Morondava in Madagascar, the skyline in Senegal and Kruger national park all have something in common. These places are home to some of the largest trees in the world – baobabs, known to live for thousands of years. These amazing trees have trunks that can reach 30m in circumference or more. In Togo, there is a proverb: “Wisdom is like a baobab tree: no one individual can embrace it.” In many African cultures, the tree is sacred.
There are nine species of baobab in the world, and Madagascar, one of the world’s biodiversity hotspots, is home to six. The African mainland and the Arabian peninsula have two, and Australia has one. Africa’s most notable species is the Adansonia digitata, named after the French botanist Michel Adanson, who undertook an 18th-century exploration of Senegal. He stayed there for five years and contributed to the publication of 1757’s Natural History of Senegal.
Some of the most impressive trees from back then are still around, those from Madagascar especially: for example, the Adansonia grandidieri, or giant baobab, which can reach a height of 30m. It remains the most famous species of baobab in Madagascar. The rarest baobab species in Madagascar are the Adansonia perrieri and A. suarezensis.
All three of these species are threatened and are on the IUCN Red List of Threatened Species, and recent assessments have suggested that the latter two species be reclassified as critically endangered. A. perrieri’s habitat is being lost to agriculture and development, whereas A. suarezensis’s biggest threats to survival are lightning, water logging, black fungus and drought. To make matters worse, the large animal species responsible for carrying seeds may have become extinct and hence reduced the wider distribution of the plant species.
Africa’s “tree of life” may not have much longer left. It forms an integral part in people’s livelihoods. In west Africa, it is also called the “palaver tree” because of its social functions: when there is a problem in the community, meeting under the baobab tree with the chief or the tribesmen would be synonymous with trying to find a solution to that problem; it reinforces trust and respect among members of the community. Its extinction would not simply be an environmental tragedy.
The tree grows in very harsh conditions but is completely adapted to its environment: it sheds its leaves during the dry seasons to reduce water loss; it has a tap root system long enough to reach moisture or even water; and the thick bark protects it from bush fires. From a scientific point of view, the baobab tree is truly a complete plant. The leaves are used in traditional medicine to cure infectious diseases, while the fruit is high in nutrients and is used to make health foods. The seeds yield oil that is prized by the cosmetic industry. The trunk stores water and can be harvested by thirsty travellers.
Yet these highly important species are threatened with extinction, due to climate change and human development. Some species may not survive the next century. While plants have generally adapted to extended droughts, climate change is different, and with the Anthropocene we are already witnessing the loss of these impressive trees.
The greatest irony is that the African continent has hardly produced any greenhouse gases and yet is already bearing the brunt of the vagaries of climate change. Africa’s largest, oldest inhabitants, that have played silent witness to numerous generations, are already paying a heavy price for the environmental crimes of foreign lands.