Editing Fraxinus excelsior (section)

==Ecology==
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| image2 = Ash (Fraxinus excelsior) Wales 190310 (Tony Holkham).jpg
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| footer = Ash tree (~20m tall) in [[Wales]] at 185 m asl in July (l) and March (r), showing branch structure
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Ash occurs on a wide range of [[soil]] types, but is particularly associated with basic soils on calcareous substrates. The most northerly ashwood in Britain is on limestone at Rassal, [[Wester Ross]], latitude 57.4278 N.<ref name="SNH">{{cite web |title=Wood Pasture: Rassal Ashwood National Nature Reserve |url=http://www.snh.org.uk/publications/on-line/heritagemanagement/woodpasture/RassalAshwood.asp |publisher=Scottish Natural Heritage|archiveurl=https://web.archive.org/web/20130906153044/http://www.snh.org.uk/publications/on-line/heritagemanagement/woodpasture/RassalAshwood.asp|archive-date=2013-09-06 }}</ref> Ash prefers moister soil types and is commonly limited by temperature and so not found at the higher colder altitudes in much of Europe, though in Iran, it may reach 2000 m asl. As a young seedling, it is shade tolerant, but older trees are light-demanding. It is an early-[[Ecological succession|succession]] species and may well outcompete beech and oak, which are later-succession species.<ref>{{cite journal |title=A review of European ash (''Fraxinus excelsior'' L.): implications for silviculture Forestry |author1=Dorota Dobrowolska |author2=Sebastian Hein |author3=Anne Oosterbaan |author4=Sven Wagner |author5=Jo Clark |author6=Jens Peter Skovsgaard |date=April 2011 |journal=Forestry: An International Journal of Forest Research |volume=84 |issue=2 |pages=133–148 |doi=10.1093/forestry/cpr001 |doi-access=free}}</ref>

''F. excelsior'' mycorrhizae are of the internal [[arbuscular mycorrhiza]]l type, in which the fungus grows within the tissues of the root and forms branched, tree-like structures within the cells of the root cortex. Unlike other ''Fraxinus'' species, ''F. excelsior'' does not form [[ectomycorrhiza]]e.<ref name="Thomas-2016"/>

The [[Biological Records Centre]] of the UK records 111 species of insects and mites using ash as a food plant, of which 29 are specific to ash. A further six are specific to ash and its [[Oleaceae]] relative wild privet (''[[Ligustrum vulgare]]'').<ref name="Rackham-2014">{{cite book|last1=Rackham|first1=Oliver|author-link1=Oliver Rackham|title=The Ash Tree|date=2014|publisher=Little Toller Books|location=Toller Fratrum, Dorset|isbn=978-1-908213-14-3 |pages=25–6}}</ref> A number of [[Lepidoptera]] species use the species as a food source.<ref>{{cite web |title=Invertebrates associated with Ash |url=http://www.buglife.org.uk/Resources/Buglife/Invertebrates%20associated%20with%20Ash%20.pdf |access-date=2015-02-28 |author=Alan Stubbs |url-status=dead |archive-url=https://web.archive.org/web/20130903163200/http://www.buglife.org.uk/Resources/Buglife/Invertebrates%20associated%20with%20Ash%20.pdf |archive-date=3 September 2013}}</ref> One example of an ash-specific feeding moth is the centre-barred sallow (''[[Atethmia centrago]]''). The larvae burrow into the buds when newly hatched and later feed on the flowers and leaves.<ref>{{cite web|title=Centre-barred Sallow Atethmia centrago |url=http://www.ukmoths.org.uk/species/atethmia-centrago|website=UKmoths|access-date=28 July 2017}}</ref> A common moth which causes the browning of ash leaves, as well as [[garden privet]] and [[lilac]], is ''[[Gracillaria syringella]]''. The usually gregarious larvae form an epidermal gallery (i.e. feed within the leaf) which leads to a [[Leaf miner|brown blotch]] with black [[frass]]. Later, two successive cones are formed by folding the tip of a leaf downwards.<ref>{{cite web|title=15.014 Gracillaria syringella (Fabricius, 1794)|url=http://www.leafmines.co.uk/html/Lepidoptera/C.syringella.htm|website=British leafminers|access-date=28 July 2017}}</ref>

In Britain, 14 [[galls]] have been recorded on ash. The [[British Plant Gall Society]] defines a gall as "... an abnormal growth produced by a plant under the influence of another organism".<ref name="Redfern-2011">{{cite book|last1=Redfern|first1=Margaret|last2=Shirley|first2=Peter|last3=Bloxham|first3=Michael|title=British Plant Galls|date=2011|publisher=FSC Publications|location=Shrewsbury|isbn=978-1-85153-284-1|edition=Second}}</ref>
<!-- The following galls are formed on ash. 
* ''[[Nectria galligena]]'' 
* ''[[Meloidogyne ardenensis]]''
* ''[[Aceria fraxinivora]]''
* ''[[Contarinia marchali]]''
* ''[[Prociphilus fraxini]]''
* ''[[Prociphilus bumeliae]]''
* ''[[Dasineura acrophila]]''
* ''[[Dasineura fraxini]]''
* ''[[Aculus fraxini]]''
* ''[[Psyllopsis fraxini]]''
* ''[[Psyllopsos fraxinicola]]''
* ''[[Dasineura fraxinea]]''
* ''[[Aceria fraxinicilla]]''
* ''[[Aculus epiphyllus]]''
-->

===Ash dieback===
Ash dieback is caused by the [[fungus]] ''[[Hymenoscyphus fraxineus]]'' which was previously known as ''[[Chalara fraxinea]].''
Research into the genetics of the resistance of ash (''Fraxinus excelsior'') has shown that resistance does occur in European populations, but at least for the samples tested, it is neither common nor strong.<ref>{{cite journal |title=Clonal differences in susceptibility to the dieback of ''Fraxinus excelsior'' in southern Sweden |vauthors=Stener LG |year=2012 |journal=Scandinavian Journal of Forest Research |doi=10.1080/02827581.2012.735699 |volume=28 |issue = 3|pages=205–216|s2cid=85292870 }}</ref><ref>{{cite journal |title=Adaptive potential of ash (''Fraxinus excelsior'') populations against the novel emerging pathogen ''Hymenoscyphus pseudoalbidus''|vauthors=Kjær ED |year=2012 |journal=Evolutionary Applications |display-authors=etal |doi=10.1111/j.1752-4571.2011.00222.x |pmid=25568043 |pmc=3353348 |volume=5 |issue = 3|pages=219–228|bibcode=2012EvApp...5..219K }}</ref><ref>{{cite journal |title=Presence of natural genetic resistance in ''Fraxinus excelsior'' (Oleraceae) to ''Chalara fraxinea'' (Ascomycota): an emerging infectious disease|vauthors=McKinney LV |year=2011 |journal=Heredity|display-authors=etal |volume=106 |issue=5|doi=10.1038/hdy.2010.119 |pmid=20823903|pages=788–797|pmc=3186218|bibcode=2011Hered.106..788M }}</ref><ref name="Pliūra-2011">{{cite journal |vauthors=Pliūra A, Lygis V, Suchockas V, Bartkevičius E |year=2011 |title=Performance of twenty four European ''Fraxinus excelsior'' populations in three Lithuanian progeny trials with a special emphasis on resistance to ''Chlara fraxinea'' |journal=Baltic Forestry |volume=17 |issue=1 |pages=17–34 |url=http://www.balticforestry.mi.lt/bf/index.php?option=com_content&view=article&id=267:pliura-a-lygis-v-suchockas-v-and-bartkevicius-e-2011-performance-of-twenty-four-european-fraxinus-excelsior-populations-in-three-lithuanian-progeny-trials-with-a-special-emphasis-on-resistance-to-chlara-fraxinea-baltic-forestry-17-1-17-34&catid=33:baltic-forestry-2011-17-1 |archiveurl=https://web.archive.org/web/20150402142745/http://www.balticforestry.mi.lt/bf/index.php?option=com_content&view=article&id=267:pliura-a-lygis-v-suchockas-v-and-bartkevicius-e-2011-performance-of-twenty-four-european-fraxinus-excelsior-populations-in-three-lithuanian-progeny-trials-with-a-special-emphasis-on-resistance-to-chlara-fraxinea-baltic-forestry-17-1-17-34&catid=33:baltic-forestry-2011-17-1|archive-date=2015-04-02 }}</ref> Due to the importance of ''F. excelsior'' as a host, Jönsson and Thor 2012 find that rare/threatened [[lichen]]s face an unusually high (0.38) [[coextinction risk probability]] ''vis-a-vis'' the host tree in the [[wooded meadow]]s of [[Gotland]], Sweden.<ref name="Oliva-2020">{{cite journal | last1=Oliva | first1=Jonàs | last2=Redondo | first2=Miguel Ángel | last3=Stenlid | first3=Jan | title=Functional Ecology of Forest Disease | journal=[[Annual Review of Phytopathology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=58 | issue=1 | date=2020-08-25 | issn=0066-4286 | doi=10.1146/annurev-phyto-080417-050028 | pages=343–361| pmid=32396761 | bibcode=2020AnRvP..58..343O | s2cid=218618105 }}</ref>