'Shocking and dramatic': Some of Africa's oldest and biggest trees dying

Modesto Morganelli
Giugno 13, 2018

Baobab trees commonly form multiple stems, and though the walls of these stems, or trunks, can hold large amounts of water, numerous stems are hollow. In South Africa, one legendary baobob more than 1,000 years old grew to 111 feet and had a hollow so large that it functioned as a pub for two decades.

"Pretty much every baobab tree in Southern Africa is covered in the healed scars of past elephant attacks, which speaks to the trees' awesome fix ability", said David Baum, a University of Wisconsin botanist who is familiar with the new study and contributed to a recent Biodiversity International publication cataloguing the trees' attributes, in an email.

They made the discovery by chance during a study of the biology that enables the baobab to grow so large. Tropical trees in the Costa Rican cloud forest also seem to be dying from rising temperatures. "Statistically, it is practically impossible that such a high number of large old baobabs die in such a short time frame due to natural causes".

A similar fate befell the Platland tree in South Africa, which the authors call "probably the most promoted and visited African baobab".

Scientists are wondering what's behind the mysterious die-off - and are looking at climate change as a likely culprit.

"We report that nine of the 13 oldest ... individuals have died, or at least their oldest parts/stems have collapsed and died, over the past 12 years", the study said.

"When around 70 percent of your 1,500- to 2,000-year-old trees died within 12 years, it certainly is not normal", Erika Wise, a geographer at the University of North Carolina, Chapel Hill, who was not involved in the work, tells The Atlantic. And now seven more of the 13 oldest trees, and five of the six biggest trees, have also died, the researchers report.

Patrut began to notice the deaths during a long-term effort to use radiocarbon dating to gauge the ages of major baobabs. Another famous baobab, the Chapman tree in Botswana, collapsed in 2016. Some of these trees are more than 2000 years old.

"We suspect this is associated with increased temperature and drought", Dr Patrut told BBC News.

Patrut said the dead trunks were only 40% water‚ instead of the 75-80% they should have been. Authors stressed that more research is needed to confirm that.

The latest survey of ancient baobabs suggests climate change may already be affecting the continent's vegetation.

The baobab tree is native to the African savannah.

"The decline and death of so many large baobabs in recent years is so tragic", Baum says.

They suspect climate change-and underground water that's harder for the roots to reach-may have something to do with the trees' demise, but also point out that over each one's life span, it has undergone wetter, drier, colder, and warmer conditions that stress the tree and sometimes kill other plants.

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