Le mont Kenya, avec une altitude de 5 199 m, est le deuxième sommet du continent africain. C'est un ancien volcan, qui fut en activité de 3,1 millions d'années jusqu'à 2,6 millions d'années avant notre ère et qui s'élevait alors probablement à 6 500 m. La montagne recèle encore les vestiges de douze glaciers, tous en régression rapide, et comporte quatre pics secondaires surplombant des vallées glaciaires échancrées en forme de U. Avec ses sommets accidentés couronnés de glaciers et ses pentes intermédiaires boisées, le mont Kenya représente l'un des paysages les plus imposants d'Afrique de l'Est. La flore afro-alpine fournit par ailleurs un remarquable exemple de processus écologique.
Le Comité a inscrit ce bien au titre des critères (vii) et (ix) comme l'un des paysages les plus imposants d'Afrique de l'Est avec ses sommets accidentés couronnés de glaciers, ses landes afro-alpines et ses forêts d’une grande diversité, qui illustrent des processus écologiques exceptionnels.
[Uniquement en anglais]
At 5,199 m, Mount Kenya is the second-highest peak in Africa. It is an ancient extinct volcano, during whose period of activity (3.1-2.6 million years ago) it is thought to have risen to 6,500 m. There are 12 remnant glaciers on the mountain, all receding rapidly, and four secondary peaks that sit at the head of the U-shaped glacial valleys. With its rugged glacier-clad summits and forested middle slopes, Mount Kenya is one of the most impressive landscapes in East Africa. The evolution and ecology of its afro-alpine flora also provide an outstanding example of ecological processes.
Mount Kenya straddles the equator about 193 km north-east of Nairobi and about 480 km from the Kenyan coast. It was built up by intermittent volcanic eruptions, mainly 3.1-2.6 million years ago. The entire mountain is deeply dissected by valleys radiating from the peaks, which are largely attributed to glacial erosion. The base of the mountain is approximately 96 km wide. There are about 20 glacial tarns (small lakes) of varying sizes and numerous glacial moraine features between 3,950 m and 4,800 m. The highest peaks are Batian (5,199 m) and Nelion (5,188 m).
Vegetation varies with altitude and rainfall, with a rich alpine and subalpine flora. Juniperus procera and Podocarpus species are predominant in the drier parts of the lower zone (below 2,500 m). Cassipourea malosana predominates in wetter areas to the south-west and north-east. However, most of this lower altitude zone is not within the reserve and is now used for growing wheat. Higher altitudes (2,500-3,000 m) are dominated by bamboo on south-eastern slopes, and a mosaic of bamboo and Podocarpus milanjianus, with bamboo at intermediate elevations (2,600-2,800 m), and Podocarpus at higher and lower elevations (2,800-3,000 m) and (2,500-2,600 m). Towards the west and north of the mountain, bamboo becomes progressively smaller and less dominant.
Above 3,000 m, cold becomes an important factor, tree stature declines, and Podocarpus is replaced by Hypericum species. A more open canopy results in a more developed understorey. Grassy glades are common especially on ridges. The lower alpine or moorland zone (3,400-3,800 m) is characterized by high rainfall, a thick humus layer, low topographic diversity and low species richness. Tussock grasses and sedges predominate. The upper alpine zone (3,800-4,500 m) is more topographically diverse and contains a more varied flora, including the giant rosette plants. There are a variety of grasses on well-drained ground and along the streams and river banks. Continuous vegetation stops at about 4,500 m although isolated vascular plants have been found at over 5,000 m.
In the lower forest and bamboo zone mammals include giant forest hog, tree hyrax, white-tailed mongoose, elephant, black rhinoceros, suni, black-fronted duiker and leopard (which have also been seen in the alpine zone). Moorland mammals include: localized Mount Kenya mouse shrew, hyrax and common duiker. There have also been reported sightings of the golden cat. The endemic mole-rat is common throughout the northern slopes and the Hinder Valley at elevations up to 4,000 m. Forest birds include green ibis (local Mount Kenya race), Ayer's hawk eagle, Abyssinian long-eared owl, scaly francolin, Rappel's robin-chat and numerous sunbirds (Nectariniidae). Other birds include scarlet-tufted malachite sunbird, mountane francolin, Mackinder's eagle owl, and the locally threatened scarce swift. The alpine swift and alpine meadow lizard are near endemic.
Mount Kenya is regarded as a holy mountain by all the communities (Kikuyu and Meru) living adjacent to it. They believe that their traditional God Ngai and his wife Mumbi live on the peak of the mountain and use it for their traditional rituals. Source : UNESCO/CLT/WHC