africa tallest tree
Africa's tallest tree, Entandrophragma excelsum Hemp et al/Biodiversity and Conservation

Africa's tallest tree has been discovered in a remote valley in Kilimanjaro National Park. The tree, of the Entandrophragma excelsum species, is 81.5m in height and is one of the few giant specimens ever identified on the continent. Scientists say the valleys in which it was found should be considered for urgent protection.

The tree is by no means the world's tallest. That record is held by a coast redwood in northern California which measures 115.6m – just a bit taller than St Paul's Cathedral.

Giant trees are found in many parts of the globe, with record heights set by American, Australian and Asian species. However, there is a distinct lack of trees measuring over 80m in Africa.

To reach these amazing heights, trees need favourable conditions – meaning plenty of access to light and water. It was previously believed that environmental conditions in Africa were not conducive to producing superlative trees.

However, this is not the case. Instead, it appears that the limited study of Africa trees has led to these specimens to be overlooked.

Scientists, reporting their discovery of the African tree in the Springer journal Biodiversity and Conservation, were working in remote valleys near Kilimanjaro National Park. They had been studying the vegetation of Kilimanjaro for over 25 years.

biggest trees
The world's biggest trees Hemp et al/Biodiversity and Conservation

"Recently we recorded extraordinary tall specimens of Entandrophragma excelsum in these gorges," they wrote. They measured trees' height and diameter and made a list of the 10 tallest in the small range they covered, with the biggest reaching 81.5m in height and 2.55m in diameter.

This makes it the biggest indigenous tree ever discovered in Africa. Previously, a Sydney blue gem got up to 81.5m, but this was non-indigenous and it died in 2006.

The area where the trees were found is not currently protected. Scientists say protection should be considered as a matter of urgency, as the number of large old trees in tropical forests is rapidly declining. This has major implications for biodiversity and ecosystems.

"Since only a few square kilometres of this habitat of Entandrophragma are left, Kilimanjaro and Africa are about to lose not only a unique biogeographical archive with highly diverse vegetation, but also its tallest trees," they said. "The inclusion of these valleys into the immediately neighbouring Kilimanjaro National Park would mean an excellent and urgent possibility for protection."