Editor’s note: This article has been updated to reflect the removal of the trees.
(CNN) – Rising temperatures are leading scientists to worry about a new global threat: ferocious trees.
With daily heat highs over 95 degrees Fahrenheit, California’s blue tree pine is one of the rarest and most threatening trees in the US.
Global warming is set to drive even more of its giant cousins to extinction worldwide in just a few decades, a major study from the journal Science said.
Juniper trees, also known as gingko, are already in decline.
While their giant girth makes them almost impossible to trim, researchers noted that the trees face the prospect of irreversible ecological changes and may need “extinction by other means.”
American wild juniper trees are native to North America and have many of the similar characteristics to the large tree pine.
Tall trees in their prime, they are tall and iconic.
They have thick, heavily wooded trunks which are heavy and constantly shifting, a feature they attract attractive insect larvae.
Juniper trees are also particularly vulnerable to climate change because they live in tightly packed wooded areas, but are “usually not” planted in areas with more available sunlight, said lead author Trevor Chaflin from the University of Nebraska.
That adaptation, he said, likely allowed for rapid adaptation during colder periods, but not so fast when it comes to hot periods.
“The land use strategies that do allow for these trees to adapt are limited to really just the few large historical locations,” he said.
When rain doesn’t fall
To study their impact, Chaflin and colleagues studied juniper trees growing in French Polynesia, the last sun-starved place where they are still present, as they lost about 60% of their trees over the last 10 years.
They also surveyed juniper trees growing in the Sonoran Desert in Arizona, and found the younger trees showed different variations from the older trees.
“Juniper was seen to emerge when low humidity was present, where water was scarce, with evaporation rates much higher, which allows the tree to take in moisture more easily,” the authors wrote.
In other words, this stands in stark contrast to the larger tree pine, which evolved when groundwater was more plentiful.
The paleo-research also showed increasing levels of nitrates in Arizona groundwater “and although juniper is better able to soak up that water, nutrient deposition cannot be predicted.”
The Mexican limber oak has also come under increasing heat stress, the authors said.
While other scientists say the immense plants’ supersized foliage can make them look like ants, the Juniper World Wide Peoples Database, the environmental organization That Island Government, and Forest Enterprise Australia also suggest they could eventually become “a doomhavanian giant” of sorts, because of their inflexible, unwieldy and highly infectious shape.
While these trees may have stronger defenses against extinction, tree pine isn’t faring much better.
It’s the only widespread conifer tree in North America and one of just five or six in the entire world that retain a “true cone,” the researchers say.
It’s also the state tree in Nevada, has been declared endangered in Virginia, and is threatened by extinction elsewhere, according to Scientific American.
In California, it is blamed for a vast forest fire that killed 33 firefighters and a shootout on a training exercise that led to nine deaths in 2002. It also has threatened numerous communities with infestations of destructive bark beetles.
Its colonies typically survive wildfires because of large wood in its trunks and a low percentage of dead wood, said Palaflin. “That’s one of the reasons why there is a fairly low probability that they would go extinct,” he said.
But as temperatures continue to rise, so will the probability of its extinction and the length of its dwindling time on the planet.
“Climate change does appear to be the main driver of the species’ decline,” the authors wrote.