CHAPTER TWO THE STUDY SITE Introduction The Nyika Plateau is situated in south central Africa between 10o15’-10o50’S and 33o35’34o05’E. It sits astride the Malawi/Zambia border to the north west of Lake Malawi. Most of the plateau is in Malawi with a small western section (about seventy square kilometres) (Dowsett-Lemaire 1985) in Zambia. Physical features The Nyika is a massif with an extensive high altitude plateau which covers about 2330 square kilometres (Meadows 1984; Happold & Happold 1989). The roughly oval plateau, which is oriented in a north-east direction, is about 80.5 kilometres long and 56.35 kilometres wide and tilts gently from 2440 metres high in the west to 2135 metres high in the east. Most of the plateau lies between 1800 m and 2606 m (Meadows & Linder 1993). A bevelled surface at 1,676 m and steep escarpments ring the plateau (Meadows 1984). The altitude from the lowest point of the massif (along the Ruwile River in the northeast) to the highest peak (Nganda) ranges from 582 m to 2606m (Willis et al. 2001). On the gently undulating plateau surface, ridges - whose gentle convex sides slope between ten to fifteen degrees- alternate with wide, deep and level depressions (Willis et al. 2001). The depressions, which are occasionally up to 1 kilometre wide and two hundred metres deep, have poorly drained marshy floors that are partially filled mostly with deposits of peat and a variety of other sediments (Meadows 1984; Willis et al. 2001). Towards the margins of the plateau, especially in the north and east, the valley slopes become steeper (Willis et al. 2001). Large and high outcrops (Nganda, 2,606m, Vitumbi, 2,527m and Kasaramba 2,460m) occasionally rise from the plateau surface (Willis et al. 2001). The main rivers draining the Nyika plateau include the North Rumphi, Chelinda (Rumphi), Runyina, and North Rukuru. These perennial rivers, which originate from broad grass-covered depressions (dambos) on the plateau, have cut wide and deep erosional valleys. There is only one natural lake on the plateau, Lake Kaulime (near Chelinda), which was formed by a landslide which blocked the outflow from one of the headwaters of the North Rukuru River (Willis et al. 2001). Geology The Nyika massif is a massive upfolded block of granite and granitic gneiss formed by the intrusion of granite and younger dolerite into sediments of the Malinga series (Meadows 1984; Meadows & Linder 1993). This structure forms the western margin of the East African Rift Valley system (Meadows 1984). Three main formations of rocks constitute the high plateau area - the Cordierite Gneisses in the eastern part, the Chambo Gneisses in the north, and the large intrusive Nyika Granite (Meadows 1984). All three formations are intermediate to acidic in character and have relatively similar mineralogy (Meadows 1984). There is, thus, overall geological uniformity in the Nyika Plateau in relation to soil formation and vegetation (Meadows 1984). Soils The soils are rather poor and tend to be acidic. Climate The mean annual temperatures in the Nyika Plateau are of the order of 13-15oC with a low annual average of frost (one night in May, two in June, three in July and one in August) at 2300 metres above sea level (Dowsett-Lemaire 1989). Temperatures range from below 0°C in winter (June/July) to over 21°C in summer. The warmest months of the year are October and November and these mark the start of the single rainy season, which lasts from November to April (Dowsett-Lemaire 1989). The rains are followed by spells of mist, drizzle and sporadic showers in the winter months of May to mid-August (Dowsett-Lemaire 1989). The mean annual rainfall varies from 1000-1200 millimetres on the central plateau (2250-2500 m alt.) to around 1700mm on the top of the eastern escarpment (Dowsett-Lemaire 1989). The Southwest Nyika, though well forested, is exceptional in being totally dry for the best part of six months between May and October (Dowsett-Lemaire 1985). The areas of highest rainfall (with annual means above 1500 mm) are on the eastern, and to a lesser degree, western sides of the Nyika (Dowsett-Lemaire 1988). Much of the high plateau above 2200 m experiences a low rainfall usually averaging 1000 to 1200 mm per annum, with even lower figures in the north, in the shadow of the high peaks of Nganda and Domwe (Dowsett-Lemaire 1988). The days are long and the sun high, but the climate is temperate (Lemon 1968). The average amount of rainfall over much of the plateau is 1140 +/- 150 mm, of which about 90% falls from December through April (Lemon 1968). This leaves a dry period of about 6-7 months, although soil moisture storage is very good and streams run all year (Lemon 1968). Direct and diffuse radiation is approximately 450 cal/cm2 per day comparable with northern England and the extreme northeastern United States (Lemon 1968). The seasonal distribution and abundance of rainfall can vary greatly from year to year (Dowsett-Lemaire 1988). Historical background The oldest dated records of human occupation of the Nyika Plateau are placed at around 3500 BP (Meadows & Linder 1993). A European missionary, Reverend James Henderson, who traveled through the Nyika Plateau area between 1895 and 1899 found it thinly peopled by members of the Phoka (Anon 1900), a subgroup of the Tumbuka (van der Merwe & Avery 1987). The Phoka were settled on the plateau, the steep escarpment slopes and the foothills on the eastern and southern sides of the mountain massif (van der Merwe & Avery 1987). They however never permanently inhabited the area above 2000 metres (Dowsett-Lemaire 1985). The Phoka, whose scattered villages Reverend Henderson found “hardly worth counting as occupations”, practised very little cropping and kept a small number of goats and sheep (Anon 1900). Iron smelting, which ceased in the 1930s, was an important economic activity that had been going on for 2000 years (van der Merwe & Avery 1987). In 1902 a scientist, John McClounie, made the earliest recommendation for the conservation of the Nyika Plateau (Briggs 1998). In his report McClounie recommended that the Nyika Plateau be placed under protection and developed as a sanatorium for white settlers due to its temperate climate and the total absence of malaria-carrying mosquitoes (Briggs 1998). However it was not until 1948 that official action began to be taken which was in line with part of McClounie’s recommendation. In that year a relic patch of Juniperus procera forest (the most southerly stand of this tree in Africa) was proclaimed a forest reserve (Briggs 1998). Later on, in 1951, the entire plateau was declared a no-hunting zone (Briggs 1998). Then in 1965, shortly after Malawian independence, the Nyika Plateau was gazetted as a national park (Briggs 1998). Finally in 1978 the Nyika National Park was expanded from nine hundred and forty square kilometres to three thousand one hundred and thirty four square kilometres, increasing its area threefold (Willis et al. 2001). The park now included the plateau surface, all the escarpments and most of the northeast and south hill zones (Briggs 1998; Willis et al. 2001). This extension was intended to enable the Malawian Government to execute more efficient control over the Nyika’s large network of waterways, inhibit erosion, and reduce poaching. It also involved the destruction of some ten thousand Phoka dwellings and the removal of their owners to the edges of the national park (van der Merwe & Avery 1987). The 1975/76 Master Plan proposed that the Nyika National Park be zoned into five landuse classes developed by the Canadian National Parks Service: Class I Special Areas; II Natural Environment Areas; III Lower Category Natural Environment Areas; IV General Outdoor Recreation Area; and V Intensive Use Areas. This proposal has not yet been implemented. Although there is a management plan, staff and resources are below that required to implement it. Although burning is used as a management tool, the greatest threat to the vegetation is wildfire originating in and outside the park. Protection of the remaining forest patches from these annual burns is a critical problem. There is poaching, especially in the dry season. The present policy is to get rid of tenacious alien elements introduced when the Forest Department established a number of trial plots of exotic conifers and Eucalyptus on various grassy ridges before the Nyika Plateau was gazetted as a national park in 1964 (Dowsett-Lemaire 1988). The only maintained plot is a 1200 ha forest of Pinus patula surrounding the tourist camp at Chilinda (2300m) (Dowsett-Lemaire 1988). There is a permanent wildlife research officer and a general monitoring programme. An office with minimal equipment, reference books and specimens was reported in 1977, but no recent information is available. A research laboratory was planned at Chilinda. IUCN Management Category II (National Park) Biogeographical Province 3.20.12 (Central African Highlands) Vegetation The Nyika Plateau has the largest montane complex in south central Africa (Willis et al. 2001). The montane complex, which occupies an area of some 1 800 km2, is generally restricted to above the 1800 m contour (Dowsett-Lemaire 1985; Willis et al. 2001). This contour generally marks the zone of transition between the surrounding miombo woodlands - characterised by the dominance of trees in the genera Brachystegia, Isoberlinia, and Julbernardia- which occupy the lower lying slopes and plains, and the forests and grasslands of the higher montane ecoregion (Dowsett-Lemaire 1985; Willis et al. 2001). Grasslands On the Nyika Plateau the leading dominant species are sturdy tufted grasses, commonly referred to as “short grasses” though often 0.5-1.5 m tall (Lemon 1968). Between 2200 and 2500m the central plateau (about 60% of the montane area) consists of rolling Loudetia-Andropogon grassland dotted about with small patches of low forest accounting for less than 3% of the area (Dowsett-Lemaire 1988). Montane grasslands are mostly on gentle slopes above streams and swamps (Happold & Happold 1989). Ninety percent of the plateau over 1,800m is covered by short open grassland dominated by Loudetia simplex, red oat grass Themeda triandra and Exotheca abyssinica (Lemon 1968). The vegetation is essentially Loudentia simplex, Trachypogon spicatus, Exotheca abyssinica and Helichrysum spp (Happold & Happold 1989). Loudetia simplex, Eragrostis capensis, Monocymbium cerisiiforme, Imperata cylindrica, Alloteropsis semilata, Russet grass Loudetia simplex and unicorn grass Exotheca abyssinica are widespread and dominant while Shire bluestem Andropogon schirensis, grey beard grass Trachypogon spicatu, and oat grass Danthonia spp are often important in patches (Lemon 1968). Loudentia simplex is dominant on sands with Eragrostis racemosa, F. capensis, Elyonurus argenthus, Andropogon schirensis, Digitaria apiculata and D. monodactyla as common associates (Lemon 1968). Earlier in the season, especially with the aid of fire, a vernal aspect may appear with sour grass Elyonurus argentens silver spike Imperata cylindrica and Rendlia altera becoming common (Lemon 1968). Paspalum commersoni and Setaria sphacelota occur as ordinary dry land species in areas of high rainfall conditions, whereas in areas of about 1016 mm of rainfall they are confined to vleis, stream banks, and other moist localities (Lemon 1968). Themeda trianda predominates on fertile soils (Lemon 1968) while on poorer soils Monocymbium cerisiiforme and Schimper’s fescue Festuca schimperiana occur in quantity (Lemon 1968). As the grassland community meets other vegetation types, there are shifts in dominants (Lemon 1968). For instance, the red oat grass, Themeda trianda and the coloured hood grass Hyperrhenia cymbaria are predominant in grassland areas in contact with spreading forest margins (Lemon 1968). Herbaceous vegetation There are myriads of flowering herbs, some blooming in the rainy season, some in the drier parts of the year (Lemon 1968). The streams and margins of the swamps are often bordered by the shrub Phillipia benquelensis (Happold & Happold 1989). The dambos are occupied by a rich moist-habitat herbaceous flora dominated by species of the Cyperaceae family, mostly Carex and Cyperus (Willis et al. 2001). At the edges of moist drainage-ways bracken fern (Pteridium aquilinum) and heaths (Blaeria patula, B. kewensis) and other low shrubs are found (Lemon 1968). Pteridium aquilinum is also common on disturbed soil (Lemon 1968) Examples of other shrubs found on the plateau include Lastophon kraussianus and two low proteas (Protea heckmanniana and P. madiensis) (Lemon 1968). Smithia thymodora and Psoralea foliosa are significant in areas under close grazing (Lemon 1968). Afromontane forests The forests on the Nyika have been by divided by Dowsett-Lemaire (1988) on the basis of floristic composition, structure and altitude into two types viz. a vi submontane rain forest and montane forest sensu stricto. In her scheme submontane forests are those that have a higher canopy, more complex structure (e.g. emergent buttressed trees, large number of woody climbers) and occur at lower altitudes (Dowsett-Lemaire 1988). The canopy in these submontane forests is mostly continuous and the ground cover is often no more than the odd herb or fern in a carpet of dead leaves (Dowsett-Lemaire 1988). The limit between submontane and montane forests lies at about 2300 m on the eastern escarpment and 2250 m on the western side (Dowsett-Lemaire 1988). The most extensive block of Afromontane forest on the Nyika massif is found on the very steep slopes of the eastern escarpment (Dowsett-Lemaire 1988). This block, which extends for about 28 kilometres in a SW-NE direction, covers an area of several square kilometres (Dowsett-Lemaire 1988). Another important block of forest lies north of Mwenembe, on the north side of the North Rumphi stream, and measures about 6 square kilometres (Dowsett-Lemaire 1988). The lower limit of these forests, usually between 1700 and 1900 metres recedes each year through recurrent dry season fires (DowsettLemaire 1988). Numerous small and large patches of tall forest at 1950 -2200 metres cover the southern and southwestern slopes (Dowsett-Lemaire 1988). The lowest fragments of these forests are found at about 1925 m (Dowsett-Lemaire 1988). The edges of Afromontane forest patches and blocks are usually sharply cut with little secondary growth fringing them above 2250 m (Dowsett-Lemaire 1988). However with decreasing altitude the secondary growth form larger patches around the forests until at 2000-2100 m it covers vast areas of many hectares (Dowsett-Lemaire 1988). Brachystegia woodland ascends to the top of the escarpment at 2050 m on the drier western slopes (Dowsett-Lemaire 1988). Afromontane forest is limited to very narrow strips of riparian vegetation, especially along the North Rukuru river (Dowsett-Lemaire 1988). In the north the plateau drops into dry broken wooded country from 2300 to 16001700 m (Dowsett-Lemaire 1988). The Juniper forest (10o45’S, 33o55’E) which is about 10 hectares and is found on the slopes above the Uyaghaya stream is the southernmost limit of the geographic range of the Juniper Juniper excelsa (Happold & Happold 1989). The Juniper forest is characterised by large, tall trees, decaying logs deep leaf litter, bryophytes and climbers (Happold & Happold 1989). It is cooler and shadier than the broad-leafed montane forest (Happold & Happold 1989). Fauna The range of vegetation on the plateau attracts a great diversity of animals and birdlife. There are also several sub-species of reptiles, amphibians and butterflies endemic to the area. There are over 400 recorded species of bird on the Nyika Plateau. The birds in both the montane forest patches, and the surrounding grassland, have a distinctly East African feel, this being the southern limit of distribution for many of them. More details of the birds are given in Dowsett-Lemaire (1983). Mammalian species recorded in the park include leopard Panthera pardus, lion P. leo, spotted hyena Crocuta crocuta, side-striped jackal Canis adustus, samango monkey Cercopithecus albogularis, vervet monkey C. aethiops, zebra Equus burchelli, warthog Phacochoerus aethiopicus, reedbuck Redunca arundinum, bushbuck Tragelaphus scriptus, greater kudu T. strepsiceros, eland Taurotragus oryx, common duiker Sylvicapra grimmia, roan antelope Hippotragus equinus, red duiker Cephalophus natalensis harveyi, Lichtenstein's hartebeest Alcelaphus lichtensteini, klipspringer Oreotragus oreotragus, and puku Kobus vardoni (only vagrants). Fewer than 50 elephants Loxodonta africana have been recorded in the park and their numbers are decreasing. Subsistence poaching from neighbouring areas threatens several of the park’s less common mammal species, and while animal populations in the immediate vicinity of Chilinda are stable, possibly even growing. However fewer and fewer large mammals are recorded with distance from this one small area (Briggs 1998). The upper South Rukuru contains several fish such as Barbus and Clarias spp., which do not occur elsewhere in Lake Malawi rivers. Four major streams (Chilinda, Rumphi, Runyina and North Rukuru) and three dams near Chelinda have been stocked with rainbow trout and fishing is permitted under licence from 1 September to 30 April. References Anon. 1900. Anthropological reviews and miscellanea. The Journal of the Anthropological Institute of Great Britain and Ireland 30: 20-21. Briggs, P. 1998. A natural high. Travel Africa magazine. Edition 5. Dowsett-Lemaire, F. 1983. Ecological and territorial requirements of montane forest birds on the Nyika plateau, south central Africa. Gerfau, 73: 345-378. Dowsett-Lemaire, F. 1985. The forest vegetation of the Nyika Plateau (Malawi-Zambia): ecological and phenological studies. Bull. Nat. Plantentuin Belg 55: 301-392 Dowsett-Lemaire, F. 1989. The flora and phytogeography of the evergreen forests of Malawi I: Afromontane and mid-altitude forests. Bull. Nat. Plantentuin Belg 59: 3-131 Happold, D.C.D. & Happold, M. 1989. Biogeography of montane small mammals in Malawi, Central Africa. Journal of Biogeography 16: 253-367. Lemon, P.C. 1968. Effects of fire on an African plateau grassland. Ecology 49: 316-322. Meadows, M.E. & Linder, H.P. 1993. A palaeoecological perspective on the origins of Afromontane grasslands. Journal of Biogeography 20 (4), 345-355. Meadows, M.E. 1984. Late Quaternary vegetation history of the Nyika Plateau, Malawi. Journal of Biogeography 11(3): 209-222. Van der Merwe, N.J. & Avery, D.H. 1987. Science and medicine in African technology: Traditional iron smelting in Malawi. Journal of the International African Institute 57 (2): 143-172. Willis, C.K., Burrows, J.E., Fish, L., Phiri, P.S.M., Chikuni, A.C. & Golding, J. 2001. Developing a greater understanding of the flora of the Nyika. Syst. Geogr. 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