Conservation Status:
Endemic & Endangered
The Yucca Brevifolia plant, more commonly known as the “Joshua Tree” or the “Yucca Palm”, “is confined mostly to the Mojave Desert between 400 and 1,800 m (1,300 and 5,900 ft) elevation. It thrives in Lost Horse Valley in Joshua Tree National Park. Other regions with large populations of the tree can be found northeast of Kingman, Arizona (map) in Mohave County.” (Source)
As such, we believe that it may be a worthy endeavor to preserve one of the few places remaining with significant populations of Joshua Trees.
Furthermore, the Northeast region of Mohave County, where the highest concentration of Joshua Trees are said to be found, is another area we are rezoning for conservation projects such as this, geared specifically towards the Yucca Palm.
However, “Scientists forecast that climate change will dramatically impact the habitat of the western Joshua tree, an endemic species in the Mojave Desert. In 2019, UC Riverside scientists outlined a best and worst-case scenario for Joshua tree habitat in Joshua Tree National Park by the end of the century. They forecast that major efforts to reduce greenhouse gases would save just 19% of suitable tree habitat in the Park. With no reduction in carbon emissions, Joshua trees could well disappear from the Park – with just 2% of suitable tree habitat remaining.
The California Fish and Game Commission will decide in February 2023 whether the western Joshua tree will become the first plant species to be listed as threatened in California due to climate change. It has been temporarily granted protected status during its candidacy period. (Source:)
“Joshua trees are one of the species predicted to have their range reduced and shifted by climate change. Concern remains that they will be eliminated from Joshua Tree National Park, with ecological research suggesting a high probability that their populations will be reduced by 90% of their current range by the end of the 21st century, thus fundamentally transforming the ecosystem of the park.
Wildfires, invasive grasses and poor migration patterns for the trees’ seeds are all additional factors in the species’ imperilment. As an example, approximately 13%—or more than 1.3 million Joshua trees—in one of the densest Joshua tree populations in the world in Mojave National Preserve were killed in the Dome Fire in August 2020. Also, concern exists about the ability of the species to migrate to favorable climates due to the extinction of the giant Shasta ground sloth (Nothrotheriops shastensis) 13,000 years ago; ground sloth dung has been found to contain Joshua tree leaves, fruits, and seeds, suggesting that the sloths might have been key to the trees' dispersal. However, ground squirrels are very effective at moving the seeds long distances.
In March 2022, California Department of Fish and Wildlife conducted a status review of the Western Joshua Tree to determine whether to list the species as threatened under the California Endangered Species Act (CESA). The study showed that the largest threat to Yucca brevifolia was wildfires, that wildfires were a threat to population density of prone areas but not to the limits of the range itself, that several population studies showed Yucca brevifolia was abundant, and that although the southern region of the species' range has been reduced, the trend is that the northern region has been expanding over the last 11,700 years as the North American ice cap melted, allowing the species to occupy its current range. The studies showing reduced population after fires used aerial photography to document populations which would underreport smaller and thus younger trees, as was noted in the review. The review concluded:
Based on the criteria described above, the best scientific information available to the Department at this time indicates that western Joshua tree is not in serious danger of becoming extinct throughout all, or a significant portion, of its range due to one or more causes, including loss of habitat, change in habitat, overexploitation, predation, competition, or disease, and is not likely to become an endangered species in the foreseeable future in the absence of special protection and management efforts required by CESA.
In February 2023, California governor Gavin Newsom's administration proposed a budget trailer bill The Western Joshua Tree Conservation Act to focus on protecting the climate-threatened species and permitting development in the Southern California desert. The proposed legislation calls for a conservation plan for this and other species, that may be threatened by climate change by 2024 and would authorize the California Department of Fish and Wildlife to permit taking a western Joshua tree only under certain conditions.[36] The legislation requires a fee of up to $2500 for the removal, relocation or trimming of limbs of a Western Joshua tree, including dead trees and limbs.
As of 28 June 2023 this bill has been passed by California lawmakers.”
(Source)