Copyright 2010 Peter Martin Rhind Plant Formations in the Zambezian BioProvince
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- Copyright © 2010 Peter Martin Rhind
- Zambezian Miombo Woodland
- Zambezian Mopane Woodland
- Zambezian Dry Semi-Deciduous Baikiaea Forest
- Zambezian Chipya Woodland
- Zambezian Dambo Grassland
- Zambezian Flood Plain Grassland
- Zambezian Submontane and Montane Grassland
| Copyright © 2010 Peter Martin Rhind
These broadly divide into moist and dry forest, but only fragments of each type remain. The remaining relic areas of moist evergreen forest occur in the high rainfall areas of Zimbabwe such as the Lusitu River valley and Chimanimani Mountains. The principal tree species here include Blightia unijugata, Erythrophleum suaveolens, Melanodiscus oblongus, Zanha golungensis, the endemic Bersama swynnertonii (Melianthaceae) and the near endemic Curtisia dentate (Curtisiaceae), while common lianas include Mascarenhasia variegata, Paullinia pinnata and the endemic Saba comorensis (Apocynaceae). Further north on the slopes of Inyangani the endemic Maranthes floribunda (Chrysobalanaceae) becomes one of the more important trees together with Filicium decipiens, Pachystele brevipes and Xylopia aethiopica. Chirinda Forest is another example. Here common trees include Craibia brevicaudata, Diospyros abyssinica, Khaya nyasica, Lovoa swynnertonii, Stychnos mitis and Trichilia dregeana, while lower story shrubs and small trees commonly include the endemic Tabernaemontana ventricosa (Apocynaceae). The common lianas are Landolphia kirkii and Clerodendron swynnertonii, while the ground layer typically includes various shade tolerant grasses such as Leptaspis cochleata, Olyra latifolia and Oplismenus hirtellus. In Zambia the remaining patches of moist forest contain yet another assemblage of species. Among the more dominant trees are Canarium schweinfurthii, Fagaria macrophylla, Pachystela brevipes and the endemic species Hannoa kitombetombe (Simaroubaceae). Some of the endemic plants more or less confined to moist evergreen forests include the woody climber Artabotrys stalzii (Annoaceae), the evergreen shrub Combretum coriifolium (Combretaceae), the evergreen tree Maranthes goetzeniana (Chrysobalanaceae) and the annual herb Phyllanthus
The remaining fragments of dry evergreen forests are mainly confined to northern parts of the BioProvince. They have a simpler structure and are relatively poor floristically, and their floral composition varies greatly from place to place. Some of the more common trees include Berlinia giongii, Cryptosepalum pseudotaxus, Daniella altsteeniana, Marquesia
main lianas include Artobotrys monteiroae, Combretum microphyllum and the near endemic Uvaria angolensis (Annonaceae) and there is often a dense under storey of evergreen thicket in which Diospyros undabunda is often conspicuous, while other small trees include Anisophyllea boehmii, Canthium anomocarpum, Diospyros batocana, Kirkia
and Kotschya strobilantha. Endemic plant species specific to these drier forests include the shrubs Beilschmiedia gilbertii (Lauraceae shrub), Popowia gracilis (Annoaceae)
and the perennial herb Gutenbergia polytrichomata (Asteraceae).
The Zambezian endemic plant species more generally associated with evergreen forests include trees such as Allophylus chirindensis (Sapindaceae), Bombax mossambicensis (Bombacaceae), Canthium ngonii (Rubiaceae), Dasylepis burtt-davyi (Flourcourtiaceae), Garcinia mlanjiensis (Hypericaceae), Hannoa kitombetombe (Simaroubaceae), Lasiodiscus usambarensis (Rhamnaceae), Macaranga mellifera (Euphorbiaceae), Morinda asteroscepa (Rubiaceae), Psydrax whitei (Rubiaceae), Tannodia swynnertonii Copyright © 2010 Peter Martin Rhind
(Euphorbiaceae), Trichoscypha ulugurensis (Anacardiaceae) and Vepris stolzii (Rutaceae), and shrubs such as Acalypha chirindica (Euphorbiaceae), Aeschynomene stolzii (Fabaceae), Combretum stocksii (Combretaceae), Dombeya brachystemma (Sterculiaceae), Erythrococea ulugurensis (Euphorbiaceae), Garcinia acutifolia (Hypericaceae), Monodona grandidera (Annoaceae), Ochna kirkii (Ochnaceae),
(Anacardiaceae), Vepris whitei (Rutaceae) and Vernonia exertiflora (Asteraceae). These trees and shrubs support many climbers and lianas including the endemic Cissus faucicola (Vitaceae), keetia foetida (Rubiaceae), Popowia chasei (Annoaceae), Ritchiea gossweileri (Capparaceae) and Tragiella anomala (Euphorbiaceae), together with many endemic epiphytes particularly orchids such as Aerangis appendiculata, A. distincta, A. montana, A. oligantha epiphyte, A. splendida, Angraecopsis malawiensis, Angraecum minus, Bulbophyllum ballii, B. baronis, B. stolzii, Diaphananthe microphylla, D. stolzii, Liparis nyikana, Mystacidium tanganyikense, Polystachya goetzeana, P. greatrexii, P. moreavae, P. purpureobracteata, P. suaveolens, P. subumbellata, and the near endemic Stenoglottis zambesiana (Orchidaceae). The ground layer also includes a number of endemic orchids such as Disperis bifida, Habenaria pubidens, H. pubipetala, H, trachypetala and Nervilia pectinata (Orchidaceae), together with other endemic herbs like Dorstenia zambesiaca (Moraceae), Pentas schumanniana (Rubiaceae) and Strepocarpus erubescens (Gesneriaceae).
Throughout much of this BioProvince, miombo is the prevalent woodland type. It is deciduous or semi-deciduous and usually dominated by 19 species of Brachystegia such as the endemic B. bakerana and B. tamarindoides (Fabaceae) and the related
canopy species are Afzelia quanzensis, Anisophyllea pomifera, Erythrophleum africanum, Faurea saligna, Marquesia curatellifolia and Pericopsis (Afrormosia) angolensis. Characteristically the associated soils are free draining and often highly leached and acidic. Nevertheless, these woodlands provide habitat for hundreds of endemic plant species, although many are highly localised. The endemic trees include Allophylus didymadenius (Sapindaceae), Combretum gillettianum (Combretacea), Commiphora puguensis (Burseraceae), Diospyros mweroensis (Ebenaceae), Ficus fischeri (Moraceae), Magnistipula butayei (Chrysobalanaceae), Memecylon flavovirens (Melostomataceae), Ochna gambleoides (Ochnaceae), Oldfieldia dactylophylla (Euphorbiaceae), Psydrax richardsiae (Rubiaceae) and Terminalia gazensis (Combretaceae), but these are far out numbered by the endemic shrubs. In fact, these exceed 50 species and include Aeschynomene mossoensis (Fabaceae), Amphiasma redheadii (Rubiaceae), Anisophyllea bochmii (Rhizophoracea), Cadaba kirkii (Capparidaceae), Canthium burtii (Rubiaceae), Cissus trothae (Vitaceae), Cleistanthus polystachyus (Euphorbiaceae), Dichapetalum macrocarpum (Dichapetalaceae), Dissotis lanata (Melostomataceae), Embelia xylocarpa (Mrysinaceae), Grewia gilviflora (Tiliaceae), Hugonia gossweileri (Linaceae), Ochna mossambicense (Ochnaceae), Strophanthus welwitschii (Apocynaceae) and Vernonia suprafastigiata (Asteraceae). The trees and shrubs support a rich variety of climbers including endemic species like Adenia dolichosiphon (Passifloraceae), Bonamia mossambicensis (Convolvulaceae), Entada nudiflora (Fabaceae), and numerous epiphytes such as the endemic orchids Aerangis appendiculata, Bulbophyllum rugosibulbum, Polystachya zambesiaca and Tridactyla citrina (Orchidaceae).
Endemic ground layer species are also very numerous including grasses such as Melinis minutiflora, Sacciolepis transbarbata, Tristachya hubbardiana, Zonotriche inamoena Copyright © 2010 Peter Martin Rhind
(Poaceae), and a huge variety of forbs like Acalypha nyasica (Euphorbiaceae), Adenia erecta (Passifloraceae), Aeschynomene mossambicensis (Fabaceae), Aloa carnea (Aloaceae), Aristolochia hockii (Aristolochiaceae), Buchnera eylesii (Scrophulariaceae), Celosia vanderystii (Amaranthaceae), Chironia laxiflora (Gentianaceae), Cryphostemma rhodesiae (Vitaceae), Cynorkis hanningtonii (Orchidaceae), Dianthus angolensis (Caryophyllaceae), Diodia flavescens (Rubiaceae), Dorstenia buchananii (Moraceae), Hibiscus jacksonianus (Malvaceae), Lactuca zambeziaca (Asteraceae), Mechowia grandiflora (Amaranthaceae), Peucedanum angolense (Apiaceae) and Polygala stenopetala (Polygalaceae), and ferns such as Actiniopteris pauciloba (Adiantaceae).
In the dryer parts of the BioProvince Colophospermum mopane often becomes the dominant tree, and woodlands characterized by this species, and described locally as Mopane woodland, can be found as far a field as the Zambezi, Luangwa, Limpopo, Shashi and Sabi valleys, the Nanzhila and Machili basins of Zambia, the Makarikari and Okovango depressions in Botswana. Mopane itself even extends into the dryer parts of Angola where towards the limits of its range it can be found associated with the spectacular desert specialist Welwitschia bainesii. But even well within its range the woodlands dominated by this species show great variation in their species composition. In the Luangwa valley, for example, the most conspicuous associates are Acacia nigresens,
Angola Acacia erubescens, Balanites angolensis, Boscia microphylla, Catophractes alexandri, Combretum apiculatum, Commiphora angolensis, Grewia villosa, Rhizozum brevispinosum, Spirostachys africana, Terminalia prunioides and Ximenia caffra are some of the more characteristic species. Possibly because they are less extensive and more narrowly confined to the drier zones far fewer Zambezian endemic plants are found in mopane woodland compared with miombo woods. Nevertheless at least 50 endemic species been recorded. Some of the endemic or near endemic trees typically include
(Rubiaceae), Combretum obovatum (Combretaceae), Hippocratea buchananii (Hippocrateaceae), Rhigozum zambesiacum (Bignoniaceae), Strophanthus nicholsonii (Apocynaceae) and Teclea rogersii (Rutaceae). These woodlands also support far fewer climbers and epiphytes and possibly with the exception of the climbing herb
groups. The ground layer, on the other hand, is rich in endemic species including Crassula rhodesica (Crassulaceae), Eulophia dactylifera (Orchidaceae), Eureiandra eburnea (Cucurbitaceae), Gutenbergia polycephala (Asteraceae), Pterodiscus elliotii (Pedaliaceae), Sesuvium nyasicum (Aizoaceae), Spermacoce arvensis (Rubiaceae), and a variety of Jatropha species such as Jatropha botswanica (Euphorbiaceae). Zambezian Swamp and Riparian Forest In the wetter parts of the BioProvince swamp forest occurs in areas where water movement is sluggish. The most abundant trees here are fairly widespread species such as Mitragyna stipulosa, Syzygium owariense, Uapaca guineesis and Xylopia rubescens, which is also true for many of the undergrowth species like Aporrhiza nitida, Gacinia
endemic plants include trees such as Erythrococe welwitschiana and Uapaca lissopyrena (Euphorbiaceae), shrubs such as Alchornea yambuyaens and Phyllanthus retinervis
Copyright © 2010 Peter Martin Rhind
(Euphorbiaceae), Dissotis romiana (Melostomataceae) and Stapfiella zambesiense (Turneraceae), climbers such as Ipomoea pharbitiformis (Convolvulaceae), and ground layer herbs like Bothriocline ripensis (Asteraceae), Buchnera speciosa (Scrophulariaceae), and the orchids Habenaria orthocentron and Liparis molendinacea (Orchidaceae). The riparian forests often include Adina (Broenadia) microcephala, Khaga nyasica and Newtonia buchananii as the main tree species, while less frequent trees include the endemic Monopetalanthus trapnellii and Tessmannia burttii (Fabaceae).
These forests, which are usually characterized by the presence of Baikiaea plurijuga, are typically found in the dryer parts of the BioProvince, usually on sandy, free draining soils. The most extensive stands can be found in the Kalahari and in the southern part of the upper Zambezi basin. Other characteristic trees include Entandrophragma caudata and
such as Fagara trijuga (Rutaceae) Psychotria butayei (Rubiaceae), Rytigynia orbicularis (Rubiaceae), the suffrutex Ozoroa stenophylla (Anacardiaceae), climbers such as
include Erlangea remifolia (Asteraceae), Phyllanthus martinii and P.microdendron (Euphorbiaceae) and Vernonia rhodesiana (Asteraceae).
Chipya woodland is distinctive for the absence of typical miombo woodland species such as Brachystegia, Isoberline and Julbernandia. More characteristic are various fire resistant trees such as Afzelia quanzensis, Albizia autunesiana, Amblygonocarpus andongensis,
herbaceous layer, with three of the more common species Aframonum biauriculatum, Pteridium aquilinum and Smilax kraussiana usually absent from miombo woodland. However, chipya often consists of a complex mosaic representing different stages of succession, and in fact, usually owes it existence to former cultivation or fire. Some of the endemic plants include deciduous trees such as Terminalia erici-rosenii and T. trichopoda (Combretaceae), shrubs such as Combretum mweroense and Terminalia griffithsiana (Combretaceae), climbers such Combretum gossweileri (Combretaceae) and perennial ground layer herbs such as Acalypha fuscescens, Phyllanthus crassinervius, P. holostylus
and Vernonia subplumosa (Asteraceae) and Monostachya staelioides and Pentas purpurea (Rubiaceae). Zambezian Termite Mound Vegetation Termites not only pervade much of the soils of Africa they also contribute greatly to their formation, although they are absent at high altitudes and from some swampy or very sandy areas. Their termitaria are often conspicuous and where these are well established they often support a dense thicket with emergent trees. In fact, the flora of these sites can be incredibly rich supporting some 700 woody species, but because there is so much variation between mounds it is impossible to generalize in terms of community structure. Some of the more typical genera include Acacia, Albizia, Asparagus, Canthium, Cassia, Cassine, Combretum, Commiphora, Euclea, Ficus, Grewia, Popowia, Pterocarpus, Sansevieria, Ximenia and Ziziphus, while some of the more widespread termitaria species are Carissa edulis, Diospyros lycioides, Euphorbia candelabrum, Pappea capensis, Peltophorum africanum, Rhoicissus tridentata, Securinega virosa, Steganotaenia araliacea and Strychnos potatorum. There are also a relatively large number of endemic plants Copyright © 2010 Peter Martin Rhind
associated with termitaria including trees such as Cordia mukuensis, C. stuhlmannii (Boraginaceae), Diospyros mweroensis, D. truncatifolia (Ebenaceae), Grewia lepidopetala (Tiliaceae), Thamnus prinoides (Rhamnaceae) and Triplochiton zambesiacus (Sterculiaceae), shrubs such as Embelia upembensis (Mrysinaceae), Memecylon torrei (Melostomataceae), Nesaea heptomera, N. passerinoides (Lythraceae), Rhus milleri (Anacardiaceae), Trichilia capitata (Meliaceae) and Vepris termitaria (Rutaceae), climbers such as the evergreen Combretum gossweileri (Combretaceae), the suffrutex Lannea virgata (Anacardiaceae), and a large variety of herbaceous species including Heliotropium harareense (Boraginaceae), Lobelia quarreana (Lobeliaceae), Neuradopsis kechuanensis (Rosaceae), Pandiaka ramulosa (Amaranthaceae), Phyllanthus friesii (Euphorbiaceae), Plumbago amplexicaulis (Plumbaginaceae), Pyrenacantha kaurabassana (Icacinaceae), Savannosiphon euryphyllus (Iridaceae) and the grasses Leersia oncothrix and Sporobolus uniglumis (Poaceae).
The BioProvince includes various types of thicket, but the most extensive is known as Itigi thicket after the Tansananian village of Itigi. Comparable thickets occur in Zambia and Zimbabwe. It is largely composed of deciduous shrubs such as Baphia burttii, B.
that light is virtually excluded from the ground layer, which can be almost devoid of plant species, although the slender grass Panicum heterostachyum is often present. In southern and central Zambia there is a related thicket known as Pemba thicket named after the village of Pemba. Again most of the scrub species are deciduous and commonly include Acalypha chirindica, Aeschynomene trigonocarpa, Byrsocarpus orientalis, Canthium burttii, Cassipourea gossweileri, Haplocoelum foliolosum, Indigofera rhynchocarpa, Popowia obovata, Rytigynia umbellulata and Tarenna neurophylla. Emergent tree are rare and several, such as Brachystegia spiciformis, Combretum collinum and Lannea discolor, are heliophilous and do not easily regenerate in the shade of thicket. Their presence is likely to be related to the activities of large mammals and possibly natural fires. Deciduous thickets such as Itigi and Pemba provide habitat for a variety of endemic plants including the climber Combretum aureonitens (Combretaceae), the shrub Meiostemon tetrandrus (Combretaceae) and the small deciduous tree Vepris
valleys is dominated by Commiphora species such as C. pyracanthoides subsp. glandulosa, C. edulis, C. africana and C. mossambicensis together with Acacia mellifera, Stereospermum kunthianum and the endemic Schrebera trichoclada (Oleaceae), while other endemic shrubs include Aeschynomene trigonocarpa (Fabaceae).
At altitudes above about 1200m where drainage is sluggish up to 20% of plateau surfaces are covered in a dense grass mats known as dambos. The soils are usually acidic, and much of it is subject to seasonal flooding, but in the dry season it may dry out and become very compact. Their floristic composition shows considerable variation, but is by and large, composed of fine leaved grasses, together with a number of Cyperaceae and Xyridaceae. The most characteristic grass is Loudetia simplex, while other common grass species include Andropogon schirenss, Hyparrhenia bracteata, Miscanthus teretifolius, Monocymbium ceresiiforme, Themeda triandra and Trachypogon spicatus. Endemic grasses found here include Brachiaria clavipila, Digitaria bidactyla, D. complanata, D. hyalina, D. phaeotricha, many Eragrostis species such as E. acamptoclada, E. anacrantha, E. astreptoclada, E. aurorae, E. caniflora, E. castellaneana, E. dentifera, E. Copyright © 2010 Peter Martin Rhind
Sporobolus fibrosus (Poaceae). In the wetter areas there can be a great variety of Cyperaceae including Ascolepis anthemiflora, Bulbostylis cinnamomea, Cyperus esculentus, Fuirena pubescens, Kyllinga erecta, Mariscus deciduus, Pycreus aethiops, Scirpus microcephalus and Scleria bulbifera. Among the endemic forbs found here are a wide variety of orchids such as Centrostigma clavatum and C. papillosum, and species of Brachycorythis, Disa, Habenaria, Platycoryne and Satyrium, while endemics from other plant families include Acalypha clutioides (Euphorbiaceae), Aeschynomene mediocris (Fabaceae), Ageratinastrum palustre (Asteraceae), Anagallis elegantula (Primulaceae),
(Melostomataceae), Eugenia malagensis (Myrtaceae), Hydrolea brevistyla (Hydrophyllaceae), Hypoxis nyasica (Hypoxidaceae), Ipomoea fanshawei (Convolvulaceae), Kniphofia reynoldsii (Asphodelaceae), Mechowia redactifolia (Amaranthaceae), Nesaea spathulata (Lythraceae), Sebaea gracilis (Gentianaceae) and
The BioProvince includes extensive flood plain grasslands with some of the best examples in the Malagarasi and Rukwa valleys in Tanzania, the upper Zambezi, Kafue, and Chambeshi valleys and the Mweru Wantipa and Bangweulu basins in Zambia, and the Lake Chilwa basin in Malawi. The principal grass species vary according to the degree of wetness, with species such as Acroceros macrum, Echinochloa pyramidalis, Leersia
are the grasses Digitaria rukwae, Microchloa annua and Tristachya lualabaensis (Poaceae), several herbaceous species of the Asteraceae including Ethulia paucifructa,
and Phyllanthus zambicus (Euphorbiaceae) and the subshrub Kotschya longiloba (Fabaceae).
Confined to uplands such as the Nyika and Mafinga Hills both of these grassland types are composed of short and tufted grasses. The dominant species often include Exothecia abyssinica, Loudetia simplex, Monocymbium ceresiiforme and Trachypogon spicatus, while the many endemic grasses are Allaeochaete geniculata (Mt Mulanje), A. namuliensis, A. oreogena (Mt Mulanje), Eragrostis canescens, E. desolata, (Mt Chimanimani), E. fastigiata (Mt Mulanje), E. sylviae (Mt Mulanje), Panicum eickii, P. inaequilatum, P. lukwangulense and Rytidosperma davyi. These grasslands are also very rich in orchid species with some of the endemic species represented by Brownleea mulanjiensis (Mt Mulanje), Cynorkis brevicalcar (Mt Mulanje), Disa zombica, Habenaria xanthochlora, Herschelianthe longilabris, Holothrix tridactylites, Liparis rungweensis, Neobolusia ciliata, Polystachya lawrenceana, Roeperocharis wentzeliana, many species of Satyrium including S. buchananii, S. microcorys, S. monadenum, S. oliganthum, S. princeae, S. rhynchantoides and species of Schizochilus including S. calcaratus, S. lepidus, S. sulphureus. But these rich grasslands support many other endemic species with herbaceous examples including Ageratinastrum polyphyllum (Asteraceae), Aloa rhodesiana (Aloaceae), Clutia swynnertonii (Euphorbiaceae), Cynoglossum inyangense (Boraginaceae), Gladiolus zimbabweensis (Iridaceae), Impatiens schulziana (Nyika Plateau) (Balsaminaceae), Kniphofia reynoldsii (Asphodelaceae), Pentas lindenioides
Copyright © 2010 Peter Martin Rhind
(Rubiaceae), Phyllanthus tsetserrae (Euphorbiaceae), Swertia johnstonii (Gentianaceae), Trachyandra malosana (Asphodelaceae) and Walafrida swynnertonii (Scrophulariaceae).
Further information required.
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Goldblatt, P. 1978. An analysis of the flora of southern Africa: its characteristics, relationships, and origins. Annals of the Missouri Botanical Garden, 65: 369-436.
Lawton, R. M. 1978. A study of the dynamic ecology of Zambian vegetation. Journal of Ecology, 66: 175-198.
Malaisse, F. 1978. The Miombo ecosystem. In: Tropical forest ecosystems. Natural Resources Research Vol. XIV. UNESCO
Menaut, J. C. 1983. The Vegetation of the African Savannas. In: Ecosystems of the World 13 - Tropical Savannas. Ed. F. Bourliere. Elsevier Scientific Publishing Company.
O’Conner, T. G. 2005. Influence of land use on plant community composition and diversity in Highland Sourveld grassland in southern Drakensberg, South Africa. Journal of Applied Ecology, 42: 975-988.
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Roberts, B. R. 1968. The Orange Free State. In: Conservation of Vegetation in Africa south of the Sahara. Eds. I. Hedberg and O. Hedberg. Acta Phytogeographica Suecica, 54: 275-279.
White, F. 1976. The underground forest of Africa: a preliminary review. Gardens Bulletin (Singapore). 29:55-71.
White, F. 1978. The Indian Ocean Coastal Belt. In: Biogeography and Ecology of southern Africa. Ed. M. J. A. Werger. Dr W Junk Publishers. The Hague.
White, F. 1983. The Vegetation of Africa. UNESCO. Wild, H. & Fernandes, A. 1967. Flora Zambesiaca - (Supplement) Vegetation Map of the Flora Zambesiaca Area. M. O. Collins, Rhodesia.
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