The conservation of the forest resources of eastern Africa: past influences, present practices and future needs - Biogeography and Ecology of the Rain Forests of Eastern Africa - page 294

culivation. Myers (1979) suggests that forest area
in Kenya was four imes greater at the beginning
of the century.
A further factor that emerges from these
studies is the extreme fragmentation of the forest
cover. In Tanzania the largest blocks of natural
closed forest are: Shume-Magamba 80 km2
(West Usambaras), Hundu-Kisiwani 110 km2
(East Usambaras), Luhomero 150 km2 (Uzung-
was) and the rings of forest on Mounts Kiliman-
jaro and Meru. The Atlas of Ta nzania
(Government of Tanzania, 1976) shows a net-
work of over 220 small separate closed forest
reserves, indicaive of a fragmented resource.
Evidence in this topic and in this chapter suggests
that the resource is not fragmented owing to
physical or biotic habitat factors, but to the
historical impact of man's clearing and burning.
Much of the forest cover is reserved in both
Kenya and Tanzania, but there are major excep-
ions, some of great ecological and biological
importance. The Taita Hills in Kenya are an
example of major forest values sill ungazetted.
Most coastal thicket and forest is not reserved,
including large areas of tall dry coastal evergreen
forest on the Kichi Hills in Rufiji and Kilwa Dis-
tricts ofTanzania (Vollesen, 1980; Rodgers et al.,
1985b; Burgess et al., 1990), which do have
endemic tree taxa such as Pteleopsis apetala Vol-
lesen and Tessmannia densloa Harms. Kisiju
Forest, on the coast south of Dar es Salaam, may
have Tanzania's last surviving fragments of gum
copal (Hymenaea vermcosa Gaertn.) forest (Haw-
thone, 1984; Rodgers, Hall & Mwasumbi 1985a;
Rodgers, 1992). Many of the surviving riverine
forests of Tanzania are not reserved. The highly
battered and wafer-thin forest along the Great
Ruaha River is a good example, where the ever-
green forest has acted as a migratory pathway
through exremely arid Euphorbia-Commiphora
scrub for colobus monkeys, birds and plant taxa,
as well as providing past protecion to an import-
ant water source. Planning for the Uzungwa
Naional Park led to the inclusion of dry forest
and woodland communiies north to the Great
Ruaha River J. Boshe, personal communicaion
1989). Most riverine forest along the Umba River
bordering Mikomazi Game Reserve has been

cleared since 1965, leading to local exincion of
colobus monkeys.
This topic is largely about forest resources, but
it must not be forgotten that these forests contain
important animal communities. Table 14.4 docu-
ments this resource for the mammals in the
easten African orests (see also Kingdon &
Howell, Chapter 11). The birds are discussed by
Stuart et al. (Chapter 10). A very readable account
of animal and plant life in East Africa's frag-
mented forests is Kingdon's (1990) topic, Is land
Ar ica .
Rodgers, Owen & Homewood (1982) stress the
relative low diversity of the Eastern Arc forests for
mammals and suggest that this is atributable to
the distance and isolaion of the forests from the
principal refugia of Zaire-Uganda. Fragmen-
tation and isolaion has, however, led to much
geneic difereniation at species and subspecies
levels. The biological consequences of fragmen-
taion, and management to reduce such impact
(see Saunders, Hobbs & Margules, 1991) are dis-
cussed in later secions (pp. 303-5).

The ype of orest cover

East Africa's forests, which have been formed
under a great variety of physical factors, are
diverse in composiion and structure; this diver-
sity has been described in detail elsewhere in this
volume (e.g. Lovett, Chapter 4; Hoffm an, Chap-
ter 6; Kingdon & Howell, Chapter 11; Stuart etal.
Chapter 10). Rodgers et al. (1985b) quaniy
Tanzania's forest cover in terms of three alitude
classes and two rainfall regimes. Summaries of
broad forest types may be found in White (1983),
Hedberg & Hedberg (1968) and Lind & Mor-
rison (1974). Beentje (l 990a) describes Kenyan
forests in detail.

Monitoing trends in orest cover

Neither Kenya nor Tanzania has had detailed
forest monitoring programmes in the past, and
there is thus no accurate record of the rate and
pattern of deforestaion. Some esimated data are
given for Uganda by Hamilton (1984). Esimates
and spaial presentaion of forest cover by Doute