Useful Tree Species for Eastern Africa
a species selection tool based on the VECEA Map
White (1983) does not think that there is an objective criterion to separate arid regions from wet regions, although he also mentions that semi-desert areas usually begin to appear where the mean annual rainfall drops below 250 mm, the southern boundary of the Sahara desert corresponds to the 150 mm isohyet and the northern boundary of the Sahara desert corresponds to the 100 mm isohyet. However, he defines semi-deserts ( S ) as areas where the differences in soil characteristics (such as soil colour) are more conspicuous than the vegetation itself, but where the plants are still sufficiently evenly distributed so that the vegetation can be further classified in physiognomic categories such as “semi-desert grassland” and “semi-desert shrubland” (White 1983 pp. 52 - 53). We therefore think that deserts can be defined as “areas where the differences in soil characteristics (such as soil colour) are more conspicuous than the vegetation itself and where the individual plants are never abundant enough in large enough areas to justify the classification of the vegetation as another physiognomic vegetation type such as grassland or shrubland” (see also White 1983 p. 53).
Some areas contain desert for edaphic reasons rather than having rainfall below certain limits. Various edaphic desert areas occur in northern Kenya on extensive stone pavement areas, in mosaic with semi-desert shrubland and dwarf bushland ( S; White 1983 p. 53). An investigation of environmental limits showed that the driest desert areas occur in Ethiopia (see VECEA Volume 5 ). Some areas covered with rock or snow on mountain peaks were classified by VECEA as the subtype of “Afromontane deserts (Ad)”.
F. Gachathi 2009; Figure 5.2 in VECEA Volume 5
The main species recorded to occur within this vegetation type are listed below. Clicking the name of any of these species will open the page for that species on the Agroforestry Species Switchboard. Between brackets the English vernacular name of the species and the documented country distribution of the species (B=Burundi, E=Ethiopia, K=Kenya, M=Malawi, R=Rwanda, T=Tanzania, U=Uganda, Z=Zambia) is provided.
Based on information on species presence in national manifestations of vegetation types, each species was classified as a regionally dominant, characteristic, present or marginal species for a vegetation type (Read more ...)
For more detailed information about the species occurrences see this excel workbook. It provides country specific information on species composition for this vegetation type. It also allows you to select a subset of useful tree species to provide desired products and services. For each species links to a number of websites / databases with information about this species are provided as well.
The table shows the area (km2) of the vegetation type and the percentage of this area explicitly designated for biodiversity, species or landscape protection (A) and areas designated for both protection and sustainable use objectives (B). Only the nationally designated protected areas were included.
|PNV||Area (km2)||A (%)||B (%)|
A) Include the IUCN categories I - IV; B) Include the IUCN categories V - VI and the protected areas without IUCN classification. Read more