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Annex 2. Profiles of Tree Species: Africa
29 Baikiaea plurijuga
Zambezi Teak; Zambezi Redwood
Distribution This
species occurs in Angola, Botswana, Namibia, Zambia and Zimbabwe. Habitat
This species is confined to lowland tropical forest on the Kalahari
sands. Baikiaea plurijuga
is the dominant component of the Baikiaea
forest canopy (White, 1983). Baikiaea forest is the most
extensive deciduous forest on the Kalahari Sand in the
south of the Upper Zambezi basin and B.
plurijuga is essentially
limited to this area (White, 1983). In Zimbabwe, B.
plurijuga is found in higher areas of thicket
on Kalahari sands of the Lupane and Nkayi districts and in higher areas of woodland
thicket on colluvium in the Binga district (Timberlake
et al,
1991). Population Status and Trends
Precise limits of individual populations of the species are
not known but B.
pluijuga is the dominant species
in the Zambesi teak forests the area of which has been measured. In the early
1980s, Zambesi teak forests were reported to cover an
area of 700,000 ha (Mubiti, 1984 in draft CITES proposal, 1986). More
recent surveys have shown that 800,000 ha exist in forest commissioned land in
Zimbabwe (African Regional Workshop, 1996). In
Zambia this forest type formerly covered almost all of the Western Province, the
North-Western Province and the western area of the Southern
Province (CITES draft proposal, 1986). The increased logging
activities of the last fifty years have led to changes in the ecology of the forest;
gaps in the canopy allow for thicket species to develop
(this is especially a problem in Zambia). It is thought that these
changes might inhibit the re-establishment of the Zambezi teak forests (CITES
draft proposal, 1986). These forests are expected to
disappear within 50 years and to be irretrievably diminshed much sooner
(WCMC, 1991). Populations of older individuals (about 500 years old) have now
completely disappeared (African Regional Workshop, 1996).
Although the Zambesi teak forests are threatened, the range
of B. plurijuga
has only been fractionally reduced (African Regional
Workshop, 1996). Grassland quickly replaces the Zambesi teak forests once
they have been cleared, making grassland a more common habitat
for B. plurijuga
(African Regional Workshop, 1996). Populations
in fallow fields and national parks are regenerating well (African Regional
Workshop, 1996). There are thought to be intact populations
in forests in Botswana and Zambia, where levels of exploitation
are less well known (African Regional Workshop, 1996). Regeneration
This species coppices well (African Regional Workshop, 1996).
Role of Species in its Ecosystem
B. plurijuga is
associated with
Entandrophragma caudatum, Pterocarpus
antunesii and
Combretum collinum
(Huckabay, 1986).
Threats This
species is exploited for its timber. The Zambesi teak forest as a habitat type
is undeniably threatened, however, the Baikiaea
thickets that grow on grassland are still fairly widespread and timber
from these thickets can be utilised (African Regional Workshop,
1996). Utilisation The
timber is mainly used in flooring. Locally the species is used for medicinal purposes
and for tanning. B.
plurijuga is not locally exploited for its wood
because it is too hard to cut. Trade
Sales values in Zambia over recent years have been around US$1
million annually, 80% in the domestic market and 20%
from exports. It is one of the two major commercial timber species of Botswana
(WCMC, 1991). Conservation Status
IUCN Threat Category and Criteria: LR:lc (African Regional
Workshop, 1996) Conservation Measures
This species is considered to be a priority for in
situ conservation by FAO, 1984. In
situ conservation stands
have been established in Zambia. The Forest Reserves in Botswana contain B.
plurijuga (African Regional
Workshop, 1996). This species is not suitable for a
plantation programme because of its slow growth and fire sensitivity (African
Regional Workshop, 1996). References
African Regional Workshop, 1996. Conservation
and Sustainable
Management of
Trees project workshop
held in Harare, Zimbabawe, July, 1996. Draft CITES Proposal,
1986. Draft proposal to include Baikiaea
plurijuga on Appendix II of CITES. Huckabay,
1986. cited in the Draft CITES Proposal. (NOT SEEN) Piearce,
1986. cited in the Draft CITES Proposal. (NOT SEEN)
Timberlake, J., Nobanda, N., Mapaure, I, and Mhlanga, L., 1991.
Sites of
interest for
conservation in
various communal lands of N. & W. Zimbabwe.
Vegetation survey of communal lands. Report No.1. WCMC,
1991. Provision of
Data on
Rare and
Threatened Tropical
Timber Species.
pp. 58. White F., 1983. The
Vegetation of
Africa. A descriptive memoir to accompany the
UNESCO/AETFAT/UNSO vegetation map of Africa. Paris:UNESCO.
pp.356. Vegetation type according
to White (1983) 1. Zambezian
dry deciduous forest and scrub forest (Zambezian Kalahari woodland)