Joshua trees vanishing from desert
By JANET ZIMMERMAN, The Press-Enterprise A breeze stirs the silence at Joshua Tree National Park as a red-tailed hawk takes flight from the spiky arm of one of the namesake plants in search of breakfast. It’s a scene that national parks protector Mike Cipra has witnessed many times. Still, he can’t contain his enthusiasm on this early morning outing, despite the gloomy topic he’s discussing with a visitor — the probable extinction of the Joshua tree in the park that bears its name. The ancient plants are dying in the park, the southern-most boundary of their limited growing region, scientists say. Already finicky reproducers, Joshua trees are the victim of global warming and its symptoms — including fire and drought — plus pollution and the proliferation of non-native plants. Experts expect the Joshuas to vanish entirely from the southern half of the state within a century. … Predictions for the fate of the Joshua trees, and the web of life they support, are based on six models of climate change developed by Ken Cole, a biologist and geologist with the U.S. Geological Survey in Flagstaff, Ariz., and plant ecologist Kirsten Ironside of Northern Arizona University. In all of the climate models that looked ahead 100 years, there were no new trees in Joshua Tree National Park, and significant death of existing trees. “With the Joshua tree, it’s like a worst-case scenario. Maybe 80 percent of the current populations will be unable to persist,” he said. …
