Global warming is endangering the ancient Joshua tree

, July 29 (Xinhua) -- Joshua Tree, which grew in the desert region of southwestern North America, has been on Earth since the Pleus 2.5 million years ago and is longer than mammoths. But a new study suggests that without strong action to curb global warming, the ancient tree species could become extinct by the end of the century.
Joshua Tree National Park in the United States is named after a plant with leaves like a knife, attracting millions of visitors each year. In a paper recently published in the online journal Ecosphere, researchers looked at more than 4,000 Joshua trees in the park and studied the effects of global warming on them in different ways.
found that, at the best possible rate of carbon emissions control, about 19 per cent of joshua tree growth is expected to remain in place by 2070, while at worst it will be only 0.02 per cent.
researchers at the University of California, Riverside, based on data collected by volunteers, found that the species' growing areas are now gradually migrating to higher elevations, lower temperatures and wetter places in the park. In places with higher temperatures and lower humidity, small saplings grow less around adult trees and grow less likely to survive.
part of the reason Joshua trees can survive up to 300 years is that they can store enough water to survive the dry season, but small trees and seeds don't have that much water storage capacity. With global warming, persistent droughts become more frequent, so small trees may not be able to survive the dry season. Researchers believe swift action to reduce greenhouse gas emissions and slow global warming is an important way to save the Joshua tree.