The iconic Joshua trees that commonly grow in California deserts could become near-extinct in the future due to the devastating effects of climate change.
This was revealed in a study led by the researchers from the University of California, Riverside on both young and mature specimens of Joshua trees planted across the Joshua Tree National Park, a vast protected area in southern California.
Counting The Joshua Trees
In the study, professional biologists and volunteer community scientists counted up to 4,000 living Joshua trees across the national park that extends into the Colorado and Mojave desert zones. They discovered that plots with a high number of trees have higher annual rainfall level, more soil moisture, and lower temperature compared to plots with less surviving trees.
Older Joshua trees can survive short-term droughts because their shallow root networks absorb more water. Joshua tree seedlings, on the other hand, are much more threatened by harsh weather conditions, resulting in lesser trees that make it to adulthood.
"The fate of these unusual, amazing trees is in all of our hands," said Lynn Sweet, a plant ecologist at the University of California, Riverside and lead author of the study.
She added that the rate the trees would decline depends on efforts to mitigate the deadly effects of climate change.
Iconic Joshua Trees From The Past
Joshua trees or Yucca brevifolia have become known for their long life that can last even up to hundreds of years. This unusual tree species has been around since the Pleistocene era or 2.5 million years ago. In fact, these trees have outlived mammoths and sabertooths.
However, their number has been in constant decline through the years as a result of climate change. Joshua trees are dying because of the dire effects of global warming.
The study suggests that the national park would retain only 0.02 percent of its Joshua tree habitat if no reduction on carbon emissions are made. If drastic changes are executed to reduce heat-trapping gases in the atmosphere, a mere 19 percent of Joshua trees would be around by 2070.
How To Save The Joshua Tree?
Reducing greenhouse gas emissions is the only way to save the Joshua trees. Addressing the constant threat of wildfires would also help. Preserving the Joshua trees would protect animals and insects that depend on them.
"Fires are just as much a threat to the trees as climate change, and removing grasses is a way park rangers are helping to protect the area today," Sweet said in a statement.
The Joshua tree got its name in the early 19th century from Mormons who crossed the Mohave Desert and used the misshapen Joshua tree as a guide. They gave the tree such a name because it reminded them of the biblical prophet Joshua, and they regarded the plant as a spiritual sign of welcome into the Promised Land.
It grows uniquely in deserts such as California's Mohave Desert, Antelope Valley and surrounding areas, and some areas of Arizona, Nevada, and Utah. These trees are commonly found in areas with high elevation of around 1,200 meters. They thrive in freezing temperatures during winter nights, and in very hot, dry summers.
The study is published in the journal Ecosphere.
