Global warming hits bushmen's quivers.

An iconic African desert tree of particular importance in Namibia and South Africa may be slowly succumbing to global warming. The trees, traditionally used by bushmen to make quivers for their arrows, have begun shifting their range southward, which some scientists say is a response to warmer climate conditions.

Wendy Foden, a researcher at the South African National Biodiversity Institute, told Reuters that while studying different sites of quiver trees, she noted that northern trees, closer to the equator, had mortality rates higher than in the South. In addition, trees found at lower, warmer altitudes had higher death rates than those at high elevations.

"If there is no expansion in the quiver trees' range, then models forecast a 76 percent reduction in its population over the next 100 years," Foden told Reuters.

The scattering of seeds either through wind or animal droppings is the only way the species can shift their range, but Foden fears for the individual trees. "If you're a plant, quite literally you are stuck," Foden said. Many of the quiver trees are more than 150 years old but may not survive the increasingly harsh temperatures.