Quercus tomentella
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Quercus tomentella, the island oak,<ref name=jeps>Template:Jepson eFlora</ref> island live oak,<ref name=usda>Template:PLANTS</ref> or Channel Island oak,<ref name=fna>Template:EFloras</ref> is an oak in the section Protobalanus. It is native to six islands: five of the Channel Islands of California and Guadalupe Island, part of Baja California.
It is placed in Quercus section Protobalanus.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
DescriptionEdit
Island oak is a tree growing up to Template:Convert in height.<ref name=fna/> The mature tree has a grayish to reddish brown trunk with scaly, furrowed bark.<ref name=jeps/> The twigs are reddish and covered in woolly hairs. The leathery leaf blades are often concave and are an oblong lance shape or oval with pointed or rounded tips. The edges are smooth or toothed.<ref name=fna/> The upper surfaces are dark green and lightly hairy when new, losing the hairs over time. The undersides are gray-green and coated in woolly hairs, becoming less woolly with age.<ref name=jeps/> They are usually Template:Convert long, sometimes up to Template:Convert. The acorn grows singly or in pairs. The cup has thick scales and woolly hairs and is up to Template:Convert wide. The nut is up to 3.5 cm with a rounded tip.<ref name=jeps/><ref name=fna/>
Distribution and habitatEdit
It is native to six islands: five of the Channel Islands of California (Anacapa Island, San Clemente Island, Santa Catalina Island, Santa Cruz Island, and Santa Rosa Island) and Guadalupe Island, part of the State of Baja California.<ref name="cnps">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
This species is a relict. Though it is now limited to the islands, it was once widespread in mainland California, as evidenced by the many late Tertiary fossils of the species found there.<ref name="fna" /> Recently, it was found that there was a high genetic variability across many of the Q. tomentella populations, but this variation was not evenly distributed.<ref>Ashley, M.V., J. R. Backs, L. Kindsvater and S. T. Abraham. 2018. Genetic variation and structure in an endemic island oak, Quercus tomentella and mainland canyon oak, Quercus chrysolepis. International Journal of Plant Science 179</ref>
EcologyEdit
Island oak hybridizes with canyon live oak (Quercus chrysolepis).<ref name="fna" />
ConservationEdit
The island oak was listed as an endangered species by the International Union for Conservation of Nature.<ref name="iucn status 19 November 2021" />
The species is threatened by overgrazing from nonnative ungulates. The most rapid declines have occurred on Guadalupe Island.<ref name="iucn status 19 November 2021" /> The trees there are apparently no longer reproducing.<ref name=dela>de la Luz, J. L. L., et al. (2003). On the urgency of conservation on Guadalupe Island, Mexico: is it a lost paradise? Biodiversity and Conservation 12(5), 1073-82.</ref> Feral goats have been abundant on the island for at least 150 years. The animals have eliminated much of the native vegetation and caused extensive soil erosion. Fenced enclosures have been helpful in the early recovery of some of the local flora.<ref>Junak, S., et al. (2003). Esfuerzos recientes de conservación y apuntes sobre el estado actual de la flora de Isla Guadalupe, Baja California, México. Template:Webarchive (Spanish) Presentation at Taller sobre la Restauración y Conservación de Isla Guadalupe [Workshop on Restoration and Conservation of Guadalupe Island]. Instituto Nacional de Ecología, November 13–14, 2003. HTML abstract Template:Webarchive (English)</ref>