In South Africa's Limpopo province, a baobab tree once grew so large and stood so strong that its human neighbours made a decision to do the obvious: They built a pub insidethe living tree's thousand-year-old hollow trunk, which measured more than 45 metres around and enclosed two interconnected cavities.
The ancient baobab trees first sprouted on the African savannah about 1,500 years ago, inspiring awe and becoming an icon on the continent.
Unexpectedly, they found that eight of the 13 oldest and five of the six largest baobabs had either completely died or had their oldest parts collapse. But during their study period, the researchers discovered that the oldest and largest had died.
Speaking of the team's findings, Dr Adrian Patrut of Babeş-Bolyai University in Romania said: "We suspect that the demise of monumental baobabs may be associated at least in part with significant modifications of climate conditions that affect southern Africa in particular".
Plant pathologist Michael Wingfield told Nature that "we know very little about baobab health", and ecologist David Baum said more evidence is needed to conclusively link the spate of deaths to climate change. At various times, these trees have been used as a shop, a prison, a house, a storage barn and a bus shelter. The authors believe that climate change is the culprit. With wide, cylindrical trunks and gnarled branches, the trees appear to have been yanked out of the ground, flipped over and shoved back in, roots in the air. Baobobs grow in unusual ways, often with hollows, making it hard to gauge precise ages, but the research team says the trees in the survey range in age from 1,000 to 2,500 years, reports NPR.
The tree serves as a massive store of water, and bears fruit that feeds animals and humans. The baobab "is famous because it is the biggest angiosperm, and it is the most iconic tree of Africa", Patrut said.
"They can be burnt, or stripped of their bark, and they will just form new bark and carry on growing", it notes. "Such fix growth would lead to an inverted age sequence where wood initially gets older as you move towards the outside of the tree from the hollow".
"When they do die, they simply rot from the inside and suddenly collapse, leaving a heap of fibers, which makes many people think that they don't die at all, but simply disappear", states the website.
Patrut began to notice the deaths during a long-term effort to use radiocarbon dating to gauge the ages of major baobabs. All the dead trees were located in the south of the continent - Zimbabwe, Namibia, South Africa, Botswana, and Zambia.
The baobab is the longest-living, most enormous flowering tree in existence, according to the study. However, the new study concludes that the deaths "were not caused by an epidemic".