impact of all the major mass extinctions "insignificant" at a family level.<ref name=McElwain2007 />{{Dubious|date=May 2020}} Floral diversity losses were more superficial than those of marine animals.<ref>{{Cite journal |last=Ponomarenko |first=A. G. |date=August 2006 |title=Changes in terrestrial biota before the Permian-Triassic ecological crisis |url=https://link.springer.com/article/10.1134/S0031030106100066 |journal=[[Paleontological Journal]] |language=en |volume=40 |issue=4 |pages=S468–S474 |doi=10.1134/S0031030106100066 |bibcode=2006PalJ...40S.468P |issn=0031-0301 |access-date=13 October 2024 |via=Springer Link|url-access=subscription }}</ref> Even the reduction observed in species diversity (of 50%) may be mostly due to [[Taphonomy|taphonomic]] processes.<ref name=":0">{{cite journal |last1=Nowak |first1=Hendrik |last2=Schneebeli-Hermann |first2=Elke |last3=Kustatscher |first3=Evelyn |date=23 January 2019 |title=No mass extinction for land plants at the Permian–Triassic transition |journal=[[Nature Communications]] |volume=10 |issue=1 |page=384 |doi=10.1038/s41467-018-07945-w |pmid=30674875 |pmc=6344494 |bibcode=2019NatCo..10..384N }}</ref><ref name="McElwain2007" /> However, a massive rearrangement of ecosystems does occur, with plant abundances and distributions changing profoundly and all the forests virtually disappearing.<ref>{{cite web|url=http://www.nhm.ac.uk/nature-online/life/dinosaurs-other-extinct-creatures/mass-extinctions/end-permian-mass-extinction/index.html|title=The Dino Directory – Natural History Museum}}</ref><ref name="McElwain2007" /> The dominant floral groups changed, with many groups of land plants entering abrupt decline, such as ''[[Cordaites]]'' ([[gymnosperm]]s) and ''[[Glossopteris]]'' ([[Pteridospermatophyta|seed ferns]]).<ref name="GulbransonEtAl2022">{{cite journal |last1=Gulbranson |first1=Erik L. |last2=Mellum |first2=Morgan M. |last3=Corti |first3=Valentina |last4=Dahlseid |first4=Aidan |last5=Atkinson |first5=Brian A. |last6=Ryberg |first6=Patricia E. |last7=Cornamusini |first7=Giancula |date=24 May 2022 |title=Paleoclimate-induced stress on polar forested ecosystems prior to the Permian–Triassic mass extinction |journal=Scientific Reports |volume=12 |issue=1 |page=8702 |bibcode=2022NatSR..12.8702G |doi=10.1038/s41598-022-12842-w |pmc=9130125 |pmid=35610472}}</ref><ref name="Retallack1995">{{cite journal |last=Retallack |first=G. J. |year=1995 |title=Permian–Triassic life crisis on land |journal=[[Science (journal)|Science]] |volume=267 |issue=5194 |pages=77–80 |bibcode=1995Sci...267...77R |doi=10.1126/science.267.5194.77 |pmid=17840061 |s2cid=42308183}}</ref> The severity of plant extinction has been disputed.<ref name="Cascales-Miñana2011">{{Cite journal | last1 = Cascales-Miñana | first1 = B. | last2 = Cleal | first2 = C. J. | title = Plant fossil record and survival analyses | journal = [[Lethaia]] | pages = 71–82 | year = 2011 | doi = 10.1111/j.1502-3931.2011.00262.x | volume=45}}</ref><ref name=":0" />

The ''Glossopteris''-dominated flora that characterized high-latitude Gondwana collapsed in Australia around 370,000 years before the Permian-Triassic boundary, with this flora's collapse being less constrained in western Gondwana but still likely occurring a few hundred thousand years before the boundary.<ref name="JosefinaBodnar" /> The collapse of this flora is indirectly marked by an abrupt change in river morphology from meandering to braided river systems, signifying the widespread demise of rooted plants.<ref>{{Cite journal |last1=Ward |first1=Peter Douglas |last2=Montgomery |first2=David R. |last3=Smith |first3=Roger |date=8 September 2000 |title=Altered River Morphology in South Africa Related to the Permian-Triassic Extinction |url=https://www.science.org/doi/10.1126/science.289.5485.1740 |journal=[[Science (journal)|Science]] |language=en |volume=289 |issue=5485 |pages=1740–1743 |doi=10.1126/science.289.5485.1740 |pmid=10976065 |bibcode=2000Sci...289.1740W |issn=0036-8075 |access-date=13 October 2024|url-access=subscription }}</ref>

[[Palynological]] or pollen studies from East [[Greenland]] of sedimentary rock strata laid down during the extinction period indicate dense gymnosperm [[woodland]]s before the event. At the same time that marine [[invertebrate]] macrofauna declined, these large woodlands died out and were followed by a rise in diversity of smaller [[herbaceous]] plants including [[Lycopodiophyta]], both [[Selaginellales]] and [[Isoetales]].<ref name="LooyEtAl2005EndPermianDeadZone" /> Data from Kap Stosch suggest that floral species richness was not significantly affected during the PTME.<ref>{{Cite journal |last1=Schneebeli-Hermann |first1=Elke |last2=Hochuli |first2=Peter A. |last3=Bucher |first3=Hugo |date=August 2017 |title=Palynofloral associations before and after the Permian–Triassic mass extinction, Kap Stosch, East Greenland |url=https://linkinghub.elsevier.com/retrieve/pii/S0921818117301303 |journal=[[Global and Planetary Change]] |language=en |volume=155 |pages=178–195 |doi=10.1016/j.gloplacha.2017.06.009 |bibcode=2017GPC...155..178S |access-date=11 September 2024 |via=Elsevier Science Direct|url-access=subscription }}</ref>

The ''Cordaites'' flora, which dominated the Angaran floristic realm corresponding to Siberia, collapsed over the course of the extinction.<ref name="VajdaMcLoughlin2007" /> In the [[Kuznetsk Basin]], the aridity-induced extinction of the regional humid-adapted forest flora dominated by cordaitaleans occurred approximately 252.76 Ma, around 820,000 years before the end-Permian extinction in South China, suggesting that the end-Permian biotic catastrophe may have started earlier on land and that the ecological crisis may have been more gradual and asynchronous on land compared to its more abrupt onset in the marine realm.<ref name="DavydovEtAl2021PPP">{{cite journal |last1=Davydov |first1=V. I. |last2=Karasev |first2=E. V. |last3=Nurgalieva |first3=N. G. |last4=Schmitz |first4=M. D. |last5=Budnikov |first5=I. V. |last6=Biakov |first6=A. S. |last7=Kuzina |first7=D. M. |last8=Silantiev |first8=V. V. |last9=Urazaeva |first9=M. N. |last10=Zharinova |first10=V. V. |last11=Zorina |first11=S. O. |last12=Gareev |first12=B. |last13=Vasilenko |first13=D. V. |date=1 July 2021 |title=Climate and biotic evolution during the Permian-Triassic transition in the temperate Northern Hemisphere, Kuznetsk Basin, Siberia, Russia |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018221002170 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=573 |page=110432 |doi=10.1016/j.palaeo.2021.110432 |bibcode=2021PPP...57310432D |s2cid=235530804 |access-date=19 December 2022|url-access=subscription }}</ref>

In North China, the transition between the Upper Shihhotse and Sunjiagou Formations and their lateral equivalents marked a very large extinction of plants in the region. Those plant genera that did not go extinct still experienced a great reduction in their geographic range. Following this transition, coal swamps vanished. The North Chinese floral extinction correlates with the decline of the ''Gigantopteris'' flora of South China.<ref>{{cite journal |last1=Xiong |first1=Conghui |last2=Wang |first2=Jiashu |last3=Huang |first3=Pu |last4=Cascales-Miñana |first4=Borja |last5=Cleal |first5=Christopher J. |last6=Benton |first6=Michael James |last7=Xue |first7=Jinzhuang |date=December 2021 |title=Plant resilience and extinctions through the Permian to Middle Triassic on the North China Block: A multilevel diversity analysis of macrofossil records |url=https://www.sciencedirect.com/science/article/abs/pii/S0012825221003470 |journal=[[Earth-Science Reviews]] |volume=223 |page=103846 |doi=10.1016/j.earscirev.2021.103846 |bibcode=2021ESRv..22303846X |s2cid=240118558 |access-date=28 March 2023|hdl=20.500.12210/76649 |hdl-access=free }}</ref>

In South China, the subtropical [[Cathaysia]]n [[gigantopterid]] dominated rainforests abruptly collapsed.<ref>{{cite journal |last1=Zhang |first1=Hua |last2=Cao |first2=Chang-qun |last3=Liu |first3=Xiao-lei |last4=Mu |first4=Lin |last5=Zheng |first5=Quan-feng |last6=Liu |first6=Feng |last7=Xiang |first7=Lei |last8=Liu |first8=Lu-jun |last9=Shen |first9=Shu-zhong |date=15 April 2016 |title=The terrestrial end-Permian mass extinction in South China |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018215003624 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=448 |pages=108–124 |doi=10.1016/j.palaeo.2015.07.002 |bibcode=2016PPP...448..108Z |access-date=20 January 2023|url-access=subscription }}</ref><ref>{{cite journal |last1=Chu |first1=Daoliang |last2=Yu |first2=Jianxin |last3=Tong |first3=Jinnan |last4=Benton |first4=Michael James |last5=Song |first5=Haijun |last6=Huang |first6=Yunfei |last7=Song |first7=Ting |last8=Tian |first8=Li |date=November 2016 |title=Biostratigraphic correlation and mass extinction during the Permian-Triassic transition in terrestrial-marine siliciclastic settings of South China |url=https://www.sciencedirect.com/science/article/abs/pii/S0921818116300182#! |journal=[[Global and Planetary Change]] |volume=146 |pages=67–88 |doi=10.1016/j.gloplacha.2016.09.009 |bibcode=2016GPC...146...67C |hdl=1983/2d475883-42ea-4988-b01c-0a56912e6aec |access-date=12 November 2022|hdl-access=free }}</ref><ref name="FengEtAl2020EarthScience" /> The floral extinction in South China is associated with bacterial blooms in soil and nearby lacustrine ecosystems, with soil erosion resulting from the die-off of plants being their likely cause.<ref>{{cite journal |last1=Biswas |first1=Raman Kumar |last2=Kaiho |first2=Kunio |last3=Saito |first3=Ryosuke |last4=Tian |first4=Li |last5=Shi |first5=Zhiqiang |date=December 2020 |title=Terrestrial ecosystem collapse and soil erosion before the end-Permian marine extinction: Organic geochemical evidence from marine and non-marine records |url=https://www.sciencedirect.com/science/article/abs/pii/S0921818120302186 |journal=[[Global and Planetary Change]] |volume=195 |page=103327 |doi=10.1016/j.gloplacha.2020.103327 |bibcode=2020GPC...19503327B |s2cid=224900905 |access-date=21 December 2022|url-access=subscription }}</ref> Wildfires too likely played a role in the fall of ''Gigantopteris''.<ref name="EcologicalDisturbanceTropicalPeatlands" />

A conifer flora in what is now Jordan, known from fossils near the [[Dead Sea]], showed unusual stability over the Permian-Triassic transition, and appears to have been only minimally affected by the crisis.<ref>{{cite journal |last1=Blomenkemper |first1=Patrick |last2=Kerp |first2=Hans |last3=Abu Hamad |first3=Abdalla |last4=DiMichele |first4=William A. |last5=Bomfleur |first5=Benjamin |date=21 December 2018 |title=A hidden cradle of plant evolution in Permian tropical lowlands |journal=[[Science (journal)|Science]] |volume=362 |issue=6421 |pages=1414–1416 |doi=10.1126/science.aau4061 |pmid=30573628 |bibcode=2018Sci...362.1414B |s2cid=56582195 |doi-access=free }}</ref>