Botswana National Botanical Garden
The Natural History Division of the Botswana National Museum, Monuments, and Art Gallery has recently established a National Botanical Garden in Gaborone City. The 13-ha garden is located in the eastern part of Gaborone City, and lies in the village area, which is the oldest and historically, the most important part of the city.
Garden
Development
The garden is still in the initial stages of
development, which is to be carried out in two phases. Phase One consists
of the construction of pathways within the garden, reconstruction of the
fence, and renovation of the historic house. Phase Two will include the
construction of the Natural History Centre, which will provide offices for
the garden staff, as well as a big nursery house.
Climate
The climate of the Botswana National Botanical
Garden can be described as subtropical with relatively cool winters and
warm summers. The mean annual rainfall for Gaborone varies between 375 mm
and 525 mm. Of this total, 51% falls during the summer months, 33% in spring,
12% in autumn, and only 6% in winter. January is in general the wettest
month of the year. The average maximum daily temperature ranges from 22.2°C
in June to 32.6°C in January.
Vegetation
The Botswana National Botanical Garden is the
first botanic garden in the country, and the site where the garden is located
is reasonably pristine land. About 98% of the garden is covered by naturally
growing vegetation, which comprises woody plant species and a few shrubs;
only 2% of vegetation has been introduced as collections from different
parts of the country. Some alien species are also found in the garden; they
will be removed. Natural rock outcrops found within the garden form a habitat
for Combretum molle, Elephantorrhiza burkei, Ficus
abutilifolia, Ficus ingens, and Pappea
capensis. Other
indigenous woody plants occurring elsewhere in the garden include Acacia tortilis, Boscia foetida, Boscia albitrunca,
Dichrostachys cineria, Diospyros lycioides, and Grewia species.
Garden
Areas
The Botswana National Botanical Garden is divided
into the following six areas, which cover different vegetation types and
regions of the country:
Area
One: Chobe
vegetation
Area
Two: Okavango
and Pans vegetation
Area
Three: Mopane
woodland
Area
Four: Northeastern
Kgalagadi
Area
Five: The
Mashatu vegetation
Area
Six: Southwestern
Kgalagadi
Area
One
Area One is planned to represent plants
from the Chobe region, which is in the far northern part of the country.
So far, only a few Chobe plants have been introduced. Unfortunately, some
of the plants collected did not survive, owing to new climatic conditions.
The remaining plants are Adansonia
digitata,
Area
Two
Area Two consists of plants collected from
the Okavango and Pans. The Okavango region is in the northern part of Botswana,
where most of the pans also occur; there are also pans in the western part
of the country. Currently Area Two is dominated by naturally growing plants
typical of the southern part of the country. Only a few plants have been
introduced in this garden area, including Gardenia
volkensii
Area
Three
Area Three hosts Mopane woodland plants,
which are well established in the garden. Other plants introduced in the
area are various Aloe species and these
are doing well. Plants introduced in this area were collected from the central,
eastern, and northeastern parts of the country. The following species in
Area Three are doing exceptionally well: Acacia
nigrescens,
Area
Four
Area Four represents plants collected from
northeast Kgalagadi. Several plants have been introduced, but not all of
them survived the new conditions and habitat they were subjected to. Plants
in Area Four that survived the new environment are Aloe
marlothii,
In
addition to the species introduced into the area, Acacia
tortilis
Our objective is to collect as many plants from northeast Kgalagadi as possible for cultivation in Area Four.
Area
Five
Area Five will be further developed to represent
the Mashatu vegetation, from the far eastern part of the country. So far
only a few species have been collected and cultivated in the area, including
Aloe marlothii
Steganotaenia araliacea, Acacia xanthophloea, and Bolusanthus speciosus were also introduced to Area Five, but did not survive because of an unfavourable environment. Our aim is to study the cultivation techniques of these species and to collect replacement specimens during another field trip.
Area
Six
Area Six represents the vegetation of the
western Kgalagadi region, and only a few plants have been collected from
this region. Our objective is to have as many specimens as possible from
the western Kgalagadi region. The few plants that were introduced into Area
Six included Elephantorrhiza
elephantina,
Both
the Elephantorrhiza elephantina and the
Terminalia sericea died. Plant species growing naturally in the area, which are
also common in the western Kgalagadi vegetation, are
Medicinal
Section
The garden also has a small plot where some
herbal tea and medicinal plants of Botswana—Lippia species
and Osteospermum muricatum —have
been introduced.
Baines' baobabs, Nxai Pan National Park, Botswana, by Angela Versari
—by Diphetogo Menyatso
SABONET
News 6.2:108
