Editing Eucalyptus (section)

==Non-native ''Eucalyptus'' and biodiversity==
Due to similar favourable climatic conditions, ''Eucalyptus'' plantations have often replaced [[oak]] woodlands, for example in California, Spain and Portugal. The resulting monocultures have raised concerns about loss of biological diversity, through loss of [[acorn]]s that [[mammal]]s and birds feed on, absence of hollows that in oak trees provide shelter and nesting sites for birds and small mammals and for bee colonies, as well as lack of downed trees in managed plantations. A study of the relationship between birds and ''Eucalyptus'' in the San Francisco Bay Area found that bird diversity was similar in native forest versus ''Eucalyptus'' forest, but the species were different.<ref>{{cite journal |title=Equal diversity in disparate species assemblages: a comparison of native and exotic woodlands in California |author=Sax, Dov F. |year=2002 |journal=Global Ecology and Biogeography |pages=49–57 |doi=10.1046/j.1466-822X.2001.00262.x |volume=11 |issue=1 |bibcode=2002GloEB..11...49S |doi-access=free }}</ref> One way in which the avifauna (local assortment of bird species) changes is that cavity-nesting birds including woodpeckers, owls, chickadees, wood ducks, etc. are [[depauperate]] in ''Eucalyptus'' groves because the decay-resistant wood of these trees prevents cavity formation by decay or excavation. Also, those bird species that glean insects from foliage, such as warblers and vireos, experience population declines when ''Eucalyptus'' groves replace oak forest.{{cn|date=June 2024}}

Birds that thrive in ''Eucalyptus'' groves in California tend to prefer tall vertical habitat. These avian species include herons and egrets, which also nest in redwoods.<ref>{{cite report |title=Birds and Eucalyptus on the Central California Coast: A Love-Hate Relationship |author=David L. Suddjian |publisher=David Suddian Biological Consulting |date=2004-06-03 |url=http://www.elkhornsloughctp.org/uploads/1108147180Suddjian-unpublished%20conference%20notes.pdf |access-date=2013-11-22 |archive-url=https://web.archive.org/web/20120326062119/http://www.elkhornsloughctp.org/uploads/1108147180Suddjian-unpublished%20conference%20notes.pdf |archive-date=2012-03-26 |url-status=dead}}</ref><ref name="Kelly1993">{{cite journal|last1=Kelly|first1=J.P.|last2=Pratt|first2=H.M.|last3=Greene|first3=P.L.|title=The Distribution, Reproductive Success, and Habitat Characteristics of Heron and Egret Breeding Colonies in the San Francisco Bay Area|journal=Colonial Waterbirds |volume=16|issue=1|year=1993|pages=18–27|doi=10.2307/1521552 |jstor=1521552}}</ref> The [[Point Reyes Bird Observatory]] observes that sometimes short-billed birds like the [[ruby-crowned kinglet]] are found dead beneath ''Eucalyptus'' trees with their nostrils clogged with pitch.<ref name="NPS" />

[[Monarch (butterfly)|Monarch]] butterflies use ''Eucalyptus'' in California for overwintering, but in some locations have a preference for [[Monterey pine]]s.<ref name="NPS" />

=== ''Eucalyptus'' as an invasive species ===
''Eucalyptus'' trees are considered invasive to local ecosystems and negatively impact water resources in countries where they are introduced.<ref name="invasive" />

'''South Africa'''

In South Africa, ''Eucalyptus'' tree species ''E. camaldulensis'', ''E. cladocalyx'', ''E.'' ''conferruminata,'' ''E. diversicolor'', ''E. grandis'' and ''E. tereticornis'' are listed as Category 1b invaders in the [[National Environmental Management Act, 1998|National Environmental Management]]: Biodiversity Act. This means most activities with regards to the species are prohibited (such as importing, propagating, translocating or trading) and it should be ensured that it does not spread beyond a plantation's domain.<ref>{{Cite journal |title=South African Government Gazette: Number 37320 |url=https://archive.gazettes.africa/archive/za/2014/za-government-gazette-dated-2014-02-12-no-37320.pdf |journal=[[Government Gazette of South Africa]] |volume=584 |pages=28}}</ref>

''E. cladocalyx'' and ''E. diversicolor'' are considered [[Fynbos]] invaders,<ref>{{Citation |last1=Le Maitre |first1=David C. |title=Impacts of Plant Invasions on Terrestrial Water Flows in South Africa |date=2020 |work=Biological Invasions in South Africa |pages=431–457 |editor-last=van Wilgen |editor-first=Brian W. |series=Invading Nature - Springer Series in Invasion Ecology |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-030-32394-3_15 |isbn=978-3-030-32394-3 |last2=Blignaut |first2=James N. |last3=Clulow |first3=Alistair |last4=Dzikiti |first4=Sebinasi |last5=Everson |first5=Colin S. |last6=Görgens |first6=André H. M. |last7=Gush |first7=Mark B. |s2cid=216398000 |editor2-last=Measey |editor2-first=John |editor3-last=Richardson |editor3-first=David M. |editor4-last=Wilson |editor4-first=John R.|doi-access=free }}</ref> and use up to 20% more water than the native fynbos vegetation; with invasive species including ''Eucalyptus'' being cleared that reduce Cape Town's water resource by 55 billion litres or two months worth of water supply.<ref>{{Cite web|url=https://www.nature.org/content/dam/tnc/nature/en/documents/GCTWF-Business-Case_2018-11-14_Web.pdf|title=THE GREATER CAPE TOWN WATER FUND - ASSESSING THE RETURN ON INVESTMENT FOR ECOLOGICAL INFRASTRUCTURE RESTORATION}}</ref><ref>{{Cite web |last=Coles |first=Wayne |date=2020-01-21 |title=Eucalyptus - the 'thirsty' trees threatening to 'drink' South Africa dry |url=https://blog.invasive-species.org/2020/01/21/eucalyptus-the-thirsty-trees-threatening-to-drink-south-africa-dry/ |access-date=2023-09-09 |website=Invasive Species Blog |language=en-GB}}</ref>