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The late dry season is a period when forage resources become limited in some African savannas that can induce a strong demographic bottleneck in herbivore populations with limited access to resource heterogeneity. This study determined forage quality and quantity between wetlands and drylands habitats during the late dry season. We subjectively sampled forage characteristics in four habitat types around the distal reaches of the Tsum Tsum floodplains of the Okavango Delta during the late dry season of 2015. The habitat types were mopane and sandveld woodland far from floodplains (two major dryland habitat types), sandveld habitats that receive soil moisture inputs from adjacent floodplains (wet sandveld) and sedgeland habitat within the floodplain. Leaves collected from forage in each habitat type were oven dried, milled and analysed for total nitrogen. Data of greenness, height, biomass and protein were analysed using Kruskal-Wallis test. Forage in wet sandveld had by far the highest protein content (~16%) of all habitat types but forage height and biomass were very low, whereas sedgelands had the highest biomass of adequate-quality forage, while dryland communities had the lowest quantity and quality of forage. Thus, foraging between a higher-biomass, adequate-quality reserve resource (sedgeland) and a high-quality but low-quantity bridging resource (wet sandveld) can help to ensure a balanced protein and fibre intake during the late dry season. Our study demonstrated the importance of wetland habitats for providing green forage with sufficient biomass and protein to sustain herbivores over the late dry season.

Malnutrition is a major health problem especially in many developing nations. Ironically, communities that suffer from undernourishment especially in rural areas often have plenty of nutritious wild foods. However, stigma against such foods, limited seasonal availability, limited or no diversification of such foods can be hindrance to the consumption and all-year accessibility of these foods. This project has developed and demonstrated simple, affordable processes to potentially produce dried soups containing mopane worms, an edible insect common in arid and semi-arid southern African countries. The manufacturing of these pre-mixes requires relatively simple, easy to use equipment to process the raw materials. The enhanced protein content and possibly quality of the developed products can be beneficial especially to people who have less access to meat products. This piece has demonstrated the enhancement of nutrition by making “scary-looking” worms become part of our meals without seeing its presence. The potential use of the developed products depends on pending consumer sensory tests, nutrient bioavailability and technology transfer uptake and ultimately its commercialisation by Small and Medium Enterprises.

The southern African Mopane savanna is a water-limited ecosystem and an increase in woody plant abundance often results in the suppression of herbaceous plants. In an attempt to counter this effect, the thinning or even total clearing of all woody plants is a common practise in South Africa. Since the outcome of woody plant removal is determined by both negative and positive responses to tree removal, a study was conducted to establish if all tree woody species have the same impact on the herbaceous layer. The study area featured a dense stand of Colophospermum mopane, interposed with isolated colonies of Salvadora australis, each forming its own characteristic habitat. Seven plots (65 m×180 m) were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0%) to plots thinned to the equivalent of 10%, 20%, 35%, 50% and 75% of the leaf biomass of a control plot (100%) with a tree density of 2711 plants ha −1 . The S. australis -habitat, in comparison to the larger C. mopane- habitat, supported a superior cover of herbaceous plants. The S. australis -habitat supported a larger proportion of perennial grasses, acting as valuable seed resources of these and other herbaceous plants. Differences in the soil nutrient status and soil water between the C. mopane - and S. australis -habitats are likely determinants of these differences. A poor ground cover existed at high tree densities of the larger C. mopane -habitat. A rapid colonization of bare ground by herbaceous plants resulted with increasing intensity of tree thinning of the major C. mopane -habitat, but the opposite appeared to happen on the S. australis -habitat. The S. australis trees are considered critical in maintaining conditions favourable for the persistence of the associated herbaceous component. Thinning or removal of S. australis is therefore considered undesirable.

Vegetative response aspects of climate change studies include the determination of vegetation cover changes across climatic gradients. Vegetation characteristics and soil moisture measurements were obtained from four locations with decreasing rainfall along the Botswana Kalahari transect. These are referred to as Pandamatenga, (698 mm year−1), Maun (460 mm year−1), Okwa (407 mm year−1) and Tshane (365 mm year−1). Trends in major vegetative cover and soil components included species types and richness assessments which reflected certain changes southward but also showed interesting degrees of variability. This occurred despite the apparent homogeneity of the Kalahari sands and predominantly semi-arid savanna shrub–woodland vegetation cover. Despite linear decreases, both in rainfall and soil moisture content, results indicated high soil moisture variability at the Okwa location which relates to unique climatic and geological factors. Also many species are unique to specific locations for instance Pandametanga is characterized by Zambesian species while the Maun location is characterized by Colophosphermum mopane. This changes southwards as Acacias become more dominant and significantly co-occur with Grewia flava. While the average total numbers of plants decreased, total numbers of different species varied little from the wetter to the drier end of the moisture gradient. The association between rainfall and woody cover is negative implying that canopy cover extents (in terms of vegetation density) increase along the gradient due to increases in bush encroachment in drier areas. Therefore, while representing a continuum in terms of species numbers, in other respects (e.g. species types and ground cover components) vegetation zones in the Kalahari may be regarded as discontinuous units. Differences between mapped vegetation zones may be accounted for in terms of relatively unique ecosystem factors which function partly in response to geological conditions and partly in response to local (as opposed to regional) climatic factors. This appears to have led to ecosystem adaptive measures (in terms of species responses) rarely mirrored elsewhere along the gradient. Hence adaptability in terms of species migrations in response to relatively rapid climate changes may not readily take place over the Kalahari in Botswana.

The numbers of livestock and wildlife that can be supported in an arid environment such as the Hoanib River catchment, north-western Namibia, are determined by annual and seasonal availability of grazing and browsing. The availability and abundance of vegetation was investigated in eight focus-study areas across the catchment. The vegetation of the focus area was observed to behave in a non-equilibrial manner in that it was dependent on annual rainfall rather than intensity of landuse. The Zurich–Montpellier method of vegetation assessment was used for the evaluation of vegetation plots. The amount of dry season grazing was also dependent on the previous season's rainfall, with ‘dead grass’ and perennial grass only available after an ‘above average’ rainfall season. Vegetation communities were dominated by mixed Colosphosermum mopane woodlands in the 100–350 mm rainfall zone, while perennial grasses dominated the 50–100 mm rainfall zone. While the bulk rangeland appeared not to be disturbed by landuse, a 2 km ‘sacrifice zone’ around water sources was found to have changes in vegetation species and abundance. During below-average rainfall seasons and drought, when there is limited or no grazing, browse becomes the most important source of nutrition for domestic stock and wildlife.

The investigation was conducted on an area covered by a dense stand of Hardwickia mopane (Leguminosae: Caesalpinioideae). Seven plots (65×180 m) were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0%) to plots thinned to the equivalent of 10, 20, 35, 50, and 75% of the leaf biomass of a control plot (100%) with a tree density of 2711 plants ha−1. Thinning was completed during 1989 and the soil water study was conducted during the 1990/91 and 1991/92 seasons with the aid of a neutron water meter. The study area, before thinning, was characterized by the virtual absence of herbaceous plants with severe soil degradation in the form of surface erosion and crust formations. Increased infiltration of rainwater was measured in the thinned plots and this was associated with the establishment of herbaceous plants, mainly grasses. The soil water was predominantly held at a very shallow depth ( 450–900 mm soil zone show marked increases associated with specific rainfall events. Mean evapotranspiration water losses varied seasonally, but were generally much higher in the 0% plot (grass only plot), which confirmed that grasses use soil water more rapidly than the H. mopane trees. Evidence is presented that the roots of the H. mopane trees are able to utilize soil water at a matric potential lower than that of grasses (ψ

Ten species were selected based on their economic value in order to study and compare their growth, nutrient uptake pattern, AM-fungal infection etc. in both mine spoil and normal cultivated soil in pot culture. In general, per cent root infection and number of viable AM fungal spores in the rhizosphere of the plant species grown in mine spoil were higher compared to those in normal cultivated soil. Mine spoil had supported significantly higher growth of Prosopis juliflora , Salvadora oleoides and Cenchrus ciliaris compared to normal soil. Concentrations of phosphorus, potassium and calcium in plants growing on gypsum mine spoil were higher than observed in normal soil. In general, micronutrient concentrations (namely Cu, Zn and Fe) were lower in all the plant species growing in normal soil. Salvadora oleoides , Colophospermum mopane and Pithecellobium dulce were identified as calcium-loving plants. All the species tested can be employed for rehabilitation of gypsum mine spoil.

Data are presented on surface-active invertebrate faunal composition in mopane woodland in northwestern Zimbabwe during the dry season, as assessed by pitfall trapping. Collembola were numerically dominant comprising about 60% of fauna trapped. Insects comprise just under 30% of the catch and arachnids approximately 10%. Amongst the insects, ants were most numerous and are evidently dominant members of the invertebrate fauna. Termites (also extremely important members of the invertebrate community of the area) were only caught in small numbers, demonstrating one limitation of the pitfall trap as a tool for surveying faunal assemblages. In terms of biomass, insects dominated, comprising almost 81% of the total, followed by Collembola (6·3%) and Arachnida (5·5%). The spiders show high diversity and species richness (H’ = 3·725; J’ = 0·81; S = 100), whilst the beetles and ants are less species rich and showed lower diversity. A large number of undescribed species are represented in the collections. Faunal composition shows characteristics typical of arid environments.