Editing Invasive species (section)

=== Taxon substitution ===
[[File:Aldabra Giant Tortoise, Ile aux Aigrettes Nature Reserve, Mauritius.JPG|thumb|The [[Aldabra giant tortoise]] has helped to restore ecological equilibrium on two islets off Mauritius, including the [[Île aux Aigrettes]] (pictured). ]]

Non-native species can be introduced to fill an ecological engineering role that previously was performed by a native species now extinct. The procedure is known as taxon substitution.<ref name=potential/><ref>{{cite web |url=https://www.sciencedaily.com/releases/2011/02/110211095555.htm |title=Invasive plants can create positive ecological change |work=Science Daily |date=February 14, 2011 |quote="Invasive species could fill niches in degraded ecosystems and help restore native biodiversity...." |access-date=June 22, 2017 |archive-date=May 25, 2017 |archive-url=https://web.archive.org/web/20170525102601/https://www.sciencedaily.com/releases/2011/02/110211095555.htm |url-status=live}}</ref><ref>{{cite journal |last1=Searcy |first1=Christopher A. |last2=Rollins |first2=Hilary B. |last3=Shaffer |first3=H. Bradley |title=Ecological equivalency as a tool for endangered species management |year=2016 |journal=[[Ecological Applications]] |volume=26 |issue=1 |pages=94–103 |pmid=27039512 |doi=10.1890/14-1674 |doi-access=free|bibcode=2016EcoAp..26...94S }}</ref> On many islands, tortoise extinction has resulted in dysfunctional ecosystems with respect to seed dispersal and herbivory. On the offshore islets of [[Mauritius]], tortoises now extinct had served as the keystone herbivores. Introduction of the non-native [[Aldabra giant tortoise]]s on two islets in 2000 and 2007 has begun to restore ecological equilibrium. The introduced tortoises are dispersing seeds of several native plants and are selectively grazing invasive plant species. Grazing and browsing are expected to replace ongoing intensive manual weeding, and the introduced tortoises are already breeding.<ref>{{cite journal |last1=Hansen |first1=Dennis M. |last2=Donlan |first2=C. Josh |last3=Griffiths |first3=Christine J. |last4=Campbell |first4=Karl J. |title=Ecological history and latent conservation potential: Large and giant tortoises as a model for taxon substitutions |year=2010 |journal=[[Ecography]] |volume=33 |issue=2 |pages=272–284 |doi=10.1111/j.1600-0587.2010.06305.x |doi-access=free|bibcode=2010Ecogr..33..272H }}</ref>