When researchers set out to investigate the structure, growth and age of Africa's iconic baobab trees—the largest and longest-living flowering trees in the world—they received a devastating surprise. Many of the oldest, largest baobabs were dead or dying. The final study, published in Nature Plants Monday, reported that nine of the 13 oldest and five of the six largest African baobabs had entirely or partly died during the research period from 2005 to 2017. The oldest was 2,500 years old. "It is definitely shocking and dramatic to experience during our lifetime the demise of so many trees with millennial ages," study co-author Adrian Patrut of the Babes-Bolyai University in Romania told AFP. The researchers studied every known large African baobab in Africa, on islands off its coast or outside Africa for a total of more than 60 trees. All of the dying trees were found in the southern African countries of Zimbabwe, Botswana, South Africa, Zambia and Namibia. Baobabs survive the dry Savannah by storing water in their large trunks, but researchers thought conditions were now getting too dry even for them. The cause of the trees' deaths was unknown, but was not attributed to disease, and the deaths of the oldest trees coincided with an uptick in mortality in other mature baobabs. The researchers therefore hypothesized that the impact of climate change on Southern Africa was to blame. "We suspect this is associated with increased temperature and drought," Patrut told BBC News. The researchers also found that baobabs are always multi-stemmed: They grow new stems as they age the way other trees sprout branches. Of the endangered old and large trees, four had seen all stems collapse and topple entirely, while six had seen only some of their stems collapse and die. The report also memorialized the oldest, largest and most famous trees to die. The oldest, Panke, was a sacred tree in Matabeleland North, Zimbabwe. At around 2,500 years old, it was not only the oldest baobab, but the oldest angiosperm, or flowering tree, in the world. The largest, the Platland tree or Sunland baobab, was also probably the most visited and promoted tree in Africa. It had a total wood volume of 501 cubic meters (approximately 17,692.6 cubic feet) and was also the largest angiosperm. It was located in the Limpopo province of South Africa. The most famous, the Chapman baobab, was located in Botswana's Makgadikgadi Pans. It was named for South African hunter James Chapman who visited it in 1852. Baobabs are important to the ecosystems and cultures of Southern Africa. They provide nesting sites for birds, according to BBC News, and AFP reported that both animals and humans eat their fruit. Humans also boil their leaves for food and medicine and use the bark for rope, baskets, hats and cloth, AFP noted.<doc-sep>For centuries – millennia even – they've towered over the savannah like giants from another world, but their long, almost immortal watch is at last beginning to fade. The African baobab, the largest and longest-living tree among all angiosperm (flowering) plants, is in the midst of a deadly crisis, with new research finding several of these ancient trees have recently died or are in the process of internal collapse. "It is definitely shocking and dramatic to experience during our lifetime the demise of so many trees with millennial ages," chemist Adrian Patrut from the Babeș-Bolyai University in Romania explained to The Guardian. To investigate how baobabs – aka the 'tree of life', owing to its ability to retain water – can grow to such impressive sizes, Patrut and his team began researching them in 2005, analysing over 60 of the largest and potentially oldest specimens in Africa. (dennisvdw/iStock) Trees usually have their age counted by tree-ring dating (dendrochronology), but Patrut says the unusual biology of baobabs prevents this. That's because, according to Patrut, we're not looking at a conventional, singular trunk here – but a bunch of them, clumped vertically like a kind of cloistered mini forest. "The majority of baobabs start growing as single-stemmed trees," the authors explain in their paper. "Over time, single-stemmed individuals become multi-stemmed, owing to the baobabs' ability to periodically produce new stems, in much the same way other tree species produce branches. With this special ability, baobabs develop architectures of increasing complexity over time." While investigating those complex architectures, the team found these woody structures were rapidly becoming condemned: eight of the 13 oldest baobabs – and five of the six largest – either died since 2005, or had begun internal collapse. "Statistically, it is practically impossible that such a high number of large old baobabs [could] die in such a short time frame due to natural causes," Patrut told National Geographic. (Feans/Flickr) But if we're not looking at natural causes here, what's behind this sudden downfall? The researchers don't know for sure, but they describe the spate of high-profile deaths – the end of trees so grand they each had their own names – is an event of "unprecedented magnitude" that likely points to climate change. "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," the team writes. "However, further research is necessary to support or refute this supposition." While the science of baobab biology is not yet settled – with at least one ecologist calling out Patrut's multi-stem hypothesis as a "fantasy" – nobody disagrees that it's heartbreaking to see these great, old lives pass into memory like this. If climate change is truly the culprit, this is just the latest evidence of how our careless addiction to carbon is damaging the sensitive ecosystems around us in ways that could be irrevocable. "It is very surprising to visit monumental baobabs, with ages greater than 1,000 to 2,000 years, which seem to be in a good state of health, and to find them after several years fallen to the ground and dead," Patrut told National Geographic. "We felt as if we were the ones outliving the baobabs, instead of them outliving many generations of humans." The findings are reported in Nature Plants.<doc-sep>(CNN) — Some of the oldest and biggest baobab trees in Africa have died recently, becoming the latest possible victims of climate change, according to a study published in the journal Nature Plants on Monday. The trees – located in Zimbabwe, Namibia, South Africa, Botswana and Zambia – have died completely, or partly, according to the study. Some of them dated back to the times of the ancient Greeks. Researchers found that nine of the oldest 13 baobab trees and five of the six biggest ones have partially or completely perished in the past 12 years. The baobab tree, often referred to as the “tree of life” for its ability to produce nutrient-rich fruit even during Africa’s harsh dry season, can live to be 3,000 years old, and can grow as wide as the length of a bus. In the past, they have been used as a prison, a barn and a bus shelter, according to the website of Kruger National Park in South Africa. Steve Brigman/Shutterstock The Chapman baobab tree in Botswana, which collapsed in 2016. When they’ve lost their leaves, the trees appear to be upside-down, with their branches resembling roots that extend upward. Given their age and their resilience to the often-harsh weather conditions in Africa, they have been the source of local stories and legends. “It is definitely shocking and dramatic to experience during our lifetime the demise of so many trees with millennial ages,” Adrian Patrut of Babeș-Bolyai University in Romania, one of the study’s co-authors, told AFP. The Panke tree, which was oldest of the dying trees, lived for 2,500 years until its stems collapsed in 2010-2011, according to the study. It’s still unclear what is driving the baobab deaths. The authors believe that climate change is the culprit. “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. However, further research is necessary to support or refute this supposition,” the authors wrote.<doc-sep>Some of Africa’s oldest and most unusual trees have mysteriously started dying – and scientists think climate change may be to blame. An exceptional number of baobabs, which are known to live for up to 2,000 years – and maybe longer – have died in the past 13 years, experts found. A cavity in the Platland tree in South Africa housed a bar for more than a decade (Adrian Patrut) Baobabs, also known as “dead rat” trees, after the shape of their fruit, are among the most distinctive plants in the world, with up to seven giant trunks that can look like pillars. They start growing as a single trunk but over time develop others. Thanks to their size, they contain hundreds of square metres of wood but have massive hollow centres. Adrian Patrut, a Romanian professor of inorganic and radiochemistry, and colleagues used radiocarbon dating to analyse more than 60 of the largest and oldest baobab trees in Africa to try to find out how the trees could grow so large. To their surprise, they found that since 2005, nine of the 13 oldest, and five of the six largest baobabs had either died or had their oldest parts collapse. Their paper, published online this week in Nature Plants, suggests that climate change may be affecting the ability of the trees to survive. Prof Patrut told The Independent that El Nino - warm currents that travel east across the Pacific Ocean - had increased dry conditions over the past 20 years, leading to drought in southern Africa, which was thought to be one factor in the trees' demise. A baobab in Bissau, west Africa, with a cavity used by people for hanging washing (Getty) The dead trunks were found to contain only 40 per cent water, instead of the 75-80 per cent they should have. The extreme drought episodes meant the trunks could no longer support the tree's weight so they collapsed, he said. Baobabs have a unique ring-shaped structure comprising multiple stems and trunks, often of different ages, that may fuse together to form a closed circle, or remain open. The experts found that in some cases all the trunks had died suddenly at the same time. The most high-profile victim of the phenomenon is the Chapman's baobab in central Botswana, parts of which dated back 800 years, while others were 1,400 years old. A national monument of Botswana and a tourist attraction, it was more than 82ft in circumference. On January 7 2016, its six trunks all collapsed and died. “The deaths of the majority of the oldest and largest African baobabs is an event of an unprecedented magnitude,” the authors wrote. “These deaths were not caused by an epidemic and there has also been a rapid increase in the apparently natural deaths of many other mature baobabs. “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. However, further research is necessary to support or refute this.”<doc-sep>
Some of Africa’s oldest and biggest baobab trees have abruptly died, wholly or in part, in the past decade, according to researchers. The trees, aged between 1,100 and 2,500 years and in some cases as wide as a bus is long, may have fallen victim to climate change, the team speculated. “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,” they wrote in the scientific journal Nature Plants, describing “an event of an unprecedented magnitude”. “It is definitely shocking and dramatic to experience during our lifetime the demise of so many trees with millennial ages,” said the study’s co-author Adrian Patrut of the Babeș-Bolyai University in Romania. Among the nine were four of the largest African baobabs. While the cause of the die-off remains unclear, the researchers “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”. Further research is needed, said the team from Romania, South Africa and the United States, “to support or refute this supposition”. Between 2005 and 2017, the researchers probed and dated “practically all known very large and potentially old” African baobabs – more than 60 individuals in all. Collating data on girth, height, wood volume and age, they noted the “unexpected and intriguing fact” that most of the very oldest and biggest trees died during the study period. All were in southern Africa – Zimbabwe, Namibia, South Africa, Botswana, and Zambia. The baobab is the biggest and longest-living flowering tree, according to the research team. It is found naturally in Africa’s savannah region and outside the continent in tropical areas to which it was introduced. It is a strange-looking plant, with branches resembling gnarled roots reaching for the sky, giving it an upside-down look. The iconic tree can live to be 3,000 years old, according to the website of the Kruger National Park in South Africa, a natural baobab habitat. The tree serves as a massive store of water, and bears fruit that feeds animals and humans. Its leaves are boiled and eaten as an accompaniment similar to spinach, or used to make traditional medicines, while the bark is pounded and woven into rope, baskets, cloth and waterproof hats. The purpose of the study was to learn how the trees become so enormous. The researchers used radiocarbon dating to analyse samples taken from different parts of each tree’s trunk. They found that the trunk of the baobab grows from not one but multiple core stems. According to the Kruger Park, baobabs are “very difficult to kill”. “They can be burnt, or stripped of their bark, and they will just form new bark and carry on growing,” it states. “When they do die, they simply rot from the inside and suddenly collapse, leaving a heap of fibres.” Of the 10 trees listed by the study authors, four died completely, meaning all their multiple stems toppled and died together, while the others suffered the death of one or several parts. The oldest tree by far, of which all the stems collapsed in 2010/11, was the Panke tree in Zimbabwe, estimated to have existed for 2,500 years. The biggest, dubbed Holboom, was from Namibia. It stood 30.2 metres (99 feet) tall and had a girth of 35.1 m.