Mysteries of Kilimanjaro

The forests of Kilimanjaro are unusual for two reasons. One is that there is no bamboo zone, unlike the other East African mountains which have extensive bamboo forests. Another is that it was thought that there were only a few rare plants in the Kilimanjaro forests. Research by Hemp has explained the missing bamboo and uncovered a host of rare plants.

The missing bamboo is caused by a lack of elephants. Elephants are needed to create disturbance which encourages bamboo regeneration. However, on Kilimanjaro the lower slopes of the mountain are covered in cultivation preventing elephants from ascending into the forest “There are elephants on the dry side of the mountain” says Hemp “but the valleys are too steep and deep for elephants to traverse to the wet side where the bamboo could grow”. The research demonstrates the complex links between plants and animals and the far reaching effects of changes caused by humans.

The rare plants were found in forest relicts in the deepest valleys of the cultivated lower areas suggesting that a rich forest flora once covered Mt. Kilimanjaro. The plants included a forest tree 40 m high that was new to science. “Kilimanjaro has long been excluded from the tropical rainforest biodiversity hotspot of Tanzania, but these exciting finds change the whole way we think about forest diversity of eastern Africa” said Jon Lovett, an expert in African biodiversity at the University of York.

However, the forests of Kilimanjaro are changing. Fires and logging have had a major impact on the forests. Fire in particular is reducing extent of the highest cloud forests. “The cloud forests are draped in moss and are an important water source as they catch moisture from the mist which shrouds them” explains Hemp “when they are burnt the hydrology of the whole mountain is affected”.