The vegetation of Tshanini Game Reserve and a comparison with equivalent units in the Tembe Elephant Park in Maputaland , South Africa

An analysis of the plant communities of the to be proclaimed Tshanini Game Reserve and their relation with selected similar plant communities of Tembe Elephant Park are presented. The study area lies 6 km due south of Tembe Elephant Park within the Maputaland Centre of Plant Endemism, which is part of the Maputaland-Pondoland region recognised by the IUCN as a centre of Plant Diversity. A Braun-Blanquet classification on 51 random sample plots revealed eight distinct, mainly woodland plant associations. Vegetation distribution follows the same patterns as described in Tembe Elephant Park. Plant communities and subcommunities are mapped, described and compared to similar plant communities in Tembe Elephant Park to detect differences between protected and unprotected areas. Results from the qualitative comparison showed >50 % similarity between equivalent units and results from the quantitative comparison showed >25 % to 50 % similarity between equivalent units. Mueller-Dombois and Ellenberg (1974) regard 25 % as the lower threshold value to indicate similar associations. The observed differences may relate to animal and human utilisation.


Introduction
The Tembe Elephant Park was proclaimed in 1983 after negotiations between the then KwaZulu Bureau of Natural Resources and the Tembe Tribal Authority in consultation with the local communities of northern Maputaland, KwaZulu-Natal, South Africa.The park boundaries were subsequently fenced and animal numbers started to increase.The fence has kept the utilisation of renewable natural resources by the local communities at bay for the past 19 years.In this period, the vegetation of the park has been utilised only by the indigenous fauna, but it has been affected by management decisions and possibly also regional environmental changes.
The Tshanini Game Reserve was established in 2000 on some land of the community of Manqakulane, but it has not yet been registered.The reserve's creation developed from the initiative of the local community, from as far back as the creation of Tembe Elephant Park.The ideal of the Manqakulane people was to create their own reserve on their own land to counteract high unemployment and to raise funds for the development of the community through ecotourism.For the past 20 years, the land where the Tshanini Game Reserve has been established was utilised by the local people for wood harvesting, livestock grazing, hunting, fruit and honey gathering, and subsistence cultivation where this was viable.It is presumed that large ungulate numbers have always been low in Tshanini Game Reserve, due to the absence of standing water.However, hunting pressure has affected the larger mammal populations, and only small, secretive antelope such as the suni Neotragus moschatus and red duiker Cephalophus natalensis have survived there.
The Tembe Elephant Park and the Tshanini Game Reserve are underlain by the same type of soil and they share the same broad vegetation types.Moll (1977) distinguished the Pallid Bushveld and the Sand Forest Zones in the area, whereas Low & Rebelo (1980) recognised the Subhumid Lowveld Bushveld of the Savanna Biome and the Sand Forest of the Forest Biome.The two reserves lie close to each other with the northern boundary of Tshanini Game Reserve some 6 km due south of the southern boundary of Tembe Elephant Park.Both of these conservation areas lie in the core of the Maputaland Centre of Plant Endemism as described by Van Wyk (1996).In both reserves a rare forest type, known as Sand Forest occurs (Van Wyk 1996;Van Rensburg et al. 1999;Kirkwood & Midgley 1999;Matthews et al. 2001;Van Wyk & Smith 2001).The Sand Forest in this particular area is further defined as the eastern Sand Forest by MacDevette et al. (1989) and Kirkwood & Midgley (1999).In South Africa and in Mozambique, this forest type is restricted to the ancient coastal dune cordons of northern KwaZulu-Natal, and it is home to many rare and unusual plant and animal species (Kirkwood & Midgley 1999;Van Wyk & Smith 2001).Sand Forest in South Africa covers only 354 km², of which 44 % is conserved (Low & Rebelo 1998) with the largest protected area in South Africa in the Tembe Elephant Park (McGeogh et al. 2002).The major part of this vegetation type is found in Mozambique but the extent of it is unknown at present, because of a lack of detailed studies.Cattle grazing, firewood demands and elephant Loxodonta africana impact are the main identified threats for the Sand Forest (Van Wyk 1996;Van Rensburg et al. 1999).
The human population growth rate in Maputaland is high, increasing both by natural growth and immigration, despite a high mortality rate from the AIDS epidemic.
Roads have been constructed through the communities, and safe drinking water is provided.Although these are laudable rural developments, they may become a threat to the conservation of the remote and less exploited areas of northern Maputaland.

Study area
Tshanini Game Reserve is 2 420 ha in extent and its northern boundary lies 6 km due south of the southern boundary of Tembe Elephant Park (Fig. 1).The area consists mainly of a sandy plain that is interspersed with ancient littoral dunes, and is covered by an open to closed woodland with patches of short to tall Sand Forest (Fig. 2).line runs from the southeast to the northwest.
The Tshanini Game Reserve has a mean altitude of 80 m above sea level, and two main ancient littoral dunes occur in it.The dune on the eastern boundary is the southern extension of Nhlela Ridge that extends into the western portion of Tembe Elephant Park.
A beacon is positioned on top of the ridge at an altitude of 103 m above sea level.A second dune runs along the western boundary at an altitude of 95 m above sea level.Between the two main dunes, a third but smaller dune formation is found that starts in the middle of Tshanini Game Reserve and increases in height towards the southern-central part of the reserve.The Nhlole River lies to the east of the western dune cordon, and the lowest point of the reserve is 64 m above sea level in the northeastern corner.

Climate
Rainfall and temperature data for the weather station at Sihangwane at the entrance of Tembe Elephant Park (32.42388 ºE, 27.04316 ºS) appear in Fig. 3. Maputaland lies in a transition zone between the tropics to the north and subtropics to the south.The summers are hot and the winters cool to warm.The summer months are the wettest, although rainfall occurs throughout the year.In the drier winter months, morning mist is a common phenomenon especially in the swamp areas.The relative humidity of the air in summer is higher than in winter (Matthews et al. 2001).

Geology
The underlying geology of Tshanini Game Reserve consists of Cretaceous siltstone units that form the base of the Mozambican Coastal Plain.This formation is overlain by sediments of Miocene and Pleistocene origin.The Maputaland Group overlies the latter.On top of this formation lie the marine, littoral and coastal dune deposits that were formed by successive marine transgressions and regressions.The oldest dunes of the coastal plain date back approximately 5 million years to the early Pleistocene.The recent dunes are as young as 10 000 years, from the late Pleistocene to 500 years ago for the current coastal dunes.The dunes of Maputaland are among the most recent geological formations that are found in southern Africa (Hobday 1976).

Soils
The soils of Tshanini Game Reserve are similar to those described by Matthews et al. (2001)  The floristic data were classified with Braun-Blanquet procedures using the TURBOVEG and MEGATAB computer packages (TURBOVEG for Windows version 1.97, Hennekens & Schaminee 2001).This vegetation classification system was used to refine and interpret the preliminary map of homogeneous physiognomic units to produce a more detailed vegetation map of the Tshanini Game Reserve.As it appeared impossible to digitise every vegetation unit and subunit separately, some units were grouped in mosaics.These mapping units are indicated in Fig. 2.
The homogeneous vegetation units that are common to Tembe Elephant Park and Tshanini Game Reserve were then analysed further to determine the degree of similarity or dissimilarity in terms of species composition and abundance by using similarity indices as described by Mueller-Dombois & Ellenberg (1974).The phytosociological table created for Tshanini Game Reserve and the table obtained from the study of Matthews et al. (2001) for Tembe Elephant Park were used to calculate the indices.Sorensen's qualitative index of similarity (Mueller-Dombois & Ellenberg 1974) that is based on the absence or presence of plant species was used to calculate indices of similarity in plant species composition.To be able to do so, a similar number of comparable relevés were compared in each of the vegetation communities.The following equation was used: Sorensen where: M w refers to the sum of the smaller quantitative values of the species that are common to the two communities; M a is the sum of the quantitative values of all the species in one community; M b is the sum of all the quantitative values of all the species in the other community.
To calculate the values of M w , M a and M b , the Braun-Blanquet cover-abundance values in the phytosociological tables of both reserves were converted into mean cover percentages.To accomplish this each cover-abundance value on the Braun-Blanquet scale was replaced by a cover value, whereafter a mean for the community could be calculated.
Although this is a crude method it does allow quan-Koedoe 47/1 (2004) 14 ISSN 0075-6458 titative comparisons to be made.When comparing vegetation communities, the similarity in terms of absence or presence of species in two communities is more important than the quantitative contribution of each species to a community (Mueller-Dombois & Ellenberg 1974).The latter can be used to refine the comparisons.

Classification
Three major plant communities and eight sub-communities were identified for the Tshanini Game Reserve (Tables 1 & 2, Fig. 2).The Tshanini Game Reserve lies on regic sand and no major geological feature could be identified that plays a role in the differentiation of the plant communities.The Nhlole seepage line area was not sampled and has to be investigated further.It appears that the seepage line may have a duplex soil and that the vegetation type along the Nhlole should be similar to the Spirostachys africana-Berchemia zeyheri closed woodland on duplex soils described by Matthews et al. (2001).This area has been mapped as woodland on clay in Fig. 2.

Similarity indices
The concept of some degree of similarity or dissimilarity between plant communities is difficult to quantify.It is however, possible to use mathematical models to describe such relationships, but because of the mathematical nature of these models, arbitrary limits have to be set (Mueller-Dombois & Ellen-berg 1974).Several indices have been used in the past to quantify the degree of similarity between homogeneous vegetation units or plant communities.Jaccard's Similarity Index is a simple mathematical expression that is based on the ratio of the plant species that are common to two communities, and the total number of species present.Sorensen's Similarity Index is an evolution of Jaccard's and is also used to compare vegetation communities on the basis of the absence or presence of species The vegetation units from Tembe Elephant Park that were used in this comparison are described by Matthews et al. (2001)  The similarity indices indicate that the three main plant communities of Tshanini Game Reserve are similar to their equivalent plant communities and subcommunities described for Tembe Elephant Park (Table 3).These results therefore confirm the prediction made by Matthews et al. (2001) that the plant communities that were described for Tembe Elephant Park can be extrapolated to other parts of Maputaland and can be used for further planning and development of Tshanini Game Reserve and any other similar areas.
The qualitative similarity in species composition between the two sets of data is exceptionally high (Table 3).However, the quantitative similarity indices suggest that there are more pronounced differences between the two reserves.The Tembe Elephant Park has been protected from human utilisation since 1983, although various wildlife species were introduced or re-established there.The Tshanini Game Reserve on the other hand has been devoid of most forms of wildlife for a similar period of time, but it has been subject to human utilisation, cattle grazing and the associated fire regime, especially in the sparse to open woodland areas where grassland occurs.The leaders from the community of Manqakulane still allow cattle grazing on the land of the Tshanini Game Reserve.The high similarity in plant species composition between the two reserves, despite the different utilisation regimes over a period of 19 years is noteworthy.Although no factual data on human population numbers and the intensity of their use of natural resources are available, various authorities in the northern Maputaland region agree that both have increased over the past 19 years.The degree of similarity that still exists in the plant resources suggests that either the human presence and utilisation of these resources in Tshanini Game Reserve has been consistently low, or that the wildlife utilisation in Tembe Elephant Park has been high, or that both forms of utilisation lead to the same pressure on the species.
However, the lower similarity between the two reserves when a quantitative measure is used suggests that there are differences in terms of cover of the species.et al. 1996).In areas that are subjected to animal utilisation and especially elephant presence, a decrease in vegetation cover and density is often observed.This is especially true when the stocking density of animals is higher than the ecological capacity, or the areas are close to natural or artificial watering points (Brits et al. 2002, Mapaure & Campbell 2002, Mosugelo et al. 2002) ture immediately around the park to an increase in human utilisation of these resources.The changes recorded mainly involved the opening up of the canopy in the sand forest, an action they deemed was comparable to the opening up of the canopy by elephants in Tembe Elephant Park.
In the rural community of Manqakulane the situation appears to differ from that described by Van Rensburg et al. (1999), possibly because of the remoteness of the Tshanini Game Reserve as opposed to areas adjacent to Tembe Elephant Park.The latter areas are served by the main road that has become an extraction route for construction wood and especially for firewood.The vegetation adjacent to the road is also harvested for the sale of wood.Human settlements are found up to 2 km south of the main road that passes along the southern boundary of the Tembe Elephant Park.Impact on vegetation surrounding human settlements can be observed as far as 2 km from the settlement location.
The interpretation of the vegetation data suggests that the present human pressure on the Tshanini Game Reserve in northern Maputaland is still low.There is no doubt that the pressure is increasing because of the population increase over the past 10 years (H.Els, Centre for Indigenous Knowledge, University of Pretoria, 0002 Pretoria pers.comm.).However, local people prefer to remain close to the water resources, main roads and arable lands.A low potential for agriculture, the distance from a major road and a lack of water have all kept people away from Tshanini Game Reserve.These factors have therefore contributed to the preservation of this environment.The distance of the Tshanini Game Reserve from the community centre, where most people of the community of Manqakulane have settled, is less than 3 km.However, this distance in such a poor community where vehicles and other means of transportation of goods and resources are not readily available, seems to be sufficient to prevent an excessive impact on the reserve from human utilisation.Most people have to carry the material which they harvest them-selves, often as loads on their head, and this seems to have limited the utilisation of resources further than the immediate vicinity of the settlements.The availability of adequate material for human utilisation in the immediate vicinity of human settlements may also have contributed to the protection of land further away.However, there are indications that a limit of sustainable utilisation has been reached in the vicinity of the human settlements, as suggested by Van Rensburg et al. (1999), and that the people in this community may soon seek to utilise the plant resources further away (Gaugris unpublished data 2003).

Conclusions
A vegetation map for Tshanini Game Reserve and its surrounding areas has been provided.Moreover, the plant communities have been described, and were compared with similar vegetation units in Tembe Elephant Park.This comparison between similar vegetation units shows that species composition is very similar but that plant cover values are significantly higher in Tshanini Game Reserve than in Tembe Elephant Park.These differences will have to be investigated in more detail to establish which condition should be regarded as representative of pristine conditions.The present study suggests that the sand forest in Tshanini Game Reserve has not suffered degradation by human pressure, but that elephants may be affecting the sand forest in Tembe Elephant Park and that they have already changed the plant cover significantly but not the species composition.In general the high intensity wildlife utilisation, notably by elephant, in Tembe Elephant Park is suggested as probable cause for the difference observed in species cover between equivalent communities of the two reserves.The Manqakulane community is still reasonably small and natural resource use is restricted to the vicinity of the settlements.This has apparently preserved large areas from been overexploited.

Fig. 1 .
Fig. 1.Map of Maputaland with the locations of Tembe Elephant Park and Tshanini Game Reserve in northern KwaZulu-Natal, South Africa.

Fig. 2 .
Fig. 2. The vegetation of the Tshanini Game Reserve and surrounding area in Maputaland, northern KwaZulu-Natal, South Africa.

Fig. 3 .
Fig. 3. Climatogram of the Sihangwane Weather Station, Tembe Elephant Park, Maputaland, northern KwaZulu-Natal, South Africa (b = height above sea level, c = duration of observations in years, d = mean annual temperature in °C, e = mean annual precipitation in mm, f = mean daily minimum of the coldest month in °C, g = lowest temperature recorded in °C, h = mean daily maximum of warmest month in °C, i = highest temperature recorded in °C, j = mean daily temperature variation in °C, m = dry season, n = humid season, o = mean monthly rainfall > 100 mm) following Walter (Cox & Moore 1994).
's Index of Similarity = (2c x 100) / A + B where: c = number of species common to both communities A = total number of species in community A B = total number of species in community B. The similarity index of Motyka et al. (Mueller-Dombois & Ellenberg 1974) was used to calculate a quantitative similarity index in terms of species abundances.The equation is: Motyka et al.'s Index of Similarity = (2 M w x 100) / (M a + M b ) as: -The Drypetes arguta-Uvaria lucida subsp.virens sand forest community of the deep sandy areas (dry sands) -The Acacia burkei-Euclea natalensis closed woodland and thicket subcommunity -The Salacia kraussii-Themeda triandra open woodland on sand subcommunity

Table 2
Classification of the vegetation communities for Tshanini Game Reserve in northern KwaZulu-Natal, South Africa 1.The Urelytrum agropyroides-Sapium integerrimum open woodland 1.1.The Albizia versicolor-Diheteropogon amplectens sparse woodland 1.2.The Indigofera podophylla-Albizia adianthifolia ecotonal sparse woodland 1.3.The Antidesma venosum-Urelytrum agropyroides open woodland 1.4.The Fimbristylis complanata-Diheteropogon amplectens open woodland 2. The Sclerocarya birrea-Strychnos madagascariensis closed woodland 2.1.The Cordia monoica-Sclerocarya birrea open to closed woodland 2.2.The Melinis repens-Sclerocarya birrea closed woodland 3. The Ptaeroxylon obliquum-Hymenocardia ulmoides sand forest 3.1.The Rothmannia fischeri-Ptaeroxylon obliquum low to short sand forest 3.2.The Strychnos henningsii-Ptaeroxylon obliquum tall sand forest.ISSN 0075-6458 Phytosociological table of the vegetation of Tshanini Game Reserve in northern KwaZulu-Natal, South Africa Matthews et al. (2001)postulated that clay content, moisture level in the soil and vegetation dynamics were major determinants of vegetation differentiation in Tembe Elephant Park.However, clay content and moisture level differences in the soil of various areas in Tshanini Game Reserve are slight and could not be directly related to the differentiation between plant communities in Tshanini Game Reserve.Except for the sand forest, the plant communities do not have sharp boundaries.The open and closed woodlands form mosaics that grade into each other and the boundaries are difficult to map on an aerial photograph.However, the plant communities are relatively easily recognised in the field.plantspeciesarethetreeAlbizia adianthifolia, the grasses Diheteropogon amplectens and Urelytrum agropyroides and the shrub Acridocarpus natalitius var.linearifolius.ISSN 0075-6458 15 Koedoe 47/1 (2004)Table1

Table 3
A comparison between the vegetation of Tembe Elephant Park and Tshanini Game Reserve by means of the Sorensen SimilarityIndex based on species composition and that ofMotyka et al. (In: Mueller-Dombois & Ellenberg 1974)based on species abundance