Location and General Description
This ecoregion is disjunct in distribution and consists of four main parts, separated at least partially by the drainage systems of Zimbabwe and Zambia. The largest section covers most of Zimbabwe, and spills over into Mozambique on the eastern side of the Chimanimani Mountain Range. Zambezian Mopane Woodland surrounds most of this area and separates this block from the second largest section of the Southern Miombo Woodland ecoregion. North of the Zambezi Valley, this portion extends over the southern third of Zambia, as well as into the western parts of Malawi and northern Tete province in Mozambique. To the north and northwest of this ecoregion, the vegetation mostly gives way to Central Zambezian Miombo Woodland. The remaining smaller segments are located in southern Mozambique, narrowly separated by the Rio Save and bordering White’s (1983) Zanzibar-Inhambane regional mosaic to the east. To the west, mopane and undifferentiated woodland of the Zambezian Mopane Woodland ecoregion predominates.
Most of the ecoregion is found on the Central African Plateau at elevations ranging between 1,000 and 1,500 m. Although the area is characterized by flat or undulating plains, intrusive granites and gneisses dominate geologically, and frequently rise up above the woodland as rounded hills (also known as dwalas) or inselbergs. Numerous grassy wetlands are interspersed along drainage lines in vleis or dambos (Barnes 1998). Highly weathered, acidic, and nutrient-poor soils, mainly alfisols and some oxisols in wetter locations, predominate and are more than 3 m deep in places. Shallow stony soils are common along the escarpment and around inselbergs. Soils are generally well-drained. To the west, the ecoregion extends marginally onto aeolian Kalahari sands. The sections of the ecoregion in Mozambique are found at much lower elevations, from 200 to 800 m, and are mostly on sedimentary Karoo Sandstones (Barnes 1998).
The ecoregion generally experiences a tropical savanna climate with three distinct seasons: a hot dry season from mid-August through October; a hot wet season from November through March; and a warm dry season from April through early August. Mean maximum temperatures range between 18°C and 27°C, but are typically around 24°C. The ecoregion experiences mean minimum temperatures between 9°C and 15°C, and is virtually frost-free. Temperatures are considerably higher in the lowland areas of the ecoregion. Rainfall is highly seasonal, with a marked winter drought usually lasting from 4 to 7 months (Cole 1986). The mean annual rainfall is around 600 to 800 mm in the main part of the ecoregion in Zimbabwe and increases to about 1,000 mm in the lower-elevation portion in Mozambique.
Floristically, this ecoregion forms part of a wide belt of miombo woodland that stretches from Angola in the west to Tanzania in the east. This miombo belt is virtually synonymous with the Zambezian Phytochorion, the largest of White’s (1983) Regional Centers of Endemism within Africa. Miombo plant communities are dominated by trees belonging to the family Caesalpiniaceae, and characterized by Brachystegia and Julbernardia species.
This ecoregion, mapped by White (1983) as drier Zambezian miombo, is floristically impoverished, although areas of serpentine soils in Zimbabwe provide localized sites of speciation and endemism (Frost 1996). B. spiciformis and J. globiflora predominate. Other common tree species include Uapaca kirkiana, B. boehmii, Monotes glaber, Faurea saligna, F. speciosa, Combretum molle, Albizia antunesiana, Strychnos spinosa, S. cocculoides, Flacourtia indica, and Vangueria infausta. Grass cover is usually sparse.
This ecoregion can be found in association with a number of other vegetation communities. Where drainage is poor, acacia savannas or grassland may become locally dominant (Werger 1978). Other associated vegetation includes dry deciduous forest and thicket, as well as deciduous riparian vegetation (White 1983).
The human population of this ecoregion is fairly high, and the area includes the cities of Harare and Lusaka (the capitals of Zimbabwe and Zambia, respectively). While a large number of people live in urban centers, an estimated 73 percent of the Zimbabwean population live in rural areas and rely on subsistence farming as a livelihood (Barnes 1998). Population densities are between 50 and 200 persons per km2 for most of the area, falling to fewer than 50 persons to the west and in Mozambique to perhaps fewer than 20 persons per km2, although reliable data are not readily available.
The overall faunal diversity of this ecoregion is fairly high, as many of its species overlap with surrounding miombo and savanna ecoregions. Annual droughts can last up to seven months and fires are frequent. As a result, many species are at least seasonally dependent on non-miombo sites within or adjacent to the ecoregion to provide food, water or shelter. These non-miombo refuges also provide a greater variety of habitats, resulting in higher richness in ecotonal areas within the ecoregion, such as near inselbergs or rivers, than in areas of uniform miombo woodland (Rodgers et al. 1996).
While miombo woodland in general provides important habitat for many large animals, the ecoregion does not support high densities of mammals per unit area, probably due to the seasonally arid conditions and poor soil, and hence forage quality. Several threatened animals occur in this ecoregion, including the critically endangered black rhino (Diceros bicornis) and the endangered elephant (Loxodonta africana) (Hilton-Taylor 2000). Although the ecoregion does not support these globally endangered animals in very large numbers, it is still important habitat because both species are known to have potentially large home ranges (Kingdon 1997) and utilize miombo habitat. Of the 50,000 to 60,000 elephants thought to occur in Zimbabwe, roughly 27,000 animals are concentrated in mopane woodland that borders this ecoregion (Stuart et al. 1990). Until a few years ago these areas supported the largest population of black rhino in Africa (about 2,200) (Stuart et al. 1990). White rhinos (Ceratotherium simum) are also known to inhabit the region and are listed as lower risk by the IUCN Red List (Hilton-Taylor 2000).
The overall paucity of large animals in this ecoregion favors the roan antelope (Hippotragus equinus), one of the mammals largely restricted to this habitat type, as it prefers habitats that have few competitors or carnivores (Kingdon 1997). Other ungulates typical of this ecoregion include sable (H. niger), Lichtenstein’s hartebeest (Signoceros lichtensteinii), southern reedbuck (Redunca arundium), greater kudu (Tragelaphus strepsiceros), eland (Taurotragus oryx), and buffalo (Synerus caffer) (East 1998). Tsessebe (Damaliscus lunatus) are also known to occur in the area (Stuart and Stuart 1992).
Most of the ungulates characteristic of miombo woodland are specialized grazers that selectively feed on nutrient-rich, actively growing grass shoots (Frost 1996). This means that they require large foraging areas, as they often have to move seasonally through the landscape in search of suitable fodder. For example, sable antelope remain within miombo woodland for much of the rainy season (October to May), but move out during the dry season (Kingdon 1997). Many of these ungulates also rely on ecotones or non-miombo habitat within the ecoregion. For example, Lichtenstein’s hartebeest prefers the ecotone between miombo and dambos (Smithers and Wilson 1979), while the southern reedbuck is most often found in rank grass valleys and glades within miombo woodland (Kingdon 1979).
Large carnivores characteristic of the region include lion (Panthera leo), leopard (P. pardus), cheetah (Acinonyx jubatus), spotted hyena (Crocuta crocuta), and the endangered African wild dog (Lycaon pictus). Smaller predators include caracal (Felica caracal), side-striped jackal (Canis adustus) as well as Selous’s mongoose (Paracynictis selousi), which is a fairly range-restricted species.
Of the nearly 500 bird species found in the area, none are strictly endemic. However, six species are either largely confined to the ecoregion or have extremely small distribution ranges. Lilian’s lovebird (Agapornis lilianae), mostly inhabits mopane woodland in the Zambezi Valley, but seasonally wanders into more mixed woodland on alluvial terraces (Harrison et al. 1997). The boulder chat (Pinarornis plumosus) is found in well-wooded terrain with large boulders. Stierling’s woodpecker (Dendropicos stierlingi) is confined to two small areas of southern Malawi with the remainder of the population restricted to the Eastern Miombo Woodland ecoregion, while Chaplin’s barbet (Lybius chaplini), endemic to south-central Zambia, is a locally common resident of miombo woodland. The latter species is considered lower risk/near threatened by BirdLife International (2000). The pink-throated twinspot (Hypargos margaitatus) and the lemon-breasted canary (Serinus citrinipectus) have restricted ranges and utilize miombo woodland, although their main ranges fall outside this ecoregion. Three globally threatened species are also found in this ecoregion, including two vulnerable species, the Cape vulture (Gyps coprotheres) and the lesser kestrel (Falco naumanni), as well as the lower risk Taita falcon (Falco fasciinucha), which is threatened by pesticide use in northern Zimbabwe (Barnes 1998, BirdLife International 2000).
Reptiles are the only animal group with high levels of endemism in this ecoregion, with 30 species of snakes and lizards predominantly or exclusively found in south miombo. However only four species are strict endemics: regal girdled lizard (Cordylus regius), dwarf wolf snake (Cryptolycus nanus), ocellated flat lizard (Platysaurus ocellatus), and Platysaurus oshaughnessyi.
Historically, miombo vegetation was relatively underpopulated, partially due to poor soils, which made it unsuitable for cultivation (Chenje and Johnson 1994). The great rinderpest epidemic of the late nineteenth century further contributed to the depopulation of both people and livestock in the area. This allowed thick woodland vegetation to grow, which provided ideal habitat for the proliferation of the tsetse fly (an insect that causes livestock and human sleeping sickness), (Misana et al. 1996). Since the tsetse fly does not affect wildlife, and the area is sparsely populated, miombo provides excellent habitat for game parks. Dry savannas (which include miombo habitat) are today one of the most extensively protected vegetation types in southern Africa (Chenje and Johnson 1994). However, in recent years miombo has been facing increasing pressure due to human population expansion and activities. Aside from protected areas, there is little undisturbed miombo left (Chenje and Johnson 1994).
Fortunately, Zimbabwe, which contains the largest contiguous section of the ecoregion, is internationally renowned for its well-organized, effective and enlightened conservation effort (Stuart et al. 1990). It is also responsible for having spearheaded community-based conservation in southern Africa through the CAMPFIRE Program. About 13 percent of Zimbabwe’s total land area is protected (Chenje and Johnson 1994). Zambia’s protected areas cover 32 percent of the country, although most of these areas fall into the Central Miombo Woodland ecoregion. These areas have suffered from insufficient management in the past (Stuart et al. 1990).
Although there are only three official Zambian protected areas that fall into the ecoregion, Game Management Areas (GMAs) cover most of the remaining area of in the Zambian portion of this ecoregion. North Luangwa National Park, bounded by the Muchinga Escarpment in the west and the Luangwa River in the east, is mostly covered by miombo vegetation, with some open grassland on the floodplain. Lukusuzi National Park is found in the eastern watershed area of the Luangwa River. Almost half the park consists of plateau where miombo is dominant, although grassland is also found on the plateau and along rivers. Both parks have an abundance of wildlife representative of the ecoregion. The expansive Lower Zambezi National Park lies on the northern bank of the Zambezi River. Miombo vegetation covers the slopes while mopane and acacia dominate in the valley. A wide variety of game occurs in the area, although poaching has drastically reduced black rhino and elephant populations (Stuart and Stuart 1992).
The miombo regions of Zimbabwe support a large number of small protected areas, many of which are found in rugged wilderness terrain. These parks and reserves include Chizarira National Park, Chirisa Safari Area, Matusadona National Park, and Mavuradonha Safari Area, which are all found in the north regions of the country. Other smaller parks such as Nyanga National Park, Mazowe Botanical Reserve, Sebakwe, Robert McLlwaine, Lake Kyle, and Ngezi Recreational Parks are much more accessible, as they are close to main transport routes or major towns, but do not harbor significant populations of charismatic large mammals. Private wildlife conservancies are becoming more numerous in Zimbabwe, offering consumptive and non-consumptive safaris.
Mozambique, having suffered serious upheavals through years of civil war, does not presently have any effectively managed areas. Almost all wildlife was wiped out over the years for meat and to finance the war. Some management plans and efforts are, however, beginning to be reapplied to Gorongosa National Park, a protected area that falls into the ecoregion.
Types and Severity of Threats
A large proportion of this miombo ecoregion has been completely transformed. Outside protected areas, some of the most immediate threats result from expanding cultivation, commercial logging, overgrazing, rapid population growth, and too-frequent fires (Chenje and Johnson 1994). Although habitat is fairly well conserved in protected areas, even national parks are affected by people who increasingly encroach onto protected land to search for fuel, wood, or new grazing or farming areas (Misana et al.1996). Poaching, especially of black rhinos and elephants, is a continuing problem and has resulted in severe losses of animals, despite extensive protection efforts (Misana et al. 1996). According to government figures, Zimbabwe may have lost as much as 80 percent of its black rhino population due to poaching in 1992 alone (Chenje and Johnson 1994). The current political and economic situation in Zimbabwe poses a threat to the extensive system of protected areas, and land invasions threaten the private wildlife conservancies.
The large-scale cultivation of cash crops, such as maize, wheat, and especially tobacco, has seen a huge conversion of miombo into agricultural land. In the case of tobacco, growing this export crop has led to large losses of woodland, both for land and fuelwood (Moyo et al 1993). These losses are increased by a need for fresh land each year to avoid risk of root-knot nematodes, as well as for the curing of tobacco, which is presently often carried out using charcoal (Misana et al. 1996). Several wildlife species are perceived as pests by farmers and are frequently eliminated on private lands. For example, livestock farmers have eradicated the African wild dog from large areas, while the aardvark is routinely exterminated on agricultural land (Kingdon 1997). Leopards are normally not tolerated by livestock farmers as well, although that situation may change where trophy hunts are allowed.
Expanding rural populations and the subsistence use of resources place substantial strain on the ecoregion. More than 80 percent of the people living in miombo depend on fuelwood for cooking, heat, and light, and grazing pressures of communal livestock populations are considerable, especially in Zimbabwe (Misana et al. 1996). Hunting for bushmeat was once conducted primarily for subsistence and cultural traditions. Now, the trade is becoming commercialized and urbanized, often catering to the urban market (TRAFFIC 2000). Other species are used for traditional medicine. For example, the scales of the ground pangolin (Manis temminckii) are used as love charms (Kingdon 1997).
Justification of Ecoregion Delineation
This ecoregion is comprised of White’s (1983) ‘drier Zambezian miombo woodland’ to the southwest of Lake Malawi, and includes several other areas east of the Zimbabwe Highlands, west of Lake Malawi, and southeast of Lake Kariba due to similar vegetation compositions.
This ecoregion is part of larger complex of Caesalpinoid woodland ecoregions that support wet and dry miombo, mopane, thicket, dry forests, Baikiaea woodland, and flooded grassland habitats, among others. The dominance of Caesalpinoid trees is a defining feature of this bioregion (i.e., a complex of biogeographically related ecoregions). Major habitat types (e.g., mopane and miombo) and the geographic separation of populations of large mammals are used to discriminate ecoregions within this larger region. All of these ecoregions contain habitats that differ from their assigned biome or defining habitat type. For example, patches of dry forest occur within larger landscapes of miombo woodlands in several areas. More detailed biogeographic analyses should map the less dominant habitat types that occur within the larger ecoregions.
Barnes, K.N., editor. 1998. Important Bird Areas of Southern Africa. BirdLife South Africa, Johannesburg.
BirdLife International. 2000. Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International.
Cole, M. 1986. The savannas: biogeography and geobotany. Academic Press, London.
Chenje, M, and P. Johnson., editors. 1994. State of the Environment in Southern Africa. Southern African Research and Documentation Centre, Harare, Zimbabwe.
East, R. 1998. African Antelope Database 1998. IUCN/SSC Antelope Specialist Group. IUCN. Gland.
Frost, P. 1996. The ecology of miombo woodlands. B.Campbell, editors. The Miombo in Transition: Woodlands and Welfare in Africa. Centre for International Forestry Research, Malaysia. pp 11–57.
Harrison, J.A., D.G. Allan, L.G. Underhill, S.M. Herreman, A.J. Tree, V. Parker, and C.J. Brown, editors. 1997. The Atlas of Southern African Birds. 2 Vols. BirdLife South Africa, Johannesburg.
Hilton-Taylor, C. 2000. The 2000 IUCN red list of threatened species. IUCN, Gland, Switzerland and Cambridge, UK.
Kindgon, J. 1997. The Kingdon Field Guide to African Mammals. Academic Press, San Diego.
Misana, S., C. Mung’ong’o, and B. Mukamuri. 1996. Miombo Woodlands in the wider context: macro-economic and inter-sectoral influences. Pages 73-99 in B. Campbell, editor. The Miombo in Transition: Woodlands and Welfare in Africa. Centre for International Forestry Research, Malaysia.
Moyo, S., P. O’Keefe, and M. Sill. 1993. The Southern African Environment. The ETC Foundation Earthscan Publication Limited. London.
Rodgers, A., J. Salehe, and G. Howard. 1996. The biodiversity of miombo woodlands. Page 12 in B. Campbell, editor. The Miombo in Transition: Woodlands and Welfare in Africa. Centre for International Forestry Research, Malaysia.
Smithers, R.H.N. and V.J. Wilson. 1979. Check list and atlas of the mammals of Zimbabwe Rhodesia. Museum Memoir 9, National Museum and Monuments of Zimbabwe Rhodesia, Salisbury.
Stuart, C. and T. Stuart. 1992. Guide to Southern African Game and Nature Reserves. Struik, Cape Town.
Stuart, S.N., R.J. Adams, and M. Jenkins. 1990. Biodiversity in Sub-Saharan Africa and its Islands. Conservation, Management and Sustainable Use. Occasional Papers of the IUCN Species Survival Commission No. 6. IUCN, Gland, Switzerland.
TRAFFIC. 2000. Food for thought: the utilization of wild meat in eastern and southern Africa. Retrieved (2001) from: http://www.traffic.org/bushmeat/
Werger, M.J.A. 1978. Biogeography and Ecology of Southern Africa. Junk, The Hague.
White, F. 1983. The vegetation of Africa, a descriptive memoir to accompany the UNESCO/AETFAT/UNSO Vegetation Map of Africa (3 Plates, Northwestern Africa, Northeastern Africa, and Southern Africa, 1:5,000,000. UNESCO. Paris.
Prepared by: Karen Goldberg
Reviewed by: In progress