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- Volume 55, Issue 1, 2013
Koedoe : African Protected Area Conservation and Science - Volume 55, Issue 1, 2013
Volume 55, Issue 1, 2013
Author M. Brock FentonSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –3 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1140More Less
With over 130 species, bats are the most diverse group of mammals almost everywhere in sub-Saharan Africa. Since 2000, two books (Monadjem et al.. 2010; Taylor 2000) have made it much easier to appreciate this reality. Species previously unrecognised are frequent discoveries (e.g. Taylor et al. 2012). Whilst most species are mainly insectivorous, some rely more directly on plants, taking fruit and visiting flowers to obtain nectar and pollen. The combination of mobility, long lifespan and diversity of trophic roles makes bats potentially valuable as indicators of ecosystem health (Cumming & Spiesman 2006). Lack of detailed information, however, makes it easy to overlook bats when focusing on issues of conservation.
Herbaceous species diversity patterns across various treatments of herbivory and fire along the sodic zone of the Nkuhlu exclosures, Kruger National Park : original articleSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –6 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1112More Less
Understanding relationships between large herbivores and plant species diversity in dynamic riparian zones is critical to biodiversity conservation. The Nkuhlu exclosures in the Kruger National Park (KNP) provided opportunity to investigate spatial heterogeneity patterns within riparian zones, as well as how these patterns are affected by fire and herbivory. A monitoring project was initiated to answer questions about the dynamics of the herbaceous layer and was aimed at determining, (1) whether there exists meaningful variance in herbaceous plant species richness and diversity across different treatments in the ecologically sensitive sodiczone and (2) whether an increase in herbaceous biomass, an artefact of herbivory and fire exclusion, suppresses herbaceous plant species diversity and richness. Herbaceous vegetation was sampled in two 1 m2 circular sub-plots in the eastern and western corners of 81 fixed plots. The biomass of each plot was estimated with a disc pasture meter (DPM) diagonally with the plot. DPM-readings were converted to kg/ha, according to the latest conversions for the Lowveld Savanna. Species richness and biomass showed significant variance across treatments, whereas no significant variation in herbaceous species diversity was perceived.Combined treatment of fire absence and herbivore presence contributed to higher forb species richness in the sodic zone. Biomass is significantly higher in fully fenced areas where herbivores are excluded, as opposed to the open and partially fenced areas. Although no significant variation was recorded for diversity across treatments, lowest diversity was recorded in the absence of all herbivores, especially in combination with fire treatment. Therefore herbivores are essential in sustaining herbaceous plant species richness in the sodic zone, whilst no significant results were found with regard to their effect on species diversity. Although statistically non-significant, fire seems to suppress species richness.
Conservation implications:This study could be used as framework to advance and develop science-based management strategies for, at least, the sodic zones of the KNP. Research in these exclosures will create better understanding of these landscapes, benefit ecosystem conservation planning of national parks and also provide valuable long-term information on key ecological processes.
Fire regimes in eastern coastal fynbos : imperatives and thresholds in managing for diversity : review articleSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –9 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1104More Less
Until recently, fire ecology was poorly understood in the eastern coastal region of the Cape Floral Kingdom (CFK), South Africa. Rainfall in the area is a seasonal and temperatures are milder than in the winter-rainfall and drier inland parts of the CFK, with implications for the management of fire regimes. We synthesised the findings of a research programme focused on informing ecologically sound management of fire in eastern coastal fynbos shrublands and explored potential east-west trends at the scales of study area and CFK in terms of fire return interval (FRI) and fire season. FRIs (8-26 years; 1980-2010) were comparable to those elsewhere in the CFK and appeared to be shorter in the eastern Tsitsikamma than in the western Outeniqua halves of the study area. Proteaceae juvenile periods (4-9 years) and postfire recruitment success suggested that for biodiversity conservation purposes, FRIs should be ≥ 9 years in eastern coastal fynbos. Collectively, findings on the seasonality of actual fires and the seasonality of fire danger weather, lightning and post-fire proteoid recruitment suggested that fires in eastern coastal fynbos are not limited to any particular season. We articulated these findings into ecological thresholds pertaining to the different elements of the fire regime in eastern coastal fynbos, to guide adaptive management of fire in the Garden Route National Park and elsewhere in the region.
Conservation implications: Wildfires are likely to remain dominant in eastern coastal fynbos, whilst large-scale implementation of prescribed burning is unattainable. Fires occurring in any season are not a reason for concern, although other constraints remain: the need for sufficient fire intensity, safety requirements, and integration of fire and invasive alien plant management.
Plant communities along the Eerste River, Western Cape, South Africa : community descriptions and implications for restoration : checklistSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –14 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1099More Less
Riparian plant communities fulfil many functions, including the provision of corridors linking protected areas and other zones of high conservation value. These habitats across much of South Africa's Cape Floristic Region, especially in the lowlands, have been heavily impacted and degraded by human activities. There is increasing interest in the restoration of degraded riparian zones and the ecosystem services they provide to enhance the conservation value of landscapes. Previous studies of riparian vegetation in the Cape Floristic Region focused on pristine headwater systems, and little is known about human-impacted communities that make up most of the riparian vegetation in downstream areas. More information is needed on the composition of these plant communities to establish a baseline for management intervention. The riparian zone of the Eerste River in South Africa's Western Cape province provides a good opportunity to study the features of riparian vegetation along the entire gradient, from pristine vegetation in a protected area through different levels of human mediated degradation. Riparian vegetation was surveyed in 150 plots along the entire length of the Eerste River (ca. 40 km). Data were analysed using the vegetation classification and analysis software package JUICE. Final groupings were plotted onto a two-dimensional detrended correspondence analysis plane to check the position of the communities in the reduced multidimensional space. Ten distinct plant communities were identified, including several novel communities dominated by alien plant species. Descriptions of each plant community are presented. Diagnostic, constant and dominant species are listed and the major structural and ecological characteristics of each community are described.
Conservation implications: Major changes to hydrological and soil properties, nutrient dynamics and disturbance regimes and plant species composition along sections of the riparian zone mean that restoration of many of these habitats to their historic condition is not feasible. However, several native plant species that provide key ecosystem services persist in and adjacent to transformed communities, offering substantial opportunities for restoration to achieve certain goals.
Grassland communities of urban open spaces in Bloemfontein, Free State, South Africa : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –8 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1075More Less
Natural vegetation in urban environments is greatly impacted by human activities and it is in constant threat of degradation and destruction as a result of urbanisation. This vegetation,although fragmented, serves an important ecological function and needs to be properly managed and conserved. Studies on urban vegetation are lacking in South Africa, with only a handful having been carried out since the end of the last century. This study was initiated to identify, classify and describe the grassland communities of the urban open spaces in Bloemfontein. Relevés were compiled in 61 sample plots, where species present and habitat information were recorded. Care was taken to restrict sample plots to vegetation in pristine condition, wherever possible, and severely degraded stands were avoided. A two-way indicator species analysis (TWINSPAN) classification, refined by Braun-Blanquet procedures, revealed two distinct major communities, seven communities and four sub-communities. Both detrended and canonical correspondence analyses indicated the vegetation units to be associated with soil texture and pH, although biotic factors such as overgrazing, burning and mowing also influence the composition of the vegetation. The proper management and conservation of urban open spaces requires in-depth knowledge of the spatial distribution, floristic, structural and functional compositions within the major vegetation types in this environment. The present study further contributed towards formulating ways for the proper management, utilisation and functioning of the open spaces within the Bloemfontein area.
Conservation implications: The Grassland Biome of South Africa is poorly conserved, mainly because of its status as an agricultural hub of the country. The preservation of natural and semi-natural forms of urban vegetation is important because such vegetation, although often disturbed and degraded, could form dispersal corridors between peri-urban and rural vegetation.
Plant nematodes in South Africa 11 : checklist of plant nematodes of the protected areas of KwaZulu-Natal : checklistSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –2 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1086More Less
Nematodes are some of the most abundant soil organisms and are an essential part of soil ecology. These organisms are used as indicator organisms and can be linked to soil health. Biological collections contain vast amounts of data, with the National Collection of Nematodes housed at the Plant Protection Research Institute, Agricultural Research Council being no different. During the digitising of the collection a number of unpublished records of plant nematodes reported from protected areas in KwaZulu-Natal were found in the South African Plant-Parasitic Nematode Survey database. A total of 222 plant nematode species belonging to 39 genera were reported from the province, with only 94 of these species reported from the protected areas and 172 and 159 species reported from uncultivated (outside the protected areas) and cultivated areas, respectively. Only nine species, Criconema silvum, Criconema talanum, Helicotylenchus marethae, Ogma dracomontanum, Ogma louisi, Ogma ueckermanni, Paralongidorus deborae, Trichodorus rinae and Xiphinemella marinade were described from protected areas, whilst O. dracomontanum, P. deborae and T. rinae were subsequently also reported from other provinces.
Conservation implications: A higher degree of diversity of nematodes was observed in the unprotected areas of the province. The observation suggests that nematode fauna, and by implication also other invertebrates, are not adequately protected
Population ecology of vervet monkeys in a high latitude, semi-arid riparian woodland : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –9 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1078More Less
Narrow riparian woodlands along non-perennial streams have made it possible for vervet monkeys to penetrate the semi-arid karoo ecosystem of South Africa, whilst artificial water points have more recently allowed these populations to colonize much more marginal habitat away from natural water sources. In order to better understand the sequelae of life in these narrow, linear woodlands for historically 'natural' populations and to test the prediction that they are ecologically stressed, we determined the size of troops in relation to their reliance on natural and artificial water sources and collected detailed data from two river-centred troops on activity, diet and ranging behaviour over an annual cycle. In comparison to other populations, our data indicate that river-centred troops in the karoo were distinctive primarily both for their large group sizes and, consequently, their large adult cohorts, and in the extent of home range overlap in what is regarded as a territorial species. Whilst large group size carried the corollary of increased day journey length and longer estimated interbirth intervals, there was little other indication of the effects of ecological stress on factors such as body weight and foraging effort. We argue that this was a consequence of the high density of Acacia karroo, which accounted for a third of annual foraging effort in what was a relatively depauperate floristic habitat. We ascribed the large group size and home range overlap to constraints on group fission.
Conservation implications: The distribution of group sizes, sampled appropriately across habitats within a conservation area, will be of more relevance to management than average values, which may be nothing more than a statistical artefact, especially when troop sizes are bimodally distributed.
Kruger National Park research supersites : establishing long-term research sites for cross-disciplinary, multiscaled learning : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –7 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1107More Less
Researchers interested in studying the effects of fire or herbivory in the Kruger National Park (KNP) often focus their research activities on the experimental burn plots or herbivore exclosure camps, respectively. These are manipulated sites that apply treatments, for example annual fires or total exclusion of fire and herbivores. However, many projects aim to study or monitor patterns and processes emerging under non-manipulated conditions, typically at sites with contrasting geologies and rainfall. Yet, these sites are usually selected in a haphazard and uncoordinated manner for different projects and, as a consequence, it is often not possible to integrate datasets and knowledge. An alternative to the ever-increasing number of unrelated sites scattered across the park are the 'KNP research supersites' which have been earmarked to geographically focus future research effort, acting as data-rich, long-term sites for monitoring and research. In this paper, we introduced the four recently established KNP research supersites, which cover the rainfall gradient and geological contrast of the KNP, presenting their rationale, selection criteria and location, along with existing datasets that describe their herbaceous biomass, woody cover, phenology, fire history, levels of herbivory. Additional site-specific datasets, which are already available, or which are in preparation, were outlined together with details for assessing these open-source datasets online.
Conservation implications: The KNP research supersites will become increasingly used for research, monitoring and remote-sensing calibration and ground-truthing purposes. Scientists are encouraged to gain from, and contribute towards, these sites, which will facilitate long-term data collection, data-sharing and co-learning and, ultimately, lead to a more integrated, multiscaled and multitemporal understanding of savannahs.
Ecology of the plant-dwelling spiders (Arachnida : Araneae) of the Erfenis dam nature reserve, South Africa : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –9 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1113More Less
As part of the South African National Survey of Arachnida in the Grassland Biome, foliage-dwelling and grass-dwelling spiders (Arachnida: Araneae) were collected in the Erfenis Dam Nature Reserve in the central Free State Province from November 2005 to August 2007. Foliage-dwelling spiders were collected from three common tree or shrub species (Acacia karroo, Searsia ciliate and Searsia lancea) and grass-dwellers from four contrasting grasslands (uniform Themeda triandra/, mixed, weedy and woodland grasslands). From the grass layer, 1649 spiders were collected, representing 15 families and 82 species, whilst 496 tree-dwelling spiders were collected that represented 17 families and 52 species. There was some overlap in the fauna of the two strata, resulting in a total of 108 species from 18 families being collected. The Araneidae, Philodromidae, Salticidae and Thomisidae were consistently the most abundant in all grassland types and tree species, although Salticidae were scarce on A. karroo. Assemblage analysis indicates high similarity and overlap in the fauna of the four grassland types, suggesting that the structural complexity of grasslands has a limited effect on species composition. In contrast, the foliage-dwelling assemblages were more distinct, with only some overlap between the faunas of S. ciliate and A. karroo, suggesting a stronger vegetation structural effect in shaping arboreal spider assemblages. The isolation of trees and shrubs within the extensive grassy habitat may contribute to the more unique fauna and lower species richness of the woody vegetation.
Conservation implications: This study uncovered a rich diversity of plant-dwelling spiders from central South Africa. Grassland faunas show considerable temporal variation and some variability in microhabitat preferences, and sampling protocols should take this into account when spiders are considered in management plans and biodiversity surveys in reserves and private land.
The use of population viability analysis to identify possible factors contributing to the decline of a rare ungulate population in south-eastern Zimbabwe : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –9 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1081More Less
Populations that are vulnerable to decline are of particular concern to wildlife managers and uncovering the mechanisms responsible for downward trends is a crucial step towards developing future viable populations. The aims of this study were to better understand the mechanisms behind the historic decline of the sable antelope, Hippotragus niger, population at the Malilangwe Wildlife Reserve (MWR), to assess its future viability and to use this analysis to determine key areas of breakdown in population growth and link these to potential limiting factors. VORTEX, a population viability model was used to assess the future viability of the sable antelope population and a sensitivity analysis was applied to identify the key areas of breakdown in growth. The sable population is currently viable, but remains highly vulnerable to changes in adult female survival, a factor which had the greatest influence on overall population fitness. Lion predation, impacting on the adult segment of the population, appeared to be the main factor responsible for the historic decline at the MWR.
Conservation implications: Sable generally occur at low densities in the lowveld region of Zimbabwe and, as such, populations are vulnerable to increases in mortality rates. The role of lions in driving the decline at the MWR suggests a need to control their numbers and develop prey refuges through improved management of artificial water.
Source: Koedoe : African Protected Area Conservation and Science 55, pp 1 –5 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1096More Less
Resource harvesting is permissible within South African protected areas under certain conditions as part of benefit sharing that seeks to strengthen relationships with communities living adjacent to parks. However, not all resource use is authorised and little is currently known about what is harvested, or the extent and impacts of harvesting in parks. This limits capacity to monitor and set the boundaries for such use. This paper provides a checklist of resources harvested within each of 19 national parks managed by South African National Parks. Data were gathered by means of a question-based survey of park staff. A database detailing the parks from which each resource was harvested and its purpose(s) was compiled, representing the most comprehensive list of resources harvested from parks to date. A total of 382 harvested biological and abiotic resources (284 terrestrial and 98 aquatic), used for a wide range of purposes, were identified across parks. Many of the resources, especially animals (96%), were harvested destructively. The strongest motivation for harvest was subsistence, although most resources were also used for financial gain through informal business. Although current data are not sufficient to determine harvest sustainability for most resources, better data and increased awareness of resource use activities will enable future research to this end.
Conservation implications:The checklist of harvested resources provides critical baseline data for parks, which will facilitate assessment of park-specific priorities for research, monitoring and management action.
Virgilia divaricate may facilitate forest expansion in the afrotemperate forests of the southern Cape, South Africa : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –8 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1128More Less
Virgilia divaricata is a fast-growing nitrogen-fixing tree species often found on the margins of forest in the southern Cape of South Africa and is particularly abundant after fire. However, V. divaricata may invade fynbos even in the absence of fire and it has been described as a forest precursor. We investigated whether V. divaricata enriches soil fertility after its invasion into fynbos areas adjacent to forests. We measured soil organic carbon and soil nutrients at four sites. At each site, three vegetation types (forest, V. divaricata and fynbos) were examined on the same soil type and at the same elevation. Our results showed that, on average, soils taken from V. divaricata stands had higher nitrogen and phosphorus values than the adjacent fynbos soils, with either lower or similar values to the adjacent forest soils. Higher soil fertility under V. divaricata, together with their shading effect, may create conditions favourable for shade-loving forest species dependent on an efficient nutrient cycle in the topsoil layers, and less favourable for shade-hating fynbos species, which are generally adapted to low soil fertility. We suggest that the restoration of the nutrient cycle found in association with forest may be accelerated under V. divaricata compared with other forest precursor species, which has important consequences for the use of V. divaricata in ecosystem restoration.
Conservation implications: Alien plantations in the Outeniqua Mountains are being phased out and the areas are being incorporated into the Garden Route National Park. Fynbos areas are increasingly being invaded by forest and thicket species owing to fire suppression in lower-lying areas. An improved understanding of the fynbos-forest boundary dynamics will aid in efficient management and restoration of these ecosystems.
Guidelines for phytosociological classifications and descriptions of vegetation in southern Africa : checklistSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –10 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1103More Less
Changes in the environment are first observed in changes in the vegetation. Vegetation survey, classification and mapping form the basis on which informed and scientifically defendable decisions on the environment can be taken. The classification and mapping of vegetation is one of the most widely used tools for interpreting complex ecosystems. By identifying different plant communities we are essentially identifying different ecosystems at a particular hierarchical level. Phytosociologists in Europe have been involved in such studies following, in particular, the Braun-Blanquet approach since the early 1900s. In South Africa, such studies were undertaken on a limited basis from the early 1970s and have since then steadily increased. The surveying of the enormous diversity of South African vegetation is one of the objectives of phytosociological studies. The demand for such data has steadily increased over the past few years to guide conservation policies, biodiversity studies and ecosystem management. In South Africa, numerous publications on the vegetation of conservation and other areas in the different biomes have been produced over the last few decades. However, vegetation scientists in South Africa experience unique problems. The purpose of this article is therefore to provide an overview of the history and the specific focus of phytosociological studies in South Africa and to recommend minimum requirements and methods to be followed when conducting such studies. It is believed that the incorporation of these requirements will result in scientifically justifiable research of high quality by phytosociologists in South Africa.
Conservation implications : Effective conservation cannot be obtained without a thorough knowledge of the ecosystems present in an area. Consistent vegetation classifications and descriptions form the basis of conservation and monitoring exercises to maintain biodiversity. The incorporation of these guidelines and requirements will facilitate quality phytosociological research in South Africa.
Will woody plant encroachment impact the visitor experience and economy of conservation areas? : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –9 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1106More Less
Woody plant encroachment into savannas is a globally prevalent phenomenon and impacts ecosystem goods and services such as biodiversity, carbon storage, nutrient cycling, grazing and hydrology. The direct ecological and economic consequences for rangelands have been fairly well studied, but, to our knowledge, the economic impact on conservation efforts has not been investigated. African savannas are important as conservation areas because they support large numbers of the world's remaining megafauna. This study used visitor surveys and long-term mammal distribution data to investigate how an increase in tree density might affect the visibility of animals in a conservation area, which could reduce the satisfaction of visitors to the area. We found that apparent herd sizes and density of animals were much reduced in woody areas, suggesting that visibility is negatively impacted. Visitor surveys determined that a large fraction (almost half) of potential future visitors to the park may be lost if animals became more difficult to see and that the majority of these would be the higher-spending visitors. Responses differed depending on the origin of visitors, with international visitors being more interested in seeing animals, whilst local visitors were more content with just being away from the city. The results suggest that woody plant encroachment may have significant impacts on visitor numbers to savanna conservation areas, whilst animal numbers and densities may also be significantly impacted.
Conservation implications : The results pointed to potentially significant economic consequences for conservation efforts as visitors become less satisfied with their experience. Perceptions of visitors are important for management decisions as park fees contribute significantly to conservation efforts. This could ultimately result in a reduced capacity for African conservation areas to conserve their biodiversity effectively. The results suggest that management may need to re-evaluate their approach to controlling woody plant encroachment.
Classification and mapping of the composition and structure of dry woodland and savanna in the eastern Okavango Delta : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –8 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1100More Less
The dry woodland and savanna regions of the Okavango Delta form a transition zone between the Okavango Swamps and the Kalahari Desert and have been largely overlooked in terms of vegetation classification and mapping. This study focused on the species composition and height structure of this vegetation, with the aim of identifying vegetation classes and providing a vegetation map accompanied by quantitative data. Two hundred and fifty-six plots (50 m x 50 m) were sampled and species cover abundance, total cover and structural composition were recorded. The plots were classified using agglomerative, hierarchical cluster analysis using group means and Bray-Curtis similarity and groups described using indicator species analysis. In total, 23 woody species and 28 grass species were recorded. Acacia erioloba and Colophospermum mopane were the most common woody species, whilst Urochloa mossambicensis, Panicum maximum, Dactyloctenium gigantium and Eragrostis lehmanniana were the most widespread grasses. Eleven vegetation types were identified, with the most widespread being Short mixed mopane woodland, Tall mopane woodland and Tall mixed mopane woodland, covering 288.73 km2 (28%), 209.14 km2 (20%) and 173.30 km2 (17%) of the area, respectively. Despite their extensive area, these three vegetation types were the least species-rich, whilst Palm thornveld, Short mixed broadleaf woodland and Open mixed Acacia woodland were the most taxonomically variable. By contrast, Closed mixed Acacia woodland and Closed Acacia-Combretum woodland had the most limited distribution, accounting for less than 1% of the mapped area each.
Conservation implications : The dry woodland and savanna vegetation of the Okavango Delta comprises a much wider suite of plant communities than the Acacia-dominated and Mopane-dominated classifications often used. This classification provided a more detailed understanding of this vegetation and essential background information for monitoring, management and research.
Is the present Brackenridgea Nature Reserve large enough to ensure the survival of Brackenridgea zanguebarica Oliv.? : short communicationSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –5 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1072More Less
The Brackenridgea Nature Reserve is a 110 ha protected area established by the provincial Limpopo Department of Economic Development, Environment and Tourism as a way of protecting the population of Brackenridgea zanguebarica, a species classified as critically endangered in South Africa. In the whole of South Africa, the species is found in only one small area around Thengwe-Mafukani in Venda. It is threatened with extirpation due to high demand for its medicinal bark. This study investigated the adequacy of the reserve to conserve the species using a method established in 2001 by Burgman et al. This method involves 12 steps to quantify the risk of the decline or possible extinction of the species and takes current human activities, disturbances and the viability of the population into consideration for setting a conservation target. From the results, it was clear that more area is needed for the current population to survive beyond 50 years. Assuming the status quo, it will require 410 ha to maintain the population, whereas a 50% reduction in human-related activities, such as cultivation, harvesting and livestock grazing, will lower the required potential habitat to 203 ha and a conservation option, which allows for bark harvesting, will require 179 ha.
Conservation implications : The results of this study will have conservation implication on management of viable species population within a nature reserve. It will require managers to take into consideration the reserve size in relation to potential habitats for the development of species under their management.
Long-term stability of grazing lawns in a small protected area, the Mountain Zebra National Park : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –7 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1108More Less
We examined a heavily grazed plant community dominated by creeping grass species with the aim of, (1) determining its response to the exclusion of grazing and (2) its long-term persistence. This plant community was particularly favoured by wild ungulate species that prefer short grasses - blesbok (Damaliscus dorcas phillipsi), springbok (Antidorcas marsupialis) and black wildebeest (Connochaetes gnou). Exclusion of grazing by large herbivores by means of fencing resulted in the virtual disappearance of the creeping grasses and their replacement by tall tufted species. On plots that remained unfenced, the plant species composition was found to be little changed after an interval of more than 20 years. The number large stock unit equivalents (LSU) per ha carried by the plant community was used as a proxy for grazing intensity. Monitored for approximately 2 years at the start of the study, LSU per ha was found to greatly exceed levels recommended for commercial livestock production. This plant community conforms to a recently published definition of a grazing lawn, in that intense grazing promotes palatable, grazing-tolerant grass species.
Conservation implications : The positive association between grazers and grazing-tolerant grass species evidently persisted for more than 20 years and there was no evidence of an increase in abundance of unpalatable plant species. Despite the small size of the park, which limited the extent of large herbivore movements, localised heavy grazing did not lead to range degradation.
How objective are protected area management effectiveness assessments? A case study from the iSimangaliso Wetland Park : original researchAuthor Clinton CarbuttSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –8 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1110More Less
The assessment of protected area management effectiveness was developed out of a genuine desire to improve the way protected areas are managed and reported on, in relation to a formalised set of conservation objectives. For monitoring and reporting purposes, a number of participatory methods of rapidly assessing management effectiveness were developed. Most rapid assessment methods rely on scoring a range of protected area-related activities against an objective set of criteria documented in a formal questionnaire. This study evaluated the results of two applications of the same management effectiveness assessment tool applied to the same protected area, namely the iSimangaliso Wetland Park, South Africa. The manner in which the assessments were undertaken differed considerably and, not unexpectedly, so did the results, with the national assessment scoring significantly higher than the provincial assessment. Therefore, a further aim was to evaluate the operating conditions applied to each assessment, with a view to determining which assessment was more closely aligned with best practice and hence which score was more credible. The application of the tool differed mainly with respect to the level of spatial detail entered into for the evaluation, the depth and breadth of the management hierarchy that was consulted, the time in which the assessment was undertaken and the degree of peer review applied. Disparate scores such as those obtained in the assessments documented here are likely to bring the discipline of management effectiveness assessment into disrepute unless an acceptable and standardised set of operating procedures is developed and adopted. Recommendations for such a set of 'indispensable constants' were made in this article to ensure that management effectiveness assessments remain robust and reputable, thereby ensuring an honest picture of what is happening on the ground.
Conservation implications : We proposed that standard operating procedures should be in place when protected area management effectiveness assessments are undertaken, in order for the results to be credible. This involves ensuring that the right people participate and that each participant is allowed sufficient time to peer review each other.
The home range of a recently established group of Southern ground-hornbill (Bucorvus leadbeateri) in the Limpopo Valley, South Africa : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –8 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1135More Less
Little is known about Southern ground-hornbill (SGH) population ecology outside of large, formally protected areas where the largest declines in numbers have been recorded. The SGH has started re-colonising, establishing group territories and breeding successfully in the Limpopo Valley on the northern border of South Africa, following localised extinction from the 1950s to the 1970s. A group of SGH was monitored over a period of 14 months by means of radio telemetry across privately owned land in order to investigate their seasonal habitat movements in this semi-arid, predominantly livestock-based environment. We also investigated seasonal fluctuations in invertebrate prevalence, as an indication of food availability and its influence on seasonal SGH group movements and foraging activity patterns. There was a clear increase in food availability during the summer rainfall period allowing the group to forage over a wider area, whilst winter foraging remained localised within their range. Kernel home range analysis indicated a marked difference in size between the summer (13 409 ha) and winter (5280 ha) home ranges, with an overall home range of 19 372 ha, which is approximately double that of home ranges recorded that fall within formally and informally protected reserves. In this article, we proposed that food availability is the driving force for home range size and seasonal activity patterns in a semi-arid livestock-ranching habitat.
Conservation implications : The Limpopo Valley SGH population is one of the most significant outside protected areas in South Africa. This population is especially vulnerable to threats such as poisoning, persecution for window breaking and drought, as shown by their near extirpation from the area. Conservation efforts need to focus on awareness amongst local farmers, provision of artificial nests and continued monitoring of groups.
Monitoring of the eggs of the Karkloof blue butterfly, Orachrysops ariadne, for its conservation management : original researchSource: Koedoe : African Protected Area Conservation and Science 55, pp 1 –11 (2013) http://dx.doi.org/10.4102/koedoe.v55i1.1150More Less
The Endangered Orachrysops ariadne (Butler 1898) (Karkloof blue butterfly) is endemic to the Endangered Moist Midlands Grassland in KwaZulu-Natal, South Africa, and is extant at four sites. The results from the monitoring of the eggs laid by O. ariadne in a grassland area that is frequently burnt by poor rural people to ensure that palatable grass is available to their livestock, suggested the implementation of management interventions (fencing and firebreak burning) to prevent the local extinction of the butterfly. The number of eggs at the monitoring site declined dramatically between 2002 and 2003 and fluctuated after the management interventions were initiated properly in 2008, but had nearly reached the target number of 250 by 2013. An index count method for the monitoring of O. ariadne eggs at the other three known colonies, where plant invasion rather than uncontrolled burning is a major threat, was developed and shown to be efficient with regard to time relative to the number of eggs sampled. The host ant Camponotus natalensis (F. Smith 1858) (Natal sugar ant) was found to be present in all the host-plant patches at one colony site, indicating that all host-plant patches are likely to be breeding areas for the butterfly. Invasive plant control at and appropriate burning of the habitat of O. ariadne should assist in ensuring the survival of these colonies.
Conservation implications : Adaptive monitoring and management of threatened endemic invertebrates and their habitats may be crucial for their continued survival. The development of efficient methods for the monitoring of such species is required where resources are limited, as threats to the species may cause sudden and irreversible declines in population size.