Africa’s highest mountain harbours Africa’s tallest trees

In a remote valley of the Kilimanjaro, Andreas Hemp from the University of Bayreuth in Germany and his team discovered a Entandrophragma excelsum specimen of 81.5m height. This equals the former record holder, a Sydney blue gum (Eucalyptus saligna) tree, which died in 2006. In general, tall tree species in Africa may have been overlooked because of a lack of studies outside the biodiversity hotspots. The massive Entandrophragma excelsum trees, considered to be more than 500 years of age, are important for the mountain's ecosystem. However, they are endangered due to illegal logging, threatening their habitat.

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Entandrophragma excelsum at Kilimanjaro (Photo: Andreas Hemp)

Read the full paper here

Abstract: While world records of tree heights were set by American, Australian and Asian tree species, Africa seemed to play no role here. In our study we show that Entandrophragma excelsum (Meliaceae) found in a remote valley at Kilimanjaro has to be included in the list of the world’s superlative trees. Estimating tree age from growth rates monitored by high resolution dendrometry indicates that tall individuals may reach more than 470 years of age. A unique combination of anatomical peculiarities and favorable site conditions might explain their enormous size. The late date of this discovery of Africa’s tallest trees may be due to the comparably low study efforts at Kilimanjaro compared with other biodiversity hotspots. Since only a few square kilometers of this habitat of Entandrophragma are left, Kilimanjaro (and Africa) is about to lose not only a unique biogeographical archive with highly diverse vegetation, but also its tallest trees. The inclusion of these valleys into the immediately neighboring Kilimanjaro National Park would be an excellent and urgent possibility of protection.