bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term changes in the woody vegetation of the Kruger National Park, with special reference to the effects of elephants and fire
Authors: Trollope W.S.W. , Trollope L.A. , Biggs H.C. , Pienaar D. , Potgieter A.L.F.
Published: August 2012

As part of the investigation reviewing the South African National Parks policy on the management of elephants in the Kruger National Park in South Africa it was decided to assess the current density and structural diversity of the woody vegetation in the park as it is affected by elephants and fire. The management policy used till recently, limited the population to approximately 7000 elephants, based on a conclusion that 6000 elephants (1 per 1.94 km2) was the highest number of elephants that could be carried in the Kruger National Park. The inclusion of the effects and interaction of fire in the investigation arises from the general recognition that elephants and fire can have a highly significant impact on the species and structural diversity of tree and shrub vegetation in African savannas. In the absence of quantitative data describing the condition of the woody vegetation in the Kruger National Park, subjective comparisons of changes in the density of large trees were made for the periods 1940 vs 1960 and 1960 vs 1986/89 using aerial photographs based on four of the major vegetation landscape units in the park. The results indicate that in the vegetation landscapes in areas with granitic soils there were no significant changes in the density of large trees between 1940 vs 1960 whereas a moderate decline occurred in the vegetation in the areas with basaltic soils. Conversely during the period 1960 to 1986/89 there was a dramatic decline in the density of large trees in all four major vegetation landscape units. On-site inspections and botanical surveys suggest that the decline in the density of large trees is the result of the effects of the interaction of elephants and fire. This had arisen because during the period 1960 to 1986/89 systematic burning programs had been introduced at the same time as elephant numbers had risen sharply. The results presented suggest that the changes in the woody vegetation do not involve a decrease in species diversity but rather a change in structural diversity where the woody vegetation is being transformed into a short woodland community interspersed with a low density of large trees. It is concluded that if it is desirable to prevent further structural changes to the woody vegetation then the current density of elephants should not be allowed to increase, the frequency of burning should be significantly reduced and the ignition procedure altered to allow or simulate point ignitions of fires.
Recommendations for the conservation and management of humpback dolphins Sousa chinensis in the Algoa Bay region, South Africa
Authors: Karczmarski L. , Cockcroft V.G. , McLachlan A. , Winter P.E.D.
Published: August 2012

The natural history of humpback dolphins Sousa chinensis inhabiting the Algoa Bay region. Eastern Cape, South Africa, was investigated by means of land- and sea-based surveys undertaken between May 1991 and May 1994. This article reviews the findings which are relevant to the conservation of humpback dolphins and provides recommendations for both the conservation and management of this species in Eastern Cape waters. In general, humpback dolphins appear to be typical coastal dolphins which occur in small numbers, have low population growth and depend on restricted inshore resources. Establishment of protected areas where human impact could be limited or controlled seems to be the most effective conservation/management approach. Habitats critical for humpback dolphins in Eastern Cape waters (inshore rocky reefs) and the dolphin's core areas in the Algoa Bay region have been identified. It is recommended that a conservation and management zone (marine sanctuary) in the Algoa Bay region be established and a suitable site for it is identified. Given adequate legislation and proper management, this area could be used for the development of ecotourism, including dolphin-watch operations, which would further stimulate interest in coastal conservation.
A check list of the spider fauna of the Karoo National Park, South Africa (Arachnida: Araneae)
Authors: Dippenaar-Schoeman Anna S. , Leroy Astri , De Jager Marie , Van den Berg Annette
Published: August 2012

A check list of the spider species of the Karoo National Park collected over a period of 10 years is presented. Thirty-eight families, represented by 102 genera and 116 species have been collected. Of these species, 76 (66.4 ) were wanderers and 39 (33.6 ) web builders. The Araneidae have the highest number of species (14) followed by the Thomisidae (10) and the Gnaphosidae (8), while 14 families are represented by a single species. Information on spider guilds, their habitat preference and web types is provided. This study forms part of the South African National Survey of Arachnida (SANSA).
Changes in the water quality of the Wilderness and Swartvlei lake systems, South Africa
Authors: Russell I.A.
Published: August 2012

Measurements of water temperature, salinity, total dissolved solids, pH, dissolved oxygen, secchi disk depth, turbidity and total suspended solids were undertaken monthly in the Wilderness and Swartvlei lake systems between 1991 and 1997. The range of most water quality variables is wider than recorded in earlier studies. Potential causes are discussed for each variable, and include both anthropogenic modification of the quantity and timing of water movements within the lakes, as well as higher sampling and longer duration studies resulting in more accurate recording of natural variability. Historical data on total dissolved solids (1978 to 1990) were combined with data collected in these surveys to assess the occurrence of trends in relation to freshwater inflows. Long-term (19-year) changes in total dissolved solids have occurred in all lakes, with decreases during high runoff periods and increases during low runoff periods. There is little evidence of unidirectional change in total dissolved solids despite increased water abstraction from influent rivers.
Freshwater fish of the Wilderness National Park
Authors: Russell I.A.
Published: August 2012

The study aimed to determine the distribution and relative abundance of freshwater fish in the Wilderness National Park. Fish assemblages in the Touw and Duiwe rivers were sampled in 1997 and 1998, with a total of 327 fish from nine species recorded. Indigenous species included two freshwater species (Pseudobarbus afer, Sandelia capensis), two catadromous species (Anguilla mossambicus, Myxus capensis), and two estuarine species (Monodactylusfalciformis, Caffrogobius multifasciatus). Three of the nine recorded species were alien (Micropterus dolomieu, Micropterus salmoides, Gambusia affinis), with the Micropterus spp., in particular, likely to have a substantial negative influence on indigenous species. A further one indigenous species, two translocated indigenous species, and five estuarine species could potentially be recorded in these rivers. River catchment management actions to restore perennial flow to the Duiwe River, to prevent the attenuation of floods, and to prevent further establishment and spread of alien and translocated biota are required to conserve indigenous fish assemblages.
A demographic model to predict future growth of the Addo elephant population
Authors: Woodd A.M.
Published: August 2012

An age-structured demographic model of the growth of the Addo elephant population was developed using parameters calculated from long-term data on the population. The model was used to provide estimates of future population growth. Expansion of the Addo Elephant National Park is currently underway, and the proposed target population size for elephant within the enlarged park is 2700. The model predicts that this population size will be reached during the year 2043, so that the Addo elephant population can continue to increase for a further 44 years before its target size within the enlarged park is attained.
Overview of the fire management policy of the Kruger National Park
Authors: Biggs H.C. , Potgieter A.L.F.
Published: August 2012

New developments in fire management policy in the Kruger National Park are sketched against the background of changing attitudes towards ecosystem management. The experimental burning plots established in the mid-1950s are discussed briefly, as is the almost forty-year era of rotational block- burning. The lightning-driven fire policy initiated in 1992 and currently aimed at by park management is discussed, with comments on its early performance. More recent revision of the management plan stressed maximisation of appropriate research benefits from the experimental burning plots, con- doned the lightning approach for the present, but stressed the absolute necessity of the park not finding itself in the 1992 position again, where a major change in policy has to be made with no comparative evidence from other systems. To this end, a major landscape-scale fire management trial has been planned for implementation starting in April 2000. It is sheduled to run over a twenty-year period, and will be placed at four localities representing different major landscapes in the park. It will compare the effects of three different fire systems (lightning, patch mosaic, and range condition burning systems) on biodiversity elements crucial to the park's mission. The rationale for, layout of, and criteria for deciding on the outcome of the trial are discussed, as well as the trade-offs that were made to enable the trial to be of such a large scale and still fit into overall park planning. The impact of the trial on the park's monitoring programme is discussed.
The impact of an increasing elephant population on the woody vegetation in southern Sabi Sand Wildtuin, South Africa
Authors: Hiscocks Kay
Published: August 2012

In 1961, a fence was erected between privately owned Sabi Sand Wildtuin (SSW) and the Kruger National Park (KNP), which largely prevented elephants entering the SSW. In 1993, the fence was removed. This lead to a rapid influx of elephants into the SSW during the winter months, most of which move back into the KNP during the wet summer season. In 1993, the SSW elephant population was 1/1045 ha but increased to 1/305.8 ha in 1996. It more than doubled to 1/146 ha in 1998. This study was undertaken on the property Kingston, in southern SSW, to assess the impact of elephants on woody vegetation and determine why they show seasonal dietary preferences for specific tree parts. Vegetation utilisation was recorded on a five kilometer transect of vehicle track in 1996 and repeated in 1998. From the transect, species density was calculated for those trees impacted on. Trees that had been newly bark stripped were recorded in 1996 and 1998. Cambium samples were collected in summer and winter from eight tree species. Field observations of elephants impacting on woody vegetation augmented the data base. Transect analysis showed a strong correlation between tree utilisation and density. The most visual damage was of Combretum apiculatum, Acacia burkei, Pterocarpus rotundifolius and Grewia species. Tree damage increased by 73 from 1996 to 1998. Significantly higher levels of nitrogen, sodium and magnesium were found in the species most regularly bark stripped. Bull elephants were responsible for 94 of the trees seen uprooted. The results suggested that SSW can sustain the present elephant population, but further influx at the present rate of increase, will have a negative impact on the reserve.
An approach to assessing the financial viability of bush clearing on game ranches in savanna regions
Authors: Schmidt A.G. , Jordaan J.W.
Published: August 2012

An approach to assessing the financial viability of bush clearing on game ranches in savanna regions is presented, using data on the rates of change of herbaceous phytomass and tree density following bush clearing. Financial gain is calculated from an increase in grazing capacity with an increase in herbaceous phytomass. The financial gain is offset against the financial loss due to a decrease in browsing capacity with a decrease in bush density. Profitability is calculated by calculating the net present value of the net financial gain over the effective duration of the bush clearing exercise. Shortcomings in the approach are identified and a need for more appropriate long-term data is indi-cated.
The phytosociology of the De Rust section of the Mountain Zebra National Park, Eastern Cape
Authors: Brown L.R. , Bezuidenhout H.
Published: August 2012

As part of a vegetation survey programme for conservation areas in South Africa, the plant communities of the De Rust section of the Mountain Zebra National Park were investigated. From a TWINSPAN classification, refined by Braun-Blanquet procedures, 14 plant communities, which can be placed into six major groups, were identified. A clas- sification and description of these communities, as well as a vegetation map are presented. Associated gradients in habitat were identified by using an ordination algorithm (DECORANA). The diagnostic species as well as the prominent and less conspicuous species of the tree, shrub, herb and grass strata are outlined.
Long term effects of fire frequency and season on the woody vegetation dynamics of the Sclerocarya birrea/Acacia nigrescens savanna of the Kruger National Park
Authors: Enslin B.W. , Potgieter A.L.F. , Biggs H.C. , Biggs R.
Published: August 2012

A lack of knowledge together with vacillating fire management approaches in the Kruger National Park until the mid 1950s, gave rise to a long term fire research experiment aimed at shedding light on savanna responses to various combinations of fire fre- quencies and seasons. This trial was laid out in 1954 in four of the six major vegetation zones of the park. With the future of the experiment now being reconsidered, full scale vegetation surveys have been conducted on all the plots and compared to the surveys done in 1954. This paper examines the woody vegetation responses to fourteen fire treatments in the Knobthorn/Marula savanna. Parameters of interest were woody species composition responses, together with tree & shrub density and structural changes. The results indicate that no significant changes in woody species had occurred for the peri- od 1954 vs 1998, while density decreased on biennial and increased on triennial treatments. The proportion of single stemmed plants increased over the period. Season of burn has a marked effect on structure, with April and August burns giving rise to the largest basal areas but the lowest heights. Environmental parameters such as climate, varying herbivory and differing soils, and their respective interactions on vegetation morphology, together with fire behaviour, further influenced results.
Distribution and density of Cubitermes Wasmann (Isoptera: Termitidae) mounds in the northern Kruger National Park
Authors: Meyer V.W. , Braack L.E.O. , Biggs H.C.
Published: August 2012

This paper provides fundamental information on distribution and density of the genus Cubitermes, Wasm. quantified for future monitoring. After distribution trends have been established, changes in Cubitermes density over time can be brought into contention with other factors in the Kruger National Park, such as the impact of fire frequency, water distribution, and elephant density on these insects. At least ten 2 ha belt-transects were undertaken in each of the 20 northern landscape zones of the KNP. Termite mounds were recorded and their activity within was determined. Cubitermes accounts for 29.8% of all active termite mounds in the northern KNP, with an average density of 0.33 mounds/ha. Cubitermes favours the Nwambiya Sandveld (zone 32). These termites occur in high density in the Klipkoppies 1 land type (Gorge), but in low densities in the Phalaborwa 10-12, Bulweni 1-3, Letaba 1-7 and Pafuri 3-6 land types. Cubitermes mounds tend to occur in high numbers on the Nzhelele formation (Mn) (sandstones; quartzite; basalt). Mounds of this genus in the Far North are highly concentrated on the Gaudam and Moriah soil series of the Hutton form, suggesting that these termites prefer very sandy soils with medium to coarse particles.
Weed management practices in natural ecosystems: a critical overview
Authors: Reinhardt C.F.
Published: August 2012

Increasing public pressure against the use of pesticides and other agricultural inputs has placed increased emphasis on the development of ecologically based pest management. One distinct reaction of the Weed Science discipline has been the swing away from herbicide research to increased research on the basic biology and ecology of weeds in hopes of reduced reliance on "technological crutches" such as herbicides and other practices that are potentially harmful to the environment. Biological control is the long-standing alternative to the use of herbicides and interest in the former practice has been boosted by the realization that the use of herbicides may lead to the development of herbicide resistance in weed populations, and that herbicide residues occur in surface and groundwater. Supporters of herbicide use would point out that biological control is generally not effective in crop production systems, and is basically slow-acting. Debates between protagonists for the exclusive use of one or the other weed management practice tend to obscure the benefits that integration of different techniques are likely to have. For natural ecosystems it is proposed that integration of the more subtle practice of biological control with the use of herbicides, which relatively quickly overwhelm a biological system with mortality, is likely to be the most effective weed management tool. Different weed management practices that could be considered in natural ecosystems are discussed in terms of three key performance rating criteria, viz. activity, selec- tivity and persistence In this concise review, general discussion is focussed on the fundamentals of weed management practices, with the view to promote concept-based approaches that are critical for the development of effective weed management strate- gies.
Impact of fire frequency on woody community structure and soil nutrients in the Kruger National Park
Authors: Shackleton C.M. , Scholes R.J.
Published: August 2012

Although fire is recognised as an important determinant of the structure and function of South African savannas, there are few studies of long-term impacts. Controlled burning blocks of contrasting fire season and frequency have been maintained throughout the Kruger National Park for almost 50 years. This paper reports on a quantitative study of the Satara plots to determine the long-term impacts of fire frequency on woody community structure and soil nutrients. Increasing fire frequency significantly decreased woody plant basal area, biomass, density, height, and mean stem circumference. The number of stems per plant and the proportion of regenerative stems increased with increasing fire frequency. Effects on species richness of woody plants were inconsistent. There were no significant differences attributable to fire frequency for any of the soil variables except organic matter and magnesium. Organic carbon was highest in the fire exclusion treatment and lowest in soils from plots burnt triennially. Magnesium levels were greatest in the annually burnt soils and least in the triennial plots.
An updated check list of the ichthyofaunal species assemblage of the Tsitsikamma National Park, South Africa
Authors: Wood A.D. , Brouwer S.L. , Cowley P.D. , Harrison T.D.
Published: August 2012

This work summarises ichthyological research in the Tsitsikamma National Park (TNP) over the past 20 years, and an updated species check list of fishes has been compiled. A total of 202 species of fishes from 84 families has been recorded within the boundaries of the national park. All species which have been included were identified from visual transects, rotenone collections, estuarine surveys, ichthyoplankton surveys, mark/recapture studies and personal observations. The ichthyofauna is a diverse assemblage of chondrichthyans and teleosts, 75 (37.1) of which are components of commercial and recreational fisheries along the east coast. Surveys also indicate that the TNP provides refuge to all life history stages for 17 of the commercial and recreational teleost species. The need for more detailed collections of previously neglected teleost and chondrichthyan groups is recognised. The number of species and diversity demonstrates that the TNP appears not only to afford protection to exploited fish species, but also fulfills one of the basic requirements of Marine Protected Areas@that of conserving biodiversity (of fishes).
Mkomazi: the Ecology, Biodiversity and Conservation of a Tanzanian Savanna
Authors: Knight Michael
Published: August 2012

Mkomazi Game Reserve (MGR) , a relatively little known conservation area in north eastern Tanzania, is described in this rather voluminous treatise spanning a total of 37 chapters.
Dispersal of Dactylopius opuntiae Cockerell (Homoptera: Dactylopiidae), a biological control agent of Opuntia stricta (Haworth.) Haworth. (Cactaceae) in the Kruger National Park
Authors: Foxcroft L.C. , Hoffmann J.H.
Published: August 2012

Chemical control efforts, the introduction of Cactoblastis cactorum and attempted releases of Dactylopius opuntiae Cockerell into the expanding infestation of Opuntia stricta in the Skukuza region of the Kruger National Park (KNP) have had limited suc- cess in preventing the spread and densification of 0. stricta. To boost the biological control component, a new strain of D. opuntiae was introduced into KNP during 1997. The new strain established readily and has destroyed large clumps of plants in the vicin- ity of the release site. A large-scale redistribution programme with D. opuntiae is now needed to exploit this biological control agent to the full. In order to match the frequency of manual releases with the natural rates of spread of the insects, surveys were conducted under field conditions to determine the dispersal abilities ofD. opuntiae, with regard to rate and direction of movement. Dispersal of D. opuntiae was found to be slow and restricted and that the insects need to be redistributed by placing them onto plants at approximately 10 m intervals to ensure that they become quickly and evenly distributed on the weed. This information will be crucial in the revision of the integrated management plan for 0. stricta in the KNP, in integrating the cochineal and other control mechanisms.
Technology for alignment of participants in nature conservation: a case study at the Southern African Wildlife College
Authors: Sonnekus I.P. , Breytenbach G.J.
Published: August 2012

Alignment between the participants in any process allows for effective and sustainable utilisation of resources. When alignment lacks, resources are diverted to address issues that are peripheral to the central issue at hand.'Ideally, all resources should be used for the main purpose of the exercise and not to deal with unnecessary problems. To illustrate the use of this alignment technology, it was applied to optimise both the participation of and benefit to the contributors at the Southern African Wildlife College (SAWC) as part of an academic course module. The alignment process ensures that each student becomes aware of his/her importance in the process and investigates the expectations of all the role players. The scene is set for answering Four Magic Questions (4MQ) and functions are developed for achieving the required outcomes. In order to stabilise the alignment, values management technology is used which enables the students to recognise and begin to deal with differing management styles.
Towards an adaptive management approach for the conservation of rare antelope in the Kruger National Park - outcome of a workshop held in May 2000
Authors: Grant C.C. , Van der Walt J.L.
Published: August 2012

A precipitous drop in rare antelope numbers specifically roan (Hippotragus equinis) sable (Hippotragus niger) and tsessebe (Damaliscus lunatus) since 1986 has become one of the main concerns of management. The zebra (Equus burchelli) population in the preferred habitats of these species had increased with the development of artificial waterpoints especially in the areas occupied by roan and tsessebe, and these events are hypothesised to be the main cause of the decline. Closure of artificial waterpoints resulted in moving the high-density, water-dependent zebra from the northern basalt plains, the preferred roan habitat. However, the expected responding increase in the rare antelope populations did not materialise. This lack of response over six years necessitated a critical re-evaluation of the management of rare antelope in the Kruger National Park. Subsequently, a workshop was held at Skukuza during May 2000. The options for adaptive management of the declining rare antelope populations, which was discussed at the workshop, is the subject of this manuscript. The participants felt that the removal/closure of artificial waterpoints was the most unintrusive management tool available to move high density grazers from the habitats preferred by rare antelope. Waterpoints to be closed should be carefully evaluated, and time allowed for rare antelope to respond to habitat changes. Boosting populations of roan and tsessebe by supplementing animals was seriously considered, with the proviso that it should be done under favourable circumstances. Small patch fires that could provide green grazing over extended periods were recommended. Predator control was discussed but could not obtain general support as a viable option in the Kruger National Park.
The February 2000 floods on the Sabie River, South Africa: an examination of their magnitude and frequency
Authors: Heritage G.L. , Moon B.P. , Jewitt G.P. , Large A.R.G. , Rountree M.
Published: August 2012

The floods that affected much of Southern Africa in February 2000 have been reported as the largest in living memory by many observers. However, the force of the floods damaged the majority of the gauging stations located on the affected rivers, many of which were not constructed to measure flows of such a magnitude. This paper presents an estimation of the peak flood discharge on 6 February 2000 for the bedrock influenced Sabie River in the Kruger National Park, by simulating the hydraulic and geometric characteristics of the peak flow and relating these to the roughness character of the channel. Peak water surface slope data in the form of strandline measurements at channel type breaks along the river were collected for six sites along the Sabie River within the Kruger National Park. Flood conditions within each channel type were considered to approximate to uniform flow. The cross-sections are located between major tributary inputs allowing for approximate sub-catchment flow contributions to be estimated. The results indicate that the flow peaked at around 3000 mVs at the Kruger Gate entrance to the Kruger National Park, increasing to approximately 5500mVs at Skukuza and 7000 mVs at Lower Sabie close to the Mozambique border following inputs from the Sand River sub-catchment. These estimates compare well with the simulated rainfall runoff total of 4300 mVs at Skukuza, however, precipitation inputs over the lowveld appear to indicate that the discharge only rises to 4950 mmVs at Lower Sabie. A flood flow of this magnitude has never been experienced based on the simulated flow data generated by the ACRU hydrological model calibrated against measured flows therefore suggesting a return period in excess of the 60 years of record.
Comments on article : Technology for alignment of participants in nature conservation: a case study at the Southern African Wildlife College
Authors: Moll Eugene
Published: August 2012

The authors, I.P. Sonnekus and G.J Breytenbach, were responsible for facilitating students in the 'Team Building' module for the Long Course Diploma in February, and for some training in March and October 2000.
The genus Discolaimus in southern Africa. 2. Discolaimus constrictus sp. n. and D. monoplanus Heyns, 1963 (Nematoda: Dorylaimida)
Authors: Heyns J.
Published: August 2012

Discolaimus constrictus sp.n. is differentiated from D. mucurubanus Loof, 1964, the only other species in the genus in which the basal bulb is set off by a constriction, by its larger size, relatively shorter oesophagus, relatively shorter tail and more posteriorly situated vulva. In general appearance it more closely resembles D. affinis Loof, 1964, D. similis Thorne, 1939 and D. silvicolus Sauer & Annels, 1985. A large population of D. monoplanus Heyns, 1963 is described from Namibia. The remarkable similarity between D. monoplanus, D. texanus Cobb, 1913 and D. brevis Siddiqi, 1964 is pointed out, and the biometrics of all recorded populations of these three species are tabulated and briefly discussed.
The role of flowering plant species in the survival of blackflies (Diptera: Simuliidae) along the lower Orange River, South Africa
Authors: Myburgh E. , Bezuidenhout H. , Neville E.M.
Published: August 2012

This study is an investigation of the role that plants play in the survival of adult blackflies by providing shelter and carbohydrate food. A detailed phenological study of the 29 most abundant plant species in the Augrabies Falls National Park showed that throughout the year the percentage of plant species flowering was remarkably constant. It is therefore unlikely that the availability of carbohydrates would limit adult Simulium survival at any time of the year. Blackflies were recorded feeding on the flowers of Pappea capensis. Acacia karroo, A. mellifera, Tamarix usneoides, Ziziphus mucronata, Scholia afra and Sisyndite spartea. An additional survey showed that another 64 plant species flowered throughout the year, and these can be regarded as potential carbohydrate sources. Blackflies were observed sheltering in dense shrubs and trees that provide protection against predation and harsh environmental conditions. This study suggests that vegetated drainage lines are the means by which adult blackflies survive dispersal away from the river. It is concluded that carbohydrate scarcity cannot be considered a limiting factor to adult blackfly survival along the lower Orange River.
Freshwater fishes of Bontebok National Park
Authors: Russell I.A.
Published: August 2012

Fish assemblages were sampled at six sites in the Breede River in the Bontebok National Park during 1999 and 2000. A total of 380 fish from 12 species was recorded. Indigenous fish collected included one freshwater species (Barbus andrewi), two catodromous species (Anguilla mossambica, Myxus capensis). and three estuarine species (Gilchris- tella aestuaria, Monodactylusfalciformis, Mugil cephalus). Four of the species recorded were aliens (Tinea tinea, Lepomis macrochirus, Micropterus salmoides, Micropterus dolomieu) and two species translocated from other South African rivers (Tilapia sparrmanii, Clarias gariepinus). A further two indigenous species (Sandelia capensis, Pseudobarbus biirchelli) could potentially occur within the park, though the high abundance of alien predators means that there is little chance for recolonisation from tributaries higher in the Breede River system. There is little opportunity to meaningfully conserve most indigenous freshwater fish in Bontebok National Park.
Scanning electron microscopical investigation of the waterbuck louse Bovicola (syn. Damalinia) hilli found at the Rietvlei Nature Reserve near Pretoria
Authors: Turner M.L. , Baker C. , Marais R.
Published: August 2012

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Natural mortality amoung four common ungulate species on Letaba Ranch, Limpopo Province, South Africa
Authors: Cronje H.P. , Reilly B.K. , Macfadyen I.D.
Published: August 2012

Five years of mortality data of impala Aepyceros melampus, blue wildebeest Connochaetes taurinus, buffalo Syncerus caffer and kudu Tragelaphus strepsiceros have been used to describe the minimum mortality profiles of the respective species in an open savanna system with the full compliment of predators. Predation is the principle cause of natural mortalities on the study site, Letaba Ranch, which is adjacent to the Kruger National Park. The principle cause of impala mortality are leopards Panthera pardus and wild dogs Lycaon pictus. Lion Panthera leo were major contributors to the mortality of wildebeest and buffalo. Anthrax Bacillus anthracis was the main cause of kudu mortality.
Natural woodland vegetation and plant species richness of the urban open spaces in Gauteng, South Africa
Authors: Grobler C.H. , Bredenkamp G.J. , Brown L.R.
Published: August 2012

It is estimated that approximately 60 % of the world’s population will be living in urban areas by 2025. In Gauteng, the most densely populated province in South Africa, the natural open spaces are continually under threat from development. Vegetation is the most physical representation of the environment on which all animals are ultimately dependent. In order to evaluate an areas potential for development or conservation it is necessary to make a thorough inventory of the plant communities and their associated habitats. A survey of the natural woodlands was undertaken as part of a project describing the vegetation of the natural open spaces within the Gauteng region. Relevés were compiled in 73 stratified random sample plots in selected open spaces within the study area. A TWINSPAN classification, refined by Braun-Blanquet procedures, indicated six woodland communities that can be grouped into two major woodland communities. A classification and description of these communities as well as their species richness are presented. The results indicate that there are still patches of well-preserved natural vegetation within the study area and contribute to the limited knowledge that presently exists for the vegetation of the area.
Floristic analysis of the Mountain Zebra National Park, Eastern Cape
Authors: Pond U. , Beesley B.B. , Brown L.R. , Bezuidenhout H.
Published: August 2012

As part of a larger project to assess the vegetation dynamics and conservation potential of the enlarged Mountain Zebra National Park, a checklist was produced to determine the plant species richness for this area. Six hundred and eighty species, represented by 333 genera and 87 families were identified. One hundred and eighty species belong to the Monocotyledoneae and 479 species to the Dicotyledoneae. By far the largest families are the Asteraceae with 129 and the Poaceae with 82 species. Thirteen Red Data species were recorded. A number of fynbos elements were encountered, the most noteworthy being two families endemic to the Cape Floristic Region, the Penaeaceae and Grubbiaceae. A very high species to square kilometre ratio of 5.05 supports the area’s rich floristic composition.
Some ecological factors influencing the breeding success of the Brenton Blue butterfly, Orachrysops niobe (Trimen) (Lepidoptera: Lycaenidae)
Authors: Edge D.A.
Published: August 2012

The Brenton Blue butterfly, Orachrysops niobe (Trimen, 1862) (Lepidoptera:Lycaenidae), is endemic to the southern Cape and is currently listed as Endangered. This study looks at some of the key ecological factors influencing the breeding success of the species—host plant abundance and condition, nectar sources, climate/ microclimate, and vegetation management techniques. The adult butterfly population was monitored over an entire breeding season; host plants were identified and individually monitored; and egg counts were done. This enabled the effects of a number of different management techniques to be evaluated (burning, cutting, physical removal of invasive elements, and combinations thereof). A fivefold increase in the population of O. niobe was observed over the breeding season. This increase was positively correlated to a similar increase in host plant abundance in the areas where cutting and physical removal of invasive elements was practiced. Burning, by contrast, appeared to have a negative impact on host plant and butterfly abundance over the same period. Impacts of other factors such as climate, nectar sources and the natural strength of the second brood are discussed. A hypothesis, of megaherbivore activity as the principal historical disturbance mechanism promoting locally favourable conditions for O. niobe to establish and maintain colonies, is proposed. Recommendations for reserve management and future research are made.
A check list of the spider fauna of the Western Soutpansberg, South Africa (Arachnida: Araneae)
Authors: Foord S.H. , Dippenaar-Schoeman Anna S. , Van der Merwe M.
Published: August 2012

By virtue of its geological history and geographical location the Soutpansberg constitutes a refuge for a high diversity of organisms. The Western Soutpansberg forms part of the Savanna Biome and is presently the area with the highest concentration of Natural Heritage Sites in South Africa. A unique private initiative is under way to improve its national and international conservation status in a bid to conserve the mountain. A checklist of the spider species of the Western Soutpansberg collected over a five-year period is presented. Forty-six families, represented by 109 genera and 127 species have been collected. Of the species collected, 81 (64 %) were wandering spiders and 46 (36 %) web builders. The Thomisidae have the highest number of species (15) followed by the Araneidae and the Salticidae with 10 species each. Ninety-six genera are represented by a single species. Ninety six percent of the species collected are new records for the area. This survey is the first for the area and forms part of the South African National Survey of Arachnida (SANSA).
Monitoring the vegetation structure of south-central Etosha National Park using terrestrial photographs
Authors: Hipondoka M.H.T. , Versfeld W.D.
Published: August 2012

In 1984, a ground-based, photographic library was initiated for monitoring the vegetation dynamics in Etosha National Park. Over 400 photographic points were selected. At these points, panchromatic photographs were taken at intervals of six years. This study was undertaken to assess the applicability of this terrestrial photographic library in characterising the dynamics of the vegetation structure in south-central Etosha National Park. The methods employed include field validation, visual photograph interpretations, spatial analysis, and aggregated two-dimensional tables. Results, though patchy in nature, show that the vegetation structure at 63 % of the sites covered remained either unchanged or increased over the 15-year study period. The patchiness of the photo points can be exploited and be treated as training sites for corresponding satellite image classifications to provide continuous ground coverage results.
Diets of impala from Kruger National Park: evidence from stable carbon isotopes
Authors: Sponheimer M. , Grant C.C. , De Ruiter D.J. , Lee-Thorp J.A. , Codron D.M. , Codron J.
Published: August 2012

Impala are known to exhibit dietary flexibility, relying primarily on browse in some areas and graze in others. In this study we use stable isotope analysis of faeces and hair to examine the diets of Impala in Kruger National Park. As expected, the data show that Impala are mixed-feeders and highly distinct from grazing buffalo and browsing kudu. Moreover, Impala, Buffalo, and Kudu faeces contain 2.1 %, 1.4 %, and 2.9 % nitrogen respectively, suggesting that Impala diets are of intermediate quality. There are also marked differences between Impala populations in the northern and southern regions of the park. The northern Impala graze less than their southern counterparts. This difference probably reflects decreased availability of herbaceous forage in the mopane-dominated north. Males and females also have different diets, with males grazing more than females.
Plant communities of the Ebenhaezer section of the Mountain Zebra National Park
Authors: De Klerk J. , Brown L.R. , Bezuidenhout H.
Published: August 2012

The long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. Because ecosystems react differently to different management practices, it is important to have a description and classification of the vegetation of an area available. As part of a vegetation survey programme for the newly acquired farms to be incorporated into the Mountain Zebra National Park, the vegetation of the Ebenhaezer section was investigated. Ahierarchical classification, vegetation map, description and ecological interpretation of the plant communities of the study area are presented. ATWINSPAN classification, refined by Braun-Blanquet procedures revealed eight distinct plant communities. Habitat factors associated with differences in vegetation include topography, soil form and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers.
A revised list of alien plants for the Kruger National Park
Authors: Foxcroft L.C. , Henderson L. , Nichols G.R. , Martin B.W.
Published: August 2012

Alien plants recorded in the Kruger National Park are listed, providing an update of species that have been recorded since the last published list in 1988. The serious consequences that invasive alien plants pose are widely recognised internationally and are regarded as the greatest threat to the Kruger National Park. It is extremely important to maintain an updated list of species to use as a reference and from which to monitor changes in the influx of invasive species. The list contains the invasive status of the plants, current impact, habitat types, biological control status and status according to the Conservation of Agricultural Resources Act (CARA), Act 43 of 1983, as amended in March 2001. The list comprises 370 species, of which 121 are invaders and two are transformer weeds, which may cause considerable damage and alterations to the indigenous biodiversity. A total of 91 species listed herein are also listed in the CARA regulations or are proposed additions to the CARA regulations.
Analysis of the riparian vegetation (Ia land type) of the proposed Vhembe-Dongola National Park, Limpopo Province, South Africa
Authors: Götze A.R. , Cilliers S.S. , Bezuidenhout H. , Kellner K.
Published: August 2012

The establishment of the Vhembe-Dongola National Park has been an objective of several conservationists for many years. The ultimate objective is that this park would become a major component of a transfrontier park shared by Botswana, Zimbabwe and South Africa. The aim of this study was to identify, classify and describe the plant communities present in the Ia land type of the proposed area for the park. Sampling was done by means of the Braun-Blanquet method. A total of 70 stratified random relevés were sampled in the Ia land type. All relevé data was imported into the database TURBOVEG after which the numerical classification technique TWINSPAN was used as a first approximation. Subsequently Braun-Blanquet procedures were used to refine data and a phytosociological table was constructed, using the visual editor, MEGATAB. From the phytosociological table four plant communities were identified and described in the Ia land type. The ordination algorithm, DECORANA, was applied to the floristic data in order to illustrate floristic relationships between plant communities, to detect possible gradients in and between communities and to detect possible habitat gradients and/or disturbance gradients associated with vegetation gradients.
A comparison of woody browse selection by hand-raised, boma-adapted and wild black rhinoceros, Diceros bicornis, L. in Matusadona National Park, Zimbabwe
Authors: Matipano G.
Published: August 2012

Differences in woody browse selection between hand-raised (and subsequently released), boma-adapted and wild black rhinoceros, Diceros bicornis, L. were studied in Matusadona National Park between December 1999 and July 2000. Boma-adapted rhinoceros were animals that were subjected to hand-raising and were kept in bomas (enclosures) over night. The feeding behaviour was different between the three rhinoceros groups. All rhinoceros groups utilised and selected for a few browse species in common, at different preference levels in the same habitat types according to season. Wild rhinoceroses browsed most in Colophospermum-Terminalia-Combretum woodland in the wet season and in thicket in the dry season. Hand-raised rhinoceroses browsed most in Colophospermum-Terminalia-Combretum woodland and boma-adated rhinos in thickets in both the wet and the early dry seasons. Hand-raised and bomaadapted rhinos changed their habitats less for browse selection than wild rhinos. This can be ascribed to a relative restriction of home range in the hand-raised group and a herding effect for the boma-adapted animals. These situations might have accounted for differences in seasonal browse selection by the rhinoceros groups.
Fuelwood availability and use in the Richtersveld National Park, South Africa
Authors: Shackleton C.M. , Guthrie G. , Keirungi J. , Stewart J.
Published: August 2012

Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.