Study Shows Southern African Ancient Baobabs Are Dying

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In Africa, the baobab tree is known as the “Tree of life”. The Baobab is the largest and longest-living flowering plant in the world. Besides the spectacular look and size, baobab trees offer shelter, food, water and inspiration to local human and animal populations, and a single tree can do so for millenia.

It is tough to imagine that something could suddenly take away the silent giants of the African savannah – ancient trees usually don’t die abruptly. However, that is precisely what happened to some of the oldest and most iconic baobab trees in southern Africa during the 12 years of a tree carbon-dating study – a timeframe which is just a fraction of baobab’s millennial lifespan. A study published in the journal Nature Plants found that 9 of out of 13 oldest, and 5 of 6 most massive baobab trees died during the study, many of them suddenly. For example, Panke, a giant, sacred baobab tree from Zimbabwe which was estimated to be 2,450 years old, had all of its stems fall over and die between 2010 and 2011. The list of “victims” include the Chapman baobab of Botswana and the “Big Baobab” bar tree of South Africa.

Besides the biggest and the oldest trees, the team noted that many other mature baobab trunks died, either entirely or partially. The significance and the fast pace of the baobab die off led the researchers to label it “an event of unprecedented magnitude.” Adrian Patrut, a chemist, survey organizer and co-author of the study, said that “such a disastrous decline is very unexpected. It’s a strange feeling, because these are trees which may live for 2,000 years or more, and we see that they’re dying one after another during our lifetime. It’s statistically very unlikely.

Baobab trees in Madagascar. Photo: Rod Waddington, CC BY-SA 2.0

Baobab trees in Madagascar. Photo: Rod Waddington, CC BY-SA 2.0

Initially, the research paper wasn’t intended to be about sudden deaths of baobabs. The international survey began in 2005 to assess the ages of largest baobab trees by using radiocarbon dating technique. It covered more than 60 trees, out of which more than 20were of exceptional size and age.

The reason behind the die-off is still a mystery. Such a quick demise of old trees is highly unusual, even more so given the regenerative nature of baobab trees – the capability of growing new stems that incorporate themselves into the main trunk structure, and even re-growing bark in the case it is stripped or burned. To add to the mystery, the team claims that the trees show no signs of suffering any known diseases.

For now, the primary suspect is climate change. The region of southern Africa is already warming faster than the average, and there are predictions of sharp increases in temperatures and droughts. It seems that the critical period has already begun. Still, scientists are careful in drawing solod conclusions, and they point out that more research is requiredto confirm that climate change is behind the baobab’s sudden demise.

Voices critical of the study are also heard in the scientific community of South Africa. They suggest that the team’s sample was too small to draw the conclusion of a massive die-off, that they failed to offer proof to exclude disease epidemic, and that the drought should affect all baobab trees and not just the most largest ones, adding suspicion to the climate hypothesis.

However, there is some anecdotal evidence that also point to climate change. For example, Taerou Dieuhiou, baobab fruit harvester from Senegal, commented on a noticeable change in local climate this July: “Normally the rain has started by now, but we have had only one storm. I have to go to other villages. Before, there was enough (fruit) right here.

While its reasons are still uncertain, the impact of the recorded giant baobab deaths are apparent. Besides ecological consequences such as habitat and ecosystem degradation, there are anthropological ones as well. Local African tribes that have based much of their mythology, folklore, and worship around particular trees are now left without the centerpiece of their culture. Additionally, if there is a true baobab crisis happening, it could strike a blow to the newly conceived baobab fruit industry, which supports local communities in a sustainable fashion.

While scientists study and create theories about the die-off, it is likely that the world is now looking at the remaining African giants not only with wonder but with great concern as well.

References

The Study

Patrut A et al. (2018). The demise of the largest and oldest African baobabs, Nature Plants . DOI: 10.1038/s41477-018-0170-5. https://www.nature.com/articles/s41477-018-0170-5

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