joshua trees


Time for “Creosote Bush” National Park?

It’s not time to rename Joshua Tree just yet, says the author of a new study.

Climate change is threatening the Joshua trees in Joshua Tree National Park all right, according to a new report. But unlike the findings of recently-published study,  this report finds the park’s iconic, spiky namesake is unlikely to completely vacate the premises over the next century.

The new report was funded in part by Joshua Tree National Park, and its author Cameron Barrows, a researcher at UC Riverside’s Center for Conservation Biology, says that he conducted it partly in response to the recent study by Ken Cole of the USGS, which found that the trees would likely be gone from the park within the next 90 years.

“I facetiously say if that was to happen, we’d have to rename the park ‘Creosote Bush National Park’ or something like that,” said Barrows.  “It would be really sad if that’s the case.”
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Joshua Trees Losing Ground, Fast

Joshua trees in Eureka Valley, CA (Photo: Ken Cole, USGS)

Joshua trees, the spiky desert-dwellers that are so iconic to Southern California’s dry country that they got a national park named after them, will likely disappear from 90% of their current range by the end of the century, according to a new study by scientists at the US Geological Survey.

Ecologist Ken Cole, the study’s lead author, said that means no more Joshua Trees in Joshua Tree National Park, which is currently in the southernmost part of the species’ range. It also means elimination of the trees across wide swathes of other parts of Southern California as well as Nevada and Arizona.

Cole and his team used climate models, field work, and the fossil record to project the future distribution of Joshua trees. They compared the projected increase in temperatures for the Southwest (four degrees Celsius, according to a “middle of the road” IPCC scenario) to a similar rapid increase in temperatures nearly 12,000 years ago, at the end of the ice age.

Using fossil sloth dung and packrat midden, the scientists reconstructed how Joshua trees responded to that warming. (Sloths, which are now extinct in the region, and packrats, ate the Joshua tree fruit, spreading the seeds and leaving them behind for the scientists to track.) Continue reading