Search

Aloe reitzii var. reitzii is a summer-flowering (February–March) succulent, endemic to a restricted range within the heavily transformed grasslands of eastern South Africa. Floral structure and nectar properties suggest bird-pollination. This study investigated the temporal visitation events of birds to this aloe. Extensive camera observations during the 2017 flowering season (23 days) identified both specialist and generalist nectarivorous birds (n = four and five species respectively) as regular diurnal aloe visitors. Malachite Sunbirds (Nectarinia famosa) accounted for 49% of all visits, while Cape Weavers (Ploceus capensis) made up 41% of all visits; these species co-dominate visitation of the specialist and generalist avian feeding guilds respectively. In addition, visitation by each guild was separated temporally to some extent, with generalists mostly visiting early in the day, while specialists dominate afternoon visitation. Nectar volume (overall unbagged mean = 48.67 ± 4.70 µL) and concentration (overall unbagged mean = 10.68 ± 0.21% w/w) remains consistent throughout the day, and are within generalist nectar-feeding bird preferences, which may explain the abundance of Cape Weavers, despite floral morphological traits matching those of specialist nectar feeders. While many summer-flowering aloes are primarily insect- or sunbird-pollinated, Cape Weavers may be supplementing their diets with A. reitzii var. reitzii nectar, and potentially playing a crucial role in pollination.

Communal livestock grazing is expected to impact botanical composition and plant diversity of Drakensberg montane grasslands. Accordingly, a grazing gradient extending outward from kraals, and fence-line contrasts between communal rangeland and protected areas (Golden Gate Highlands National Park and Royal Natal National Park), were studied in the QwaQwa region of South Africa. Presence of a grazing gradient was confirmed by a decrease in the amount of cattle dung with increasing distance from kraals that was independent of altitude, solar radiation, slope, or soil physico-chemical properties. Canonical correspondence analysis confirmed thatgrazing intensity had a significant influence on botanical composition although most compositional variation was unexplained. Higher grazing intensities tended to negatively affect plant species richness and diversity, and the cover of perennial graminoids, but benefitted the abundance of dwarf shrubs and alien invasive species. Similar effects were apparent across each of the fence line contrasts. Despite a long history of livestock grazing, communal rangeland supported >320 indigenous species, illustrating some contribution to biodiversity conservation, but being compromised near kraals. An improved approach for study of the impacts of livestock grazing on plant diversity is suggested that would overcome the difficulties of assessing rare and threatened species using acommunity approach. Keywords: communal rangelands, fence line contrast, functional types, grazing gradients

Annual growth rings are absent in many long-lived grassland geoxyles. Thus, estimates of age for individuals are largely based on non-benchmarked assessments by experienced botanists. We wished to obtain a more precise estimate of age from the xylopodia of four geoxylic taxa (i.e. Berkheya insignis, Callilepis laureola, Protea simplex and Tephrosia kraussiana) growing in a Pondoland grassland, using both the gas proportional counting and Accelerated Mass Spectroscopy radiocarbon dating techniques. Plants sampled in 2008 fell within modern concentrations of carbon 14; therefore, radiocarbon dating generally yielded two ages for each plant, an older age (range: 45–51 years, mean=49, CV=3.6%) corresponding with the nuclear testing period, and a younger age (range: 10–29 years, mean=18, CV=35%), corresponding to the period after the Partial Nuclear Test Ban Treaty. Hence the older ages are much less variable than the younger ages. All plants had the older age estimate, and all but two had the younger age estimate. In addition, two plants each, had two similar older age estimates. P. simplex plants were 16, 24, 27 and 29, or 45, 46–49, 47 and 49 years, T. kraussiana 13, 15 and 16, or 50 and two of 51 years, C. laureola 12, 15 and 21, or 49–50 and two of 50 years and B. insignis were 10, or 49, 50 and 51 years old. Growth rings were not visible with the naked eye. However, using stereomicroscopy, ring-like patterns were visible to some extent at 7X magnification for B. insignis, P. simplex and T. kraussiana, but not C. laureola. Counts of these structures were much lower than the younger 14C dates, and hence are unlikely to be annual rings. Despite the ambiguity of multiple ages, these estimates are a useful starting point or benchmark for future empirical investigations of age for forbs with no clear annual rings. Most studies have used radiocarbon dating to estimate the age of woody tree stem tissue, whereas this study is one of few to measure the age of below-ground modern tissues of South African forbs. Suggestions for further refinement during collection and processing of geophytic sample material are made based on lessons learned from this investigation.

African termites are classified into five distinct families, Termitidae, Rhinotermitidae, Hodotermitidae, Termopsidae and Kalotermitidae. Termites are undoubtedly one of the key ecosystem engineers...

Background and AimsFine-scale spatial patterns of the seedlings of co-occurring species reveal the relative success of reproduction and dispersal and may help interpret coexistence patterns of adult plants. To understand whether postfire community dynamics are controlled by mathematical, biological or environmental factors, we documented seedling–adult (putative parent) distances for a range of co-occurring species. We hypothesized that nearest-seedling-to-adult distances should be a function of the distance between the closest conspecific seedlings, closest inter-adult distances and seedling-to-parent ratios, and also that these should scale up in a consistent way from all individuals, to within and between species and finally between functional types (FTs).MethodsWe assessed seedling–adult, seedling–seedling and adult–adult distances for 19 co-occurring shrub species 10 months after fire in a species-rich shrubland in south-western Australia. Species were categorized into 2 × 2 FTs: those that are killed by fire [non-(re)sprouters] vs. those that survive (resprouters) in nine taxonomically matched pairs, and those that disperse their seeds prefire (geosporous) vs. those that disperse their seeds postfire (serotinous).Key ResultsFor the total data set and means for all species, seedling–adult distance was essentially a mathematical phenomenon, and correlated positively with seedling–seedling distance and adult–adult distance, and inversely with seedlings per adult. Among the four FTs, seedling–adult distance was shortest for geosporous non-sprouters and widest for serotinous resprouters. Why adults that produce few seedlings (resprouters) should be further away from them defies a simple mathematical or biological explanation at present. Ecologically, however, it is adaptive: the closest seedling was usually under the (now incinerated) parent crown of non-sprouters whereas those of resprouters were on average four times further away.ConclusionsOur study highlights the value of recognizing four reproductive syndromes within fire-prone vegetation, and shows how these are characterized by marked differences in their seedling–adult spatial relations that serve to enhance biodiversity of the community.

More frequent and intense climate hazards, a predicted outcome of climate change, are likely to threaten existing livelihoods in rural communities, undermining households’ adaptive capacity. To support households’ efforts to manage and reduce this risk, there is a need to better understand the heterogeneity of risk within and between communities. The Intergovernmental Panel on Climate Change revised their climate vulnerability framework to incorporate the concept of risk. This study contributes toward the operationalization of this updated framework by applying a recognized methodology to the analysis of the climate-related risk of rural households. Using a mixed-method approach, including a cluster analysis, it determined and assessed archetypical patterns of household risk. The approach was applied to 170 households in two villages, in different agroecological zones, in the Vhembe District Municipality of South Africa’s Limpopo Province. Six archetypical climate-risk profiles were identified based on differences in the core components of risk, namely, the experience of climate hazards, the degree of exposure and vulnerability, and the associated impacts. The method’s application is illustrated by interpreting the six profiles, with possible adaptation pathways suggested for each. The archetypes show how climate-related risk varies according to households’ livelihood strategies and capital endowments. There are clear site-related distinctions between the risk profiles; however, the age of the household and the gender of the household head also differentiate the profiles. These different profiles suggest the need for adaptation responses that account for these site-related differences, while still recognizing the heterogeneity of risk at the village level.

QUESTIONS: The degree to which renosterveld shrublands are fire‐dependent is currently unclear. To address this issue, the following questions were asked: (1) does smoke stimulate germination of soil‐stored seeds in renosterveld; (2) does recently‐burned renosterveld display changed composition and higher diversity than unburned vegetation; and (3) how do the species compositions of renosterveld soil seed banks and standing vegetation compare? LOCATION: Swartland, Cape Floristic Region, South Africa. METHODS: Soil seed bank samples from a north‐ and south‐facing slope were smoke‐treated and germinated to test for smoke‐stimulated germination. Burned standing vegetation was surveyed 16 months post‐fire, as was unburned vegetation on the same slopes. Seed bank species richness and density were compared between smoke‐treated and untreated samples within and between slopes. Burned and unburned standing vegetation were compared within and between slopes in terms of species richness, abundance and aerial cover. Compositional similarity of the seed banks and standing vegetation was assessed. RESULTS: Seed banks were dominated by annuals and graminoids. Smoke treatment had no effect, except for driving significantly higher species richness and seedling density in south‐facing slope perennial shrubs. Species richness and seedling density were significantly higher in seed banks on the south‐facing slope compared to the north‐facing slope. Burned standing vegetation exhibited significantly higher diversity than unburned vegetation. Annuals and graminoids displayed significantly higher species richness and aerial cover in burned renosterveld. The north‐facing slope contained less than half the number of species/m² compared to the south‐facing slope. The seed banks and standing vegetation showed low to intermediate similarity (Sorensen = 31%–53%), but grouped close together on an NMDS plot, suggesting intermediate similarity overall. CONCLUSIONS: Elevated germination of perennial shrubs in smoke‐treated seed bank samples and increased diversity of post‐fire standing vegetation suggest the renosterveld in this study shows elements of a fire‐driven system. Certain species only recruited in burned sites, suggesting fire‐stimulated germination. Aspect had a major influence on plant community composition, with the mesic south‐facing slope being more diverse than the xeric north‐facing slope. The similarity between the seed banks and standing vegetation was higher than previously shown for renosterveld, and appears to be higher than for fynbos.

Collective properties of biodiversity, such as beta diversity, are suggested as complementary measures of species richness to guide the prioritisation and selection of important biodiversity areas in regional conservation planning. We assessed variation in the rate of plant species turnover along and between environmental gradients in KwaZulu-Natal, South Africa using generalised dissimilarity modelling, in order to map landscape levels of floristic beta diversity. Our dataset consisted of 434 plots (1000 m2) containing 997 grassland and savanna matrix species. Our model explained 79 % of the null deviance observed in floristic dissimilarities. Variable rates of turnover existed along the major environmental gradients of mean annual temperature, median rainfall in February, and soil cation exchange capacity, as well as along gradients of geographical distance. Beta diversity was highest in relatively warm, drier summer regions and on dystrophic soils. Areas of high beta diversity identify areas that should be included in conservation plans to maximise representation of diversity and highlight areas best suited to protected area expansion. Biome transition areas in high beta diversity areas may be susceptible to climate variability. Including beta diversity turnover rates in regional conservation plans will help to preserve evolutionary and ecological processes that create and maintain diversity.

Underprivileged communities rely on beneficial plants for medicinal and cultural purposes as well as income generation. They are marginalised by land use planners, politicians and municipalities, resulting in biased integrated development and increased poverty. A case in point, is the Critically Endangered Woodbush Granite Grassland (WGG) in Limpopo Province, South Africa. The WGG has high plant biodiversity (661 species in 192 ha), which includes 18 Red Listed taxa and 36 taxa protected by existing legislation. Although 18% of the plant species have medicinal properties and the area is a source of plants used for medicine and hand brushes, this is the first ethnobotanical study to be undertaken here. Structured interview schedules were conducted with 54 people who were using plants from the area, and a list of the top 20 medicinal plants was compiled. Respondents raised concerns regarding the impact of fire management and 69% of traditional healers noted increasing difficulty in finding useful pl...

Investigations into arthropod–aloe associations are focused mostly on aloe pollination and on aloe pests, while little is known about other ecological aspects of these associations. During a broader ecological study on the summer-flowering grassland endemic Aloe lettyae, we documented evidence of two arachnid–aloe interactions and 13 insect taxa occurring on or in parts of A. lettyae plants (n = 1084) in a representative sample of seven A. lettyae populations. Our data suggest that, of the insects observed, only honeybees play a part in A. lettyae pollination, while the other insect species were either visiting or feeding on A. lettyae reproductive plant parts. This paper presents additional records of an herbivorous insect–aloe interaction for the cerambycid beetle Nemotragus helvolus and the drosophilid fly Apenthecia cf. crassiseta, and documents the parasitoid wasp Afrostilba sp. associated with the latter.

Wild foods contribute towards the food security of an estimated one billion people. In light of expectations of the contribution of wild foods to sustainable and climate-resilient livelihoods and widespread evidence of their consumption, their contribution to households’ diets requires a more nuanced understanding, specifically with respect to their safety net function during food shortages. Data were collected from two villages in Venda, South Africa, selected due to differences in mean annual precipitation. Semi-structured interviews were administered to 170 households and a Participatory Rural Appraisal was conducted to assess the influence of multiple variables, including household characteristics and site, on wild food use. Household archetypes were defined based on the frequency of consumption in response to increasing food scarcity. Our findings suggest limitations to the safety net function of wild foods including seasonal fluctuations in availability and decreased availability during extreme events, with dependent households decreasing their consumption frequency in response to food scarcity. Given this potential poverty trap, further research is required, particularly in terms of when the safety net function of wild foods may be weak or detrimental to the livelihoods of the vulnerable.

There is growing demand for biogeographical landscape classifications and ecological maps that describe patterns of spatially co-varying biotic and abiotic ecosystem components. This demand is fuelled by increasing data availability and processing capacity, by institutional practices of land and water resource management and planning and by the growth of transdisciplinary science that requires the development of a shared conceptual framework through which to view landscape character and behaviour. Despite the widespread use of ecological maps, and the extent to which they have become embedded in institutional practice, policy and law, no standard approach to ecosystem mapping has emerged, such that there are many valid ways of mapping the same landscape. Consensus is possible only when there is agreement on the spatial entities to be mapped. We propose a way of defining such entities and identifying them in any given landscape. Landscapes are conceived in terms of a conceptual biophysical template that constrains a wide range of ecological processes at various hierarchical levels. The template is conceived as comprising co-evolved associations of soils, vegetation, topography and hydrology that form a dynamic mosaic characteristic of a particular topographic, climatic and geological context that is continually being shaped by many perturbations. We synthesise themes from vegetation, soil and river sciences, using hierarchy theory to frame a perspective that facilitates the definition of mappable landscape entities at three hierarchical levels of organisation. These entities are conceived as archetypal structural-functional units, with form and process linked in conceptual models that underpin each archetype. We describe how our approach has been used to map ecological entities in Kruger National Park, South Africa, showing how the proposed framework integrates key system components, providing transparent foundations for transdisciplinary approaches to landscape management and science.

Global climate change is having marked influences on species distributions, phenology and ecosystem composition and raises questions as to the effectiveness of current conservation strategies. Conservation planning has only recently begun to adequately account for dynamic threats such as climate change. We propose a method to incorporate climate-dynamic environmental domains, identified using specific environmental correlates of floristic composition, into conservation strategies, using the province of KwaZulu-Natal, South Africa as a case study. The environmental domains offer an approach to conservation that conserves diversity under current and future climates, recognising that the species constituting diversity may change through time. We mapped current locations of domains by identifying their positions in a multi-dimensional environmental space using a non-hierarchical iterative k-means clustering algorithm. Their future locations were explored using an ensemble of future climate scenarios. The HadCM2 and GFDL2.1 models represented the extreme ranges of the models. The magnitude of change in each environmental domain was calculated using Euclidean distances to determine areas of greatest and least stability for each future climate projection. Domains occurring in the savanna biome increase at the expense of domains occurring in the grassland biome, which has significant negative consequences for the species rich grasslands. The magnitude of change maps represents areas of changed climatic conditions or edaphic disjunctions. The HadCM2 model predicted the greatest overall magnitude of change across the province. Species with specific soil requirements may not be able to track changing climatic conditions. A vulnerability framework was developed that incorporated climatic stability and habitat intactness indices. The mean magnitude of change informed the potential speed of transition of domains between the vulnerability quadrants. The framework informs appropriate conservation actions to mitigate climate change impacts on biodiversity. The study explicitly links floristic pattern and climate variability and provides useful insights to facilitate conservation planning for climate change.

The edible stinkbug Encosternum delegorguei is an obscure commodity derived from the cuisine of at least five ethnic groups in three sub-Saharan African countries. Derisive names and the obnoxious stench produced by stinkbugs belie the fact that they are nutritious and, once the odorous alarm pheromone is removed, a high demand delicacy. Annually almost four tons of dry stinkbugs are harvested in South Africa’s dry season (May to August). Income from selling stinkbugs mainly benefits women in impoverished rural communities and is used to improve livelihoods. The cumulative impacts of overexploitation, unsustainable harvesting methods, increasing commercialisation and land transformation could threaten this cultural practice. Domestication of stinkbugs and use of the left over waste water from processing stinkbugs could add more value to this bio-resource and assist in the alleviation of poverty and hunger. This study reinforces recent United Nations reports where insects are depicted as an eco-friendly, nutritious food source with potential to contribute to global food security.

Conservation planning in the face of global change is still in its infancy. A suggested approach is to incorporate environmental gradients into conservation planning as they reflect the ecological and evolutionary processes generating and maintaining diversity. Our study provides a framework to identify the dominant environ- mental gradients determining floristic composition and pattern. Nonmetric multidimensional scaling was used on 2155 sampling plots in savanna and grassland habitat located across the province of KwaZulu-Natal, South Africa (94 697 km 2 ), a floristically rich region having steep environmental gradients, to determine the dominant gradients. Hierarchical cluster analysis was used to group similar plots which were then used in a Classification and Regression Tree analysis to determine the environmental delimiters of the identified vegetation clusters. Temperature-related variables were the strongest delimiters of floristic composition across the province, in particular mean annual temperature. Frost duration was the primary variable in the Classification and Regression Tree analysis with important implications for savanna/grassland dynamics. Soil properties (base, pH status) and moisture variables accounted for most of the variation for the second and third axes of floristic variation. Given that climatic and edaphic variables were well correlated with floristic composition, it is anticipated that a changing climate will have a marked influence on floristic composition. We predict warmer temperatures may facilitate the spread of frost sensitive savanna species into previously cooler, grassland areas. Species associated with specific soil types will not easily be able to move up the altitudinal gradient to cooler climes because geology is aligned in an approximately north-south direction compared with increasing altitude from east-west. Future conservation planning should take cognisance of these gradients which are surrogates for ecological and evolutionary processes promoting persistence.

Conservation managers are concerned about the impact that African elephants (Loxodonta africana) have on large tree species, necessitating the need for mitigation methods. Elephants actively avoid contact with African honeybees (Apis mellifera subsp. scutellata), staying clear of crop fields surrounded by beehive fence-lines and moving away from the sounds of swarming honeybees. Therefore, our objectives were to test whether the presence of beehives in trees influenced the likelihood of the tree receiving elephant impact, and compare these results to wire-netted (method used to prevent bark-stripping) and control (no treatment) trees. We selected a tree highly sought after by elephant, the marula tree (Sclerocarya birrea subsp. caffra), as our study species. We also assessed whether elephants avoided areas with marula trees containing beehives. Finally we provide a comparison of the financial costs of the beehive and wire-netting mitigation methods. We hung 50 active beehives in 50 trees, with 50 dummy beehives hung from branches on the opposite ends of each tree's main stem. We wire-netted another 50 trees and then assigned 50 trees as a control. Elephant impact on all 150 trees was measured prior to the addition of treatments and then post-treatment addition for 9 months. 54% of the control trees received some form of elephant impact, in comparison to 28% of the wire-netted trees and only 2% of the beehive trees. Wire-netting protected trees against bark-stripping but did not prevent elephants from breaking branches. Beehives proved to be the more effective mitigation method for elephant impact on large trees, although the presence of beehives did not prevent elephants from moving through the study site. The financial cost and maintenance required for the beehive mitigation method are greater than that of wire-netting, but the beehives can provide honey as an additive benefit on a small-scale usage level.

Savanna landscapes are vitally important in providing both ecological and economic services that sustain local livelihoods and national economies, particularly for sub-Saharan African countries whose economies are mainly agrarian. Development prospects in savanna landscapes are however dependent on actions to avoid and to slow or reverse degradation and that are aided with a clear understanding of trends in land use/cover changes, their causes and implications for conservation. We analysed land use/cover changes based on three Landsat satellite images (1984, 1995 and 2000/2001) and the influence of human utilization on the changes in an equatorial African savanna, central Uganda, for the period 1984–2000/2001. The land cover classification and change analysis clearly identified the dominant land cover types, revealing a severe reduction in woodland cover with dense woodlands decreasing by 64%, over a 17-year period. Consequently, medium woodland, open woodland and cultivation/settlements areas cover increased by 31%, 3% and 80%, respectively. The cover change analysis results were corroborated with interview results that also attributed the woodland cover loss to increasing commercial charcoal production, expanding livestock grazing, subsistence crop cultivation and an insecure land use tenure system. Indeed, the major land use types in the savanna are charcoal production, shifting crop cultivation and livestock rearing. The decreasing woody vegetation cover threatens the savanna's ability to continue providing ecosystems services to support the livelihoods of people who mainly depend on natural resources and are vulnerable to the impacts of climate change. Copyright © 2014 John Wiley & Sons, Ltd.

Management approaches taken in protected areas will affect their ability and effectiveness to conserve biodiversity. MalaMala (a concession within Sabi Sand Wildtuin, a private game reserve), and an adjacent area in the Kruger National Park (Kruger, statutory protected area) in South Africa provide a comparison of different types of conservation management. We measured three-dimensional woody vegetation structure, as an integral component of biodiversity, across 6200ha in the two reserves using a LiDAR (Light-Detection-and-Ranging) sensor. We compared how different management approaches in the two reserves affected woody structural diversity. Vertical canopy diversity was measured using: i) percent cover of woody vegetation extracted from LiDAR canopy height models, ii) a volumetric pixel (voxel) approach to extract 3D vertical canopy-height profiles; and iii) horizontal diversity using landscape metrics. MalaMala had higher vegetation density than Kruger in the 6m (2.7 times) height classes. This vegetation was in the form of larger, more cohesive patches as a result of the legacy of previous land-use (cattle ranching) and current management practices (bush clearing) and the recent increase in megaherbivores. Length of exposure to, and recent higher densities of, megaherbivores (particularly elephants) has altered the density of tall trees in the two reserves, thus affecting structural heterogeneity and associated habitat options for small-bodied vertebrates. These differences in vegetation structure are exacerbated by current management practices (e.g. bush-clearing and fire regime), with potential implications for faunal biodiversity conservation across a wide range of scales.

An accidental fire at a site where the reproductive behaviour of Glyceria maxima was being investigated provided an opportunity to measure its effect on G. maxima vegetative recruitment. The fire burned G. maxima growing along the water's edge and down to a water depth of 10 cm. Post-fire tiller densities in these zones were greater than identical sampling zones that were not burnt. Although fire appeared to favour G. maxima vegetative recruitment, more research is required with particular emphasis on integrating weed control methods with wetland restoration practices.

Biosphere Reserves attempt to align existing biodiversity conservation with sustainable resource use, specifically for improving socio-economic circumstances of resident communities. Typically, the Biosphere Reserve model is applied to an established landscape mosaic of existing land uses; these are often socio-ecological systems where strict environmental protection and community livelihoods are in conflict, and environmental degradation frequently accompanies "use". This raises challenges for successful implementation of the model, as the reality of the existing land-use mosaic undermines the theoretical aspirations of the Biosphere concept. This study focuses on the Kruger to Canyons Biosphere Reserve (K2C), South Africa; a socio-ecological landscape where formal conservation is juxtaposed against extensive impoverished rural communities. We focus on land-cover changes of the existing land-use mosaic (1993-2006), specifically selected land-cover classes identified as important for biodiversity conservation and local-level resource utilization. We discuss the implications of transformation for conservation, sustainable resource-use, and K2C's functioning as a "Biosphere Reserve". Spatially, changes radiated outward from the settlement expanse, with little regard for the theoretical land-use zonation of the Biosphere Reserve. Settlement growth tracked transport routes, transforming cohesive areas of communal-use rangelands. Given the interdependencies between the settlement population and local environmental resources, the Impacted Vegetation class expanded accordingly, fragmenting the Intact Vegetation class, and merging rangelands. This has serious implications for sustainability of communal harvesting areas, and further transformation of intact habitat. The distribution and magnitude of Intact Vegetation losses raise concerns around connectivity and edge effects, with long-term consequences for ecological integrity of remnant habitat, and K2C's existing network of protected areas.

The scarcity of indigenous trees on the Highveld of eastern South Africa is usually attributed to frost, fire and drainage, regardless of whether the soils are nutrient-poor (sourveld grasslands) or nutrient-rich (sweetveld grasslands). However, soil physicochemical properties—such as nutrient availability—are likely to affect vegetation structure by influencing competitive outcomes between herbaceous plants and tree seedlings. Woody cover in western southern Africa has been shown to be greatest on soils of intermediate nutrient status, decreasing on both nutrient-poor and nutrient-rich soils. We predicted – based on a theory of catabolic nutrient demand – that grassland–savanna boundaries on the Highveld would at least partly reflect soil properties. The soil contents of 22 elements, as well as pH and EC, were consequently analysed across 14 such boundaries in 6 provinces. Multivariate analysis showed that site location had the greatest influence on elemental content (r2 > 0.75, P 70% of elements analysed differed in one direction or the other at > 50% of study sites across the grassland–savanna boundary. Enrichment in grasslands (relative to savannas) was associated with sweetveld and impoverishment with sourveld, consistent with treeless grasslands occurring at both extremes of the nutrient continuum (nutrient-poor and -rich soils). An insight emerging from this study of the generally treeless Highveld is that the transition to savanna may coincide with an intermediate and potentially dystrophic section of the nutrient continuum where nutrients are imbalanced for grass growth. Because the static parameter of nutrient content may over- or underestimate nutrient availability, a next step in an investigation of the ultimate causes of treelessness would be to quantify rates of supply of different nutrients in treeless grasslands compared with savannas across grassland–savanna boundaries.

Copyright: 2013 Wiley Online Library. This is an ABSTRACT ONLY. The definitive version is published in Applied Vegetation Science, pp 1-13, doi: 10.1111/avsc.12048

The implementation gap between science, policy and practice has led to loss of biodiversity and ecosystem services throughout Africa and is described in a case study from Limpopo Province, South Africa. In 2006, the South African National Biodiversity Institute first highlighted the Woodbush Granite Grassland (WGG) in the Greater Tzaneen Local Municipality as the only Critically Endangered ecosystem in Limpopo Province. Five years later (2011), the Critically Endangered listing was published in the Government Gazette No. 34809. After repeated and sustained efforts for many years from volunteers of a local environmental group – currently known as the Friends of the Haenertsburg Grassland (FroHG) – in 2015 the intent to formally protect 126 ha was published in the Government Gazette No. 2609. Unfortunately, the proposed protected area accounts for only 66% of the largest remaining fragment of WGG, which excludes an important colony of medicinal plants. Considering that only 6% of the original extent of WGG remains in an untransformed state the whole fragment should be conserved. Non-alignment of municipal spatial priorities, as in the Haenertsburg town plan from 1896, to provincial and national environmental priorities has resulted in numerous incidents that have degraded what little remains of the WGG ecosystem. Failure of the provincial authorities to act timeously to enforce environmental regulations resulted in the FroHG successfully involving national authorities to stop illegal land occupation while another incident involving an illegal fence was resolved 9 years after erection. A strengthened relationship with Lepelle Northern Water has resulted in better planning of activities in relation to an existing pipeline. This case study shows various avenues available to environmental volunteer groups in South Africa and suggests that long-term lobbying can yield positive results.Conservation implications: Formal conservation of WGG through the intended nature reserve proclamation represents application of environmental legislation (notably Listing Notice 3, National Environmental Management Act 107 of 1998: Environmental Impact Assessment Regulations, 2014), scientific recommendations and policy. Better cooperation between provincial administration and FroHG will benefit the protection and management of WGG.

Aerosols play important roles in soil genesis and plant nutrition, at both local and intercontinental scales, by redistributing nutrients through the atmosphere. Aerosol capture by tree crowns is a possible mechanism by which trees significantly augment their nutrition, particularly in trace elements. Forests capture considerable amounts of aerosols relative to adjacent grasslands, but the extent to which aerosol capture occurs in small, scattered trees in savanna and the effect that such capture has on soil nutrients are unknown. We analyzed spatial variations in elemental concentration in topsoils near indigenous trees (

Sclerocarya birrea subsp. caffra (marula), a keystone large tree species in southern Africa and heavily utilized by people and herbivores, is declining at an unprecedented rate in the Kruger National Park (KNP), South Africa. Due to increasing concerns over large tree declines in the KNP, mirroring those in eastern Africa over the last 50 years, and local extinctions of marula populations in the north-western KNP, adult trees in the southern KNP were monitored between 2001 and 2010. Annual mortality rates across all adult size classes ranged between 3.2 and 4.6%. Loss of adult marula trees in some areas over the last decade exceeded 25%. Rainfall had a strong influence on mortality rates temporally and spatially, but the distance to the nearest perennial river had little influence. Overall, marula populations continue to decline and further local extinctions are possible. Given the clearly unacceptable trends of decline, the next step is to utilize this information (i) to develop predictive models for the future dynamics of marula populations incorporating all drivers; (ii) to advocate active management of refugia within the park where marula populations are protected from elephant impacts; and in combination with (iii) continued monitoring. Resume Le Sclerocarya birrea subsp. caffra (marula), un grand arbre essentiel en Afrique australe et orientale qui est largement utilise par les hommes et par les herbivores, est en train de decliner a un rythme sans precedent dans le Parc National Kruger (PNK), en Afrique du Sud. Vu l'inquietude croissante au sujet du declin des grands arbres dans le PNK, comparable a celui constate en Afrique de l'Est au cours des 50 dernieres annees, et les extinctions locales des populations de marulas dans le nord-ouest du PNK, les arbres adultes du sud du PNK ont ete suivis entre 2001 et 2010. Le taux de mortalite annuel, dans toutes les classes d'âge adulte, allait de 3,2 a 4,6%. La perte d'arbres marulas adultes a depasse 25% dans certaines regions au cours de la derniere decennie. Les chutes de pluie ont eu une grande influence sur le taux de mortalite, aussi bien dans le temps que dans l'espace, mais la distance par rapport a la plus proche riviere permanente avait peu d'influence. Partout les populations de marulas continuent a decliner, et de nouvelles extinctions locales sont possibles. Etant donne que cette tendance declinante est inacceptable, l'etape suivante consiste a utiliser ces informations pour : 1) developper des modeles predictifs pour la future dynamique des populations de marulas en integrant tous les facteurs impliques ; 2) plaider pour une gestion active de refuges dans le parc ou les populations de marulas seront protegees de l'impact des elephants ; en combinaison avec 3) un suivi continu.

Baobabs (Adansonia digitata) provide products, mainly bark, leaves and fruit, which are used for subsistence purposes and traded to generate cash. Recently, demands for baobab fruit derivatives on the global organic market, namely pulp and seed oil, have increased rapidly, leading to concerns that this may have negative impacts on subsistence users, particularly in areas where there is an existing high dependence on these products, such as West Africa. In contrast, in southern Africa baobab fruit are probably ‘underutilized’ and commercialization would help reduce poverty. This study evaluated the direct-use (subsistence) and income (cash) value of baobab fruit on the livelihoods of baobab fruit harvesters in South Africa. Harvesters were mostly women (98 %), many of whom were unemployed (98 %) and uneducated (70 %). The majority (68 %) received social grants and were involved in informal occupations (55 %), which contributed 35 and 18 % to total annual income respectively. The trade and direct-use value of non-timber forest products contributed 14 and 33 % to annual income, of which, baobab fruit made up 38 and 4 % respectively. Baobab fruit was the only non-timber forest product that had a higher income value (4×) than direct-use value. Cash earned was used to buy food (73 %) and invest in small businesses, suggesting a move from subsistence to cash economy. It is suggested that commercialization of baobab fruit will have far-reaching benefits; and that secured access to trees and investment in local beneficiation will further increase the value of the resource for many marginalized people in southern Africa.

SUMMARYDespite electrification, over 90% of rural households in certain areas of South Africa continue to depend on fuelwood, and this affects woody vegetation structure, with associated cascading effects on biodiversity within adjacent lands. To promote sustainable use, the interactions between anthropogenic and environmental factors affecting vegetation structure in savannahs need to be understood. Airborne light detection and ranging (LiDAR) data collected over 4758 ha were used to examine woody vegetation structure in five communal rangelands around 12 settlements in Bushbuckridge, a municipality in the Kruger to Canyons Biosphere Reserve (South Africa). The importance of underlying abiotic factors was evaluated by measuring size class distributions across catenas and using canonical correspondence analysis. Landscape position was significant in determining structure, indicating the importance of underlying biophysical factors. Differences in structure were settlement-specific, related to mean annual precipitation at one site, and human population density and intensity of use at the other four sites. Size class distributions of woody vegetation revealed human disturbance gradients around settlements. Intensity of use affected the amplitude, not the shape, of the size class distribution, suggesting the same height classes were being harvested across settlements, but amount harvested varied between settlements. Highly used rangelands result in a disappearance of disturbance gradients, leading to homogeneous patches of low woody cover around settlements with limited rehabilitation options. Reductions in disturbance gradients can serve as early warning indicators of woodland degradation, a useful tool in planning for conservation and sustainable development.

Quantifying the Trade in Cycads ( Encephalartos Species) in the Traditional Medicine Markets of Johannesburg and Durban, South Africa. Cycads have been used for traditional purposes for centuries, mainly as a source of starch during droughts and famines. In South Africa, Encephalartos species are traded for traditional medicine (TM) in local TM markets. The 2009 IUCN Red Data assessment for South African flora lists 78% of the 37 indigenous Encephalartos species as “Threatened”, with three species already “Extinct in the Wild” (EW). South African cycads face an extinction crisis, primarily due to collecting for the horticultural trade. The trade in Encephalartos for TM also has a significant impact on several species, and is largely understudied. In this paper, the trade in Encephalartos for TM was quantified in South Africa’s two largest TM markets, Faraday in Johannesburg and Warwick in Durban. Harvesting of South African Encephalartos for TM involves the removal of bark strips and/or whole stem sections. Encephalartos species were sold at 26% and 13% of the stalls at Faraday and Warwick, respectively, with an estimated 9.0 metric tons traded at Warwick in 2009. Stem samples purchased in the markets were assigned to stem diameter size classes using a size class chart, and regression analysis was used to validate the allocations. Most harvesting was from sub-adult and adult cycads, and it appears that bark strips are removed from large arborescent plants, whereas smaller individuals and subterranean-stemmed species are harvested by removing the entire plant. There is generally a positive relationship between stem diameter and leaf base length as well as stem diameter and pith radius. The former can be used as a predictor of stem diameter size class for market samples that prove difficult to assign to diameter classes using the chart. Overall, this is the first study to quantify the trade in Encephalartos for TM in South Africa with reference to the size classes of the plants traded.

Large quantities of plants are traded annually in South Africa's traditional medicine or ‘muthi’ markets. A resource in high demand in the Faraday (Johannesburg) and Warwick (Durban) markets is uMavumbuka, a root holoparasite usually identified as either Hydnora africana Thunb. or Sarcophyte sanguinea Sparrm. subsp. sanguinea. However, rhizomes regularly observed in Faraday between 1994 and 2008 did not resemble either species, thereby suggesting that a third, and undocumented, species was being harvested. This was confirmed when the rhizomes were identified as H. abyssinica A.Br. by an American parasitic plant expert. An ethno-ecological study was initiated to verify its occurrence in selected muthi markets. The study further aimed to investigate the distribution of H. abyssinica through trader interviews, host species localities and some previously misidentified herbarium specimens. The study revealed that H. abyssinica was the only uMavumbuka species present in Faraday and Warwick in 2009. Furthermore, the rhizomes were being harvested in KwaZulu-Natal—an area not previously known to be part of its distribution range. Re-evaluated herbarium vouchers and recent photographs taken in the Kruger National Park have confirmed that H. abyssinica occurs in KwaZulu-Natal, Limpopo, Mpumalanga, Gauteng and Swaziland and hence eastern southern Africa. Fragments of Acacia xanthophloea Benth. roots were identified on 93% of the samples that had host roots attached, and we suspect that H. abyssinica follows the distribution of A. xanthophloea in suitable habitats north from KwaZulu-Natal and adjoining the South African border with Swaziland and Mozambique. Acacia karroo Hayne and A. grandicornuta Gerstner have also been positively identified as host species in South Africa from herbarium records. Plant harvesters in the markets cited the common names of several other species that uMavumbuka “grows under” that may be identified as hosts to H. abyssinica in the future. The collection of specimens in areas identified by the harvesters and in areas of suitable habitat is important to verify the occurrence, distribution and habitat of H. abyssinica in eastern southern Africa.

Campuloclinium macrocephalum is an Asteraceous alien weed that invades roadside vegetation and grassland in South Africa. The role of allelopathy and competition in its invasiveness was investigated using Eragrostis curvula (weeping lovegrass, an indigenous grass), E. tef and Lactuca sativa (lettuce) as test species. Trials were conducted in Petri-dishes, pots and in the field. Root and shoot extracts of adult C. macrocephalum plants did not inhibit seed germination in any test species. The greatest effect was radicle stunting produced by leaf extracts at 10 and 25% w/v. Eragrostis curvula was less tolerant of the extracts than E. tef. Allelopathic effects could however not be confirmed in pot trials evaluating the interference potential of the weed or weed residue effects against E. curvula. E. curvula growth and biomass was not affected by plant densities of one or five C. macrocephalum per pot, whereas C. macrocephalum suffered a 17% mortality and density-dependant trade-offs of size and biomass for survival. Under field conditions C. macrocephalum had a broader ecological niche than E. curvula, invading hygrophilous and undisturbed grasslands not amenable for E. curvula establishment, this included well drained disturbed soils on which the latter proliferated. Evidence of competitive exclusion of E. curvula by C. macrocephalum or vice versa was not detected. The coexistence of both species irrespective of relative density suggested these species have different resource requirements. Allelopathy was not an adequate causal mechanism to explain invasiveness in Campuloclinium macrocephalum. A more traditional hypothesis such as the absence of natural enemies, at this stage, better justifies the weed’s invasion success.

Baobabs are important to people's livelihoods as a source of food, fibre and medicine. Baobab products are increasingly being commercialised and exported around the world, and pressure on the resource is growing ( Sidibe and Williams, 2002 ). This paper examines baobab population structure and trends in northern Venda, South Africa. We compare the density and life stage data of baobabs in four land-use types (plains, rocky outcrops, fields and villages). Villages and fields had higher densities of trees (2.16 ± 0.44 and 1.13 ± 0.52 plants/ha) than plains and rock outcrops (0.96 ± 0.25 and 0.83 ± 0.24 plants/ha). All land-use types had positively skewed size-class distribution (SCD) curves and negative to flat SCD slopes indicating low recruitment relative to adult density. Villages and fields had the highest juvenile densities, but exhibited flat SCD slopes indicating lowest recruitment relative to mature plant densities. High human numbers, minimal use of baobab fruit and no protection afforded to seedlings, explains low recruitment in villages and fields. Recruitment relative to adult density was most successful in the plains, which exhibited the most positively skewed SCD curves, steepest SCD slopes and the highest percentage of juvenile plants. Overall, the population is stable with healthy numbers of mature trees. Mortality is very low, and is attributed to the lack of elephants. Quotients and the permutation index suggest that recruitment and mortality is episodic. It is concluded that current levels of recruitment are enough to maintain this population of long-lived trees. Comparisons are made with communal land elsewhere in Africa and neighbouring conservation areas, which exhibit different demographic patterns. This paper serves as a benchmark in the light of demographic changes that may arise from increased commercial use of fruit and a predicted reduction in rainfall due to climate change.

Forest plant communities were described using two floristic data sets (accompanied by data on soil and former management practices) from the Budongo Forest Reserve (BFR), Uganda – a semi-deciduous tropical rainforest. The first data set featured species basal-area data for woody species, while the other data set featured abundance for woody plants of stem diameter ≥ 2.0 cm. Four forest community types: Pseudospondias microcarpa Swamp Forest, Funtumia elastica–Pouteria altissima Forest, Lasiodiscus mildbraedii–Khaya anthotheca Forest, and Cynometra alexandri–Rinorea ilicifolia Forest were distinguished. Each community is characterised by a group of species, however there are a considerable number of species shared by all four communities. The forest communities show clear separation along gradients of screened soil characteristics (i.e. Organic matter, Na, N, Ca, Mg, and Si), corroborating the results suggested by the canonical correspondence analysis (CCA). For the species basal-area data, Axes 1 and 2 of the CCA explained 18 % in species, and 34 % of the variance in species-environment relations. Whereas, for the abundance data, the amount of information accounted for by the first two axes was 25 % and 44 %, in species variance and species-environment relations, respectively. Axis 1 of CCA was strongly correlated with soil nutrients, while Axis 2 was correlated with logging and arboricide treatment. Accordingly we interpret Axis 1 as an edaphic gradient, while Axis 2 is depicting an anthropogenic disturbance gradient.

Land-use and cover changes around Budongo Forest Reserve (BFR) were analysed from multi-temporal LandSat images (1988 and 2002) and associated field-based studies in 2003–2004. Three major land-use and cover classes: forest/woodland, sugarcane plantations and grassland/shifting-cultivation/settlements were clearly discriminated. The area under sugarcane cultivation increased over 17-fold, from 690 ha in 1988 to 12729 ha in 2002, with a concomitant loss of about 4680 ha (8·2 per cent) of forest/woodland, mainly on the southern boundary of BFR. Land-use and cover changes were a result of (a) agricultural expansion, (b) increasing human population, exacerbated by large influxes of refugees, (c) conflicts of interest and political interference in the management of BFR and (d) unclear land tenure. Agriculture is the main land-use practice and source of income to local people, with commercial sugarcane and tobacco as the primary cash crops. Individual smallholder sugarcane plantations covered distances ranging from 30 to 1440 m along the BFR edge, with no buffer zone, resulting in direct conflicts between farmers and forest wild animals. There is an ever-increasing need for more land for agricultural expansion, resulting in continued loss of forest/woodland on private/communal lands and encroachment into BFR. This unsustainable agricultural expansion and the local people's perception of BFR as an obstacle to agriculture, threatens the conservation of its threatened wild plants (e.g. Raphia farinifera) and the endangered chimpanzees. Therefore, their sustainable management for both development and conservation will require strong and incorruptible institutions that will seek a balance between resource exploitation and conservation. Copyright © 2008 John Wiley & Sons, Ltd.

The differences in knowledge of biological resource use between societal and demographic groups are often poorly understood; yet they are an important element of sustainability. Differences in gender and generational knowledge of locally useful woody plant species in South African savannas are examined. The results showed that young people and middle-aged females were highly knowledgeable. Over half of the total 267 woody plant species in nine use categories (i.e., medicinal, fruits–seeds, fuelwood, beverage, cultural, furniture, craft, fencing and housing poles) had multiple uses. Therefore, differences in knowledge of resource selection and use between social or demographic groups (for example based on gender and age) may appropriately inform conservation prioritisation, planning and monitoring.

CITATION: Esler, K.J. et al. 2008. Riparian vegetation management in landscapes invaded by alien plants: Insights from South Africa. South African Journal of Botany, 74(3):397-400. doi:10.1016/j.sajb.2008.01.168

The impacts of invasive alien plants (IAP) and their subsequent clearing by the Working for Water Programme (WfW) on (a) overstorey (woody plant) vegetation structure, (b) invasion intensity (overstorey aerial cover of woody alien plants) and (c) ground cover, in a temperate to subtropical riparian ecosystem were studied in 1996/7 and again in 2005, in order to provide a longer-term perspective on the effectiveness of WfW clearing. Forty 1000 m2 plots were surveyed and resurveyed, comparing between (a) higher altitude Grassland and lower altitude Savanna, (b) high (>50% invasion intensity) versus low (5 m and to a lesser extent 2–5 m in height, and a large increase in alien plants of

Recovery of indigenous species subsequent to the clearing of invasive alien plants (IAPs) is crucial for ecosystem recovery to occur. However, cleared sites are often just left in the hope that revegetation will occur naturally. In riparian areas of Kruger National Park (KNP), the Working for Water (WfW) Programme has cleared IAPs on a regular basis, but little post-clearance monitoring has taken place. Thus investigating short-term effects of IAPs and IAP clearing on plant community diversity and vegetation recovery provided an ideal opportunity to assess feasible targets of natural ecosystem recovery in similar areas. Vegetation was sampled from twelve transects along the Sabie River in and adjacent to the KNP, before (March/April 2006) and after (March 2007) the annual clearing of IAPs by WfW. Rarefied species richness, alpha diversity and evenness of distribution of species all declined with increasing density of IAPs (Pb 0.05). There was a mean reduction in IAP density of 80% (S.E ± 6%) (P = 0.002) through the clearing by WfW. After clearing of IAPs, indigenous vegetation densities increased, with herbaceous growth forms showing the largest increase in transects that were previously heavily invaded. Thus, in this system, which is relatively undisturbed by human activities, initial recovery of indigenous vegetation can occur without further restorative interventions. This process is more than likely aided by the continuous clearing of IAPs by WfW as this acts to deplete alien seed banks and maintain IAPs at acceptable and manageable levels. © 2008 SAAB. Published by Elsevier B.V. All rights reserved.

This paper compares the occurrence of plant traits in five edaphically matched sites at the Barrens, southwestern Australia and the Agulhas Plain, southwestern South Africa. The two regions are very closely matched in terms of their Mediterranean-type climates, landforms, soil types and disturbance regimes. On both continents, matched sites on all substrata (siliceous sand, quartzite, laterite, limestone and calcareous sand) support sclerophyllous shrublands with a similar mix of growth forms. Soils from all substrata in both Australia and South Africa are extremely nutrient-poor except for the calcareous sands where high levels of phosphorus were recorded. Contrary to expectations, Australian soils are not generally less fertile than their South African counterparts. The frequency of species in different leaf consistence categories was similar on the two continents, as was the leaf specific mass of overstorey shrubs from all substrata. Woody plants with leaf spines are significantly more frequent on Australian nutrient-poor substrata. Among woody plants, species with canopy-stored seed are significantly more frequent on Australian nutrient-poor sites, whereas species with bird-dispersed fruits and inter-fire germination are significantly more frequent on South African limestone and calcareous sand. There was good evidence for convergence between the two continents in the frequency of other seed biological traits. The study indicates strong convergence between Australian and South African shrublands in the frequency of a wide range of traits relating to plant form and function. Examples of non-convergence are probably due to regional and historical processes rather than differences in the contemporary physical environments of the two study areas.

Banksia menziesii is a tree at the mesic end (Swan Coastal Plain) of its range and a shrub at the xeric end (Eneabba Plain). Plants at the xeric end produced, on average, as many cones, set 2.3 times as many seeds and stored 8.8 times as many viable seeds in the crown, as those at the mesic end. Plants on road verges had, on average, 2.5 times larger crowns than those at least 50 m further from the road. Road edge plants produced, on average, 2.5 times as many cones, set 3.1 times as many seeds and stored 3.7 times as many viable seeds as non-edge plants. Greater fecundity at the xeric end, including the road verges, could help offset the greater incidence of adult deaths and the reduced likelihood of seedling recruitment after fire at Eneabba.

The lack of scientific rigour in analysing ethnobotanical surveys has prompted researchers to investigate ways of quantitatively describing their data, including the use of ecological diversity indices. There are numerous indices and measures available to describe sample diversity. Twenty-two measures of species richness, diversity and evenness were reviewed using six sets of ethnomedicinal data derived from 50 formal muti shop traders (of different ethnicities) and 100 informal street traders of traditional medicine in Johannesburg, South Africa, and a seventh data set from traders on the western boundary of the Kruger National Park, South Africa. The diversity measures were coupled with species accumulation curves to construct cumulative diversity curves used to determine the minimum viable sample size on which a diversity index should be based, and to better understand the differences in the relative diversities of the samples. Distinct differences in the relative abundance and diversity of plants sold by street traders and shop traders were evident. Species diversity and evenness was found to be higher in shops, thus resulting in a lower dominance in the sale of certain plant species compared to the street traders. A survey of an informal market should include no less than 35 research participants compared to no less than 20 for the muti shops. The use of selected indices of species richness (Margalef's), diversity (Shannon, Simpson's, Fisher's alpha, Hill's numbers) and evenness are recommended as a means of describing patterns exhibited within ethnobotanical data.

In Tanzania, well-defined land tenure and resource protection apply in forest reserves which account for 30% of forested land, while the remaining 70% (mostly miombo woodlands) are village and general lands with very limited protection. The aim of this study was to determine local people’s ownership rights, knowledge and institutional capacity for sustainable management of resources in forest reserves and general lands. Data were collected using participatory rural appraisal, structured and semi-structured interviews, as well as aerial photographs and landsat images. In general lands, woodlands declined by 50% between 1964 and 1996, bushlands and croplands increased by 599%, and settlements and homegardens increased by 277%. These land use and vegetation structure changes are attributed to harvesting for charcoal production and shifting cultivation. The continued decline in aerial woodland cover in the general lands suggests that common property regimes do not function in the area. Local institutional capacities are weak in enforcing control mechanisms to check the overuse of resources, which tends to approximate open access conditions. The issues of land tenure and village empowerment are not only institutional, but also political in nature. Government institutions should provide and motivate for an enabling environment, including acknowledgement of traditional knowledge, well-defined property rights and operational village by-laws. In order to ensure equity and sustainable development of natural resources, the paradigm shift in management is important whereby communal goods are to be managed for the benefit of the local society.

Rising demand for medicinal plants has led to increased pressure on wild plant populations. This, combined with shrinking habitats, means that many species in South Africa are now facing local extinction. In 1997, a study was initiated to determine the extent of trade in medicinal plants in the South African Lowveld (the low lying plains to the east of the Drakensberg escarpment), and to investigate socio-economic factors influencing trade and resource management. Trade was not as extensive in the Lowveld as in major urban markets such as Durban or the Witwatersrand (Johannesburg and surrounding towns), either in terms of the quantity, number or range of species sold, or the numbers of people relying on the trade for an income. In markets assessed in Mpumalanga Province, 176 species were identified (71% of the vernacular names encountered in the market place), representing 69 plant families. In Limpopo, 70 different species were identified (84% of the vernacular names encountered in the market place), representing 40 families. Imports were significant in Mpumalanga (33% of the plants on offer), mainly from Mozambique. A detrended correspondence analysis showed substantial differences between species traded in Mpumalanga and those sold in Limpopo. There was little variation in the species stocked by vendors in Mpumalanga, regardless of the season, the attributes of the seller, or whether business was carried out in urban or rural areas. In contrast, there was considerable variation in the stock inventories of the Limpopo traders. Despite the lower levels of local trade, increased harvesting pressure is being experienced regionally, to meet demand in metropolitan centres such as the Witwatersrand. This study showed considerable local variation and complexities in the harvesting and marketing of medicinal plants, with both a national and an international dimension. This dual spatial scale presents both opportunities and challenges in the management of these plants, which need to be addressed simultaneously, particularly with respect to research requirements and development of predictive models and capacity. Cooperation in conservation strategies and policies is required at regional, national and international levels, while ensuring that management initiatives take into account local market conditions and the socio-economic realities facing both consumers and those who depend on the trade for their livelihoods.

SUMMARY This paper presents a comprehensive assessment of the contribution of communal resources to households in Bokong and Tsehlanyane in Lesotho. It argues that communal resources are an extremely important element in the livelihoods of people in the study area. It uses households as units of analysis in order to gain an understanding of the role that communal resources play at the micro level before any extrapolations are made to the regional and national levels. A household survey, guided by a detailed semistructured questionnaire, was used. Ten newly constructed houses and vegetable garden enclosures were sampled to categorize and count all poles used to build them. The amount of thatch grass used in building those houses was also estimated. The results indicated that communal resources play a central role in the livelihoods of people in the area with firewood ($1492), crops ($1363) and wild vegetables ($774) recording the highest annual use values per household−1 yr−1. The total present value was e...

Miombo (Zambezian savanna) woodlands in protected and public (communal) lands of eastern Tanzania were examined to compare standing and harvested wood stocks and investigate different human disturbance gradients between the two utilization/management regimes. The standing volume in the forest reserve was 47±3.38 ( S.E. ) m 3 ha −1 and the total removal volume (calculated from stumps) was 7.1±1.18 m 3 ha −1 . In the public lands, the standing volume was only 16.7±2.26 m 3 ha −1 and the total removal volume was 19.62±2.58 m 3 ha −1 . Harvesting intensity decreased with increasing distance from village settlements and reserve boundaries but the pattern had no significant overall impact on standing stocks of wood. The Dar-es-Salaam–Morogoro highway, which bisects the study area is the major axis of disturbance. Multivariate analysis indicated that the linear combinations of physiographic variables significantly influence the pattern of tree harvesting. Commercial harvesting for charcoal overrides patterns from other harvesting purposes because of economic incentive and the wide range of species and size classes harvested. The estimated annual wood removal for all uses of 6.38±2.39 m 3 ha −1 in public lands exceeds the reported mean annual increment (MAI) in the study area of 4.35 m3 ha−1 yr−1. Thus present patterns of harvesting are changing the structure and composition of the vegetation, especially in the communal areas and are not sustainable. This will increase pressure for harvesting in reserves.