The US Fish and Wildlife Service has been ordered to reanalyze climate change threats to the Western and Eastern Joshua Tree species. Endangered Species Act (ESA) designations as threatened species was previously denied.
Related links:
https://www.desertsun.com/story/news/environment/2025/05/15/joshua-tree-protection-ruling/83658422007/
https://abcnews.go.com/US/federal-court-rules-attempt-withhold-endangered-species-act/story?id=121792589
https://wildearthguardians.org/press-releases/federal-court-sides-with-conservationists-joshua-tree-analysis-unlawfully-sidesteps-climate-science/
https://wildearthguardians.org/brave-new-wild/where-we-work/arizona/inside-the-courtroom-legal-fellow-casey-bage-wins-for-wildlife/
"The court emphasized the need for the FWS to adequately address the threats posed by climate change, including prolonged droughts, increasing fire, and habitat loss, to the Joshua tree."
There are two separate species involved. The species that occurs in the southwestern corner of Utah is the Eastern Joshua Tree, Yucca jaegeriana, and not Yucca brevifolia (which does not actually occur in Utah as was historically thought). In Utah Y. jaegeriana is considered to be criticially imperiled (S1) at the NatureServe state ranking level. The two species may appear superficially to be similar in appearance but they have different growth habits, different leaf lengths, different pollinators, and different fruit and flower morphologies. Y. jaegeriana is for example generally not as tall and is branched compared to the taller, unbranched Y. brevifolia.
Y. jaegeriana in Utah solely occurs in Washington County extending to western Arizona and then from southeastern to southwestern Nevada and then slipping just over the border into southeastern California. Y. brevifolia also occurs in Nevada but farther to north in southwestern Nevada and then extending more into the interior of southeastern California. While there is an area where they meet, they are mostly not sympatric.
Both species are highly threatened by climate change, wildfires, habitat loss and invasive species.
Some journal references and related links:
Recognition of Y. jaegeriana as a species in 2007:
https://scholarship.claremont.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1050&context=aliso#:~:text=Yucca%20brevifolia%20s.s.%20is%20arborescent,5).
https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2023.1266892/full
In July of 2023 California passed the Western Joshua Tree Conservation Act to conserve western Joshua tree and its habitat
https://wildlife.ca.gov/Conservation/Environmental-Review/WJT
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Yucca jaegeriana in Mohave Co AZ 4/25/1986 (Tony Frates photo) |