Eastern Arc moist forest flora - Biogeography and Ecology of the Rain Forests of Eastern Africa - page 35

on metamorphosed limestone at Kimboza east of
the Uluguru and on the Mahenge Mountains.
Forest species grow on the basic soils of termite
mounds in grassland in the southen Uzungwa
outside normal forest limits (Lovett & Gereau,
1990).

forest (2100-2400 m). Wetter and drier ypes of
lowland and submontane forest were recognised.
Classification terminology of Eastern Arc for-
ests becomes further confused when phytogeo-
graphic systems are used. Monod (1957)
originally proposed a sraightforward system
whereby the forests of easten Africa were con-
sidered an easten domain of the Guineo-Con-
golian forests of West and Central Africa. This
included both montane and lowland forests below
the high altitude Afroalpine region of Hauman
(1955), which was composed of grassland with
giant Lobelia and Senecio. Troupin (1966) com-
bined Hauman's Afroalpine region with Hed-
berg's Ericaceous belt, included Hagenia and
bamboo forest, and put them together in an Afri-
can montane region; forests below 2000 m
remained in the Guineo-Congolian region. White
(1970) proposed an Afromontane region with an
upper limit corresponding to Hedberg's Alpine
belt, and a lower limit of 1065-1525 m depending
on local condiions. Forests below White's
Afromontane region were sill considered part of
the Guineo-Congolian region, though they were
regarded as an easten 'Usambara-Zululand'
domain. White (l 978a) divided his Afromontane
region into seven regional mountain systems on
the basis of distances between mountains, which
breaks up the Easten Arc, into a southen
Uluguru-Mulanje and a northen Usambara-
Imatong group; he also emphasised that the
Aroalpine region was not very disinct from the
Afromontane region. This approach was followed
by Denys (1980), who found support for the
north-south Easten Arc divisions in a study of
species distribuion maps. White (1983) truncated
the Guineo-Congolian region at Lake Victoria
and regarded easten African forests below the
Afromontane region as part of an easten coastal
Zanzibar-Inhambane region.
The main problems with these various
terminologies are as follows.

Classiicaion of the Easten Arc orests

A number of different classificaion systems and
terminologies have been proposed for the forests
of easten Africa. Moreau (1935) divided the
Usambara mountain forests into lowland, inter-
mediate and highland. Pitt-Schenkel (1938),
working in the West Usambara Magamba forest,
refered to Moreau ' s 'Highland Evergreen Forest'
as 'Warm Temperate Rain Forest' and listed 12
other synonyms for the same forest type. The
term 'Temperate' to describe tropical African
montane forests has also been used more recently
by Donald & Theron (1983). Hedberg (1951) in a
study of high alitude vegetaion on the highest
mountains of East and Central Africa described a
Montane forest belt above 1700-3000 m, below a
heath-like Ericaceous belt. Hedberg's montane
forest belt had drier and wetter types, and zones
of bamboo and Hagenia. At the CCT /CSA
(1956) meeing at Yangambi a set of terms for
African closed forest formaions was proposed.
This divided moist forests into drier and wetter
types at low to medium and higher alitudes; the
higher altitude forests were called montane.
Greenway (1973) published a vegetation classi-
ficaion for East Africa which was originally pro-
posed in 1943 but was not available at the
Yangambi meeing. In this classiicaion lowland
forest occurred between sea level and 1200 m;
above this the forest was described as upland for-
est. Both lowland and upland forest had wetter
and drier types. For Malawi, Chapman & White
(1970) divided the forests into lowland (up to
1370 m), submontane (1370-2290 m) and mon-
tane (mostly above 1980 m). The term submon-
tane forest was also used by Pocs (1976b, c) who
divided the Uluguru forests into lowland (below
500 m), submontane (800-1500 m), montane
(1500-1850 m), montane mossy or upper mon-
tane forest (1850-2400 m) and subalpine elfin

1. The term 'temperate' is not appropriate
for the ropical African montane forests as
they have primarily ropical affiniies and
origins. This is in conrast to the heath
and grassland vegetaion above the forest