Several indigenous tree species were identified as under threat in the SADC region. The threat has been on individual species, whole forest ecosystems and general forest degradation and genetic impoverishment of remnant tree species. The threats are from uncontrolled forest fires, conversion of land to agriculture, droughts, pests and diseases, habitat loss to invasive alien tree species and infrastructural development (urban, roads, dams, etc), prospecting for mineral and mining, unsustainable exploitation. Although the level of threat varies for the different species in the different countries, the following species are regarded as under moderate to severe threat of genetic impoverishment as a result of forest degradation: Adansonia digitata, Afzelia quanzensis, Allanblackia ulugurensis, Baikiaea plurijuga, Beilschmedia kweo, Bivinia jalbertii, Brachylaena huillensis, Brachystagia spiciformis, Celtis Africana, Cephalosphaera usambasensis, Dalbergia melanoxylon, Diospyros mespiliformis, Englerodendron usambasensis, Endandrophragma excelsum, Enzepharlotos goetzi, Harpagophyton procumbens, Hyphaene petersiana, Hyophorbe amaricaulis, Ilex mitis, Isoberlinia scheffleri, Juniperus procera, Khaya onthotheca, Kirkia acuminata, Leucosidea sericea, Millettia stuhlmanii, Milicia excelsa, Ocotea usambasensis, Odyendea zimmermannii, Olea europea, ssp. africana, Phoenix reclinata, Podocarpus milanjianus, Protea caffra, Pterocarpus angolensis, Pterocarpus mildebraedii, Rhus lancea, Securidaca longipedunculata, Spirostachys africana, Strychnos mitis, Warbugia salutaris, Widdringtonia nodiflora (syn. W. whytei and W. cupressoides)
In Mauritius for example, only one specimen of Hyophorbe amaricaulis is left in the country, while in Zimbabwe, it is estimated that the remaining W. salutaris are no more than a hundred trees in the wild. Bivinia jalbertii is also under severe threat in Zimbabwe as only a relic stand of about a thousand trees of this species are now left in the Nyoni hills near Ngundu where a multi-million dollar dam construction project (Tokwe-Mukosi dam) right nearby could seal its fate. Two diseases, mukwa die-back (Fusarium oxysporum) on P. angolensis and baobab sooty on A. digitata are threatening these tree species in their native range (van Wyk et al., 1993). A scale insect, Aspidoproctus glaber has caused extensive die back and even tree death of Brachystegia spp. and Julbernardia globiflora in a near pristine miombo woodland covering over 60 000 ha in Zimbabwe (Mushongahande and Mazodze, 1996). In South Africa and Zimbabwe, invasive alien tree species have invaded an area of 10.1 million ha and 450 000 ha respectively (Nyoka, 2003).
