| Abstract: | The East Usambara Mountain forests constitute what is probably one of the richest biological communities in Africa in terms of plant and animal species numbers and endemic taxa. This review presents brief accounts of the flora and of three invertebrate and four vertebrate groups and shows the percentage endemic taxa to vary from 2% (mammals) to 95% (millipedes) as a proportion of the true forest species. Notes are given on the geology, soils, climate and present land use of the Usambaras. Biological richness is considered to be due to long periods of isolation and geological stability coupled with periods of species immigration during times of re-establishment of a continuous forest cover. The nature of the endemic elements is briefly discussed. Evidence is given to show that the forests are subject to increasing pressure from legal and illegal encroachment due to agriculture (tea, cardamon, subsistence) and forestry timber operations. Air photograph analysis shows a forest decrease of some 50% in the vicinity of Amani from 1954 to 1976. The low conservation status of most forest reserves and the lack of detailed knowledge on the distribution, status and biology of the endemic species means present conservation efforts are poor and haphazard. This review calls for greatly increased research inputs and a complete halt to all exploitation of natural forest areas until a long term conservation land use plan can be implemented. |
