The forests of Mt. Kenya (Kenya), a phytosociological synopsis

About 2% of Kenya's area carry still indigenous forests. Those of Mt. Kenya, covering about 2000 km(2) represent nearly 20% thereof and thus the largest natural forest block in the country. A syntaxonomic survey of these forests was performed in a field study between 1992 and 1994 in which 610 releves were established and analysed. Concomitantly, an inventory of the vascular plants of Mt. Kenya was started, which today lists almost exactly 1000 species. For the forests, four syntaxonomic classes including five orders with ten alliances, forty-one associations, forty-seven subassociations and two fazies were described. A synopsis of these is presented in Tables 1-3. The Ocotetea usambarensis form the evergreen submontane forests on the very humid southern, southeastern and eastern slopes of Mt. Kenya at altitudes of between 1500 and 2500 m. They prefer humic Niti- and Acrisols. In small areas of the southwestern slopes evergreen deciduous submontane forests dominate, which were addressed as Brachylaenion huillensis. The montane zone, ranging from 2400 to 2950 m altitude, is represented by evergreen broad-leaved and evergreen xeromorphic forests, combined in the Juniperetea pro-cerae, which prevail on the drier western and northern flanks of the mountain, while the wet regions at roughly corresponding altitudes of between 2300 and 3200 m are the domain of the Sinarundinarietea alpinae, the evergreen montane bamboo forests. The uppermost forest belt ranging from 2900 to 3400 in is produced by the evergreen subalpine forests of the Hagenietea abyssinicae which, at least in one alliance, form a scenic elfin forest. All forest types of Mt. Kenya grow on predominantly inorganic soils, reaching from deep Nitisols in the submontane areas to Andosols dominating in the montane and subalpine zones, whereas Histosols are typical of the moorlands or heather zone which sharply borders the upper treeline. A large-scale vegetation map of the forest belt of Mt. Kenya was produced from the releves on the basis of aerial photographs.