Increasing representation of localized dung beetles across a chronosequence of regenerating vegetation and natural dune forest in South Africa

Aim Species assemblages with high proportions of localized taxa occur in regional islands with a history of strong eco‐climatic separation from adjacent systems. Current disturbance in such islands of relictualism or endemism disrupts the distinctive local character in favour of regionally distributed taxa with a wider range of tolerances. However, rehabilitation of the system should restore the localized biota. Thus, we used biogeographical composition to assess progress towards restoration of the dung beetle fauna associated with such an island of endemism following dredge‐mining. Location The study was conducted in natural coastal dune forest and a 23‐year chronosequence of regenerating dune vegetation in the Maputaland centre of endemism, KwaZulu‐Natal, South Africa. Methods Dung beetles were trapped in eight stands of regenerating vegetation of different ages (< 1 year to ~21 years) and in four stands of natural dune forest with differing ecological characteristics defined by measurements of vegetative physiognomy and microclimate. Species groups defined from multivariate analysis of biogeographical distribution patterns and vegetation associations were used to demonstrate quantitative compositional changes in the dung beetle assemblages across the chronosequence to natural forest. Results Three biogeographical groups were defined. One group comprised species widespread in southern Africa or both southern and east Africa. The other two groups were endemic, one to the east coast and the other to Maputaland. There was a general trend from dominance by regionally distributed dung beetle taxa to dominance by locally distributed taxa across the chronosequence of regenerating vegetation from grassland, to open Acacia karroo thicket, to dense A. karroo‐dominated woodland. However, this trend was linked closely to the relative physiognomic and microclimatic similarity between the regenerating vegetation and natural forest. Thus, proportions of locally distributed taxa were lower in older chronosequence woodland (~18–~21 years) with its low canopy cover and open understorey than in dense early chronosequence woodland (~9–~12 years), which is physiognomically and microclimatically closer to species‐diverse natural forest with its dense canopy and understorey. Overall, the present dung beetle community comprises five species groups. Single widespread (21 spp.) and endemic groups (14 spp.) showed similar patterns of association with early chronosequence grassland and open thicket stands. A single widespread (3 spp.) and two endemic shade‐associated groups (3 and 11 spp.) showed differing patterns of association centred, respectively, in late chronosequence woodland, natural forest, or all shaded stands. Main conclusions At 23 years, vegetative regeneration is still at an early stage, but abundant activity of most, although not all species recorded in natural forest, is recovered with the closure of the woodland canopy at ~9 years. Compositional differences with respect to natural forest vary closely with vegetative physiognomy and its effect on the microclimate. Therefore, full compositional recovery is dependent on the re‐establishment of natural forest physiognomy and microclimate.     

Patterns in the diversity and endemism of extant Eocene age lineages across southern Africa

Southern Africa boasts a wealth of endemic fauna and flora, comprising both massive recent radiations such as those characteristic of the Cape flora, and solitary ancient species such as the peculiar desert gymnosperm Welwitschia. This study was undertaken to identify ancient biological lineages (tetrapod and vascular plant lineages of Eocene age or older) endemic to southern Africa, and to map their distribution across the region. Twenty‐seven (17 plant and ten animal) lineages were identified, and distribution maps were generated for each of them across 74 operational geographic units, which were then combined into total endemism and corrected weighted endemism per unit area. Total endemism peaked along South Africa's coast and Great Escarpment, but in the case of weighted endemism high values were also recorded along other portions of the Great Escarpment further north. A review of the lineages sister to southern African ancient endemic lineages showed that these are often globally widespread, and many of them differ substantially from the southern African ancient lineages in terms of morphology and ecology. The mechanisms of ancient lineage survival in the region are discussed, and their importance for conservation in southern Africa is emphasised.     

Ethnobotanical plant uses in the KwaNibela Peninsula, St Lucia, South Africa

Ethnobotanical field studies were conducted for the first time in the KwaNibela Peninsula of southern Maputaland, KwaZulu-Natal, to document indigenous knowledge about useful plants. The vernacular names and uses of 82 plant species were recorded and compared to published Zulu and Swazi knowledge. Medicines for skin disorders, toothache, wounds, worms, chest and throat ailments, infertility and purgatives are still commonly used. Superstition and divination play a major role in the traditional knowledge system of the people of KwaNibela with 24 plants used for this purpose. Three KwaNibela medicinal plants (Erythroxylum delagoense, Putterlickia verrucosa, and Teclea natalensis) appear to be new records, not previously reported in the general scientific literature. The list also includes 61 novel uses of plants and another 15 new variations on known (published) uses. Ten previously unpublished vernacular names are presented, together with an additional 19 new variants of known names. These new additions to the scientific literature confirm that indigenous knowledge in KwaZulu-Natal is not yet completely recorded.     

Coral community structure and risk assessment of high-latitude reefs at Sodwana Bay,South Africa

The importance of studying coral communities at different spatial scales is acknowledged in a growing volume of scientific literature, and principles of landscape ecology were thus used to elucidate the patterns in coral community structure on the high-latitude reefs in South Africa. These reefs are at the southernmost distribution of this fauna in Africa, are surprisingly species rich, and represent a biodiversity peak in this fauna south of the equator, regardless of the marginal nature of the environment. Coral community patterns were identified on and between the reefs at Sodwana Bay, justifying the grouping of reef areas in distinct zones. A number of landscape components were identified, ranging from the entire reef complex (10 km scale), individual reefs (1 km scales) and reef zones, to components that were separated using multivariate statistical analysis of transect data. These components transcended spatial similarities, e.g. the fore-reef on Five-mile Reef was not similar to the fore-reef on Seven-mile Reef, but was rather grouped with the reef flat on Two-mile Reef. This information was “translated” into an index of management intervention, based on risk assessment, and was generated using parameters that measure susceptibility to crown-of-thorns feeding, bleaching, diver-related damage and swell-induced breakage. We also assessed was the time elapsed since the last major disturbance and the proximity to the only boat launch site, a proxy measure of continuous disturbance. The risk assessment suggested that conservation management is most needed in the stable and “climax” coral communities that are usually characterised by a near-equal mix of hard and soft corals at maximal coral species diversity.     

DISTRIBUTION AND DIVERSITY OF MKUZE SWAMP FISHES DURING A SUMMER FLOOD

SUMMARY

Very little information is available on the fishes of the Mkuze swamps and this paper presents the results of an ichthyofaunal survey conducted in March 1988. The study, which coincided with a major river flood, determined that the fish fauna was considerably more diverse than expected and 25 species were collected from 31 localities. Several distinct communities are recognized including a river channel/floodplain community, lagoonal community, feeder stream community and lower swamp community. The subtraction of tropical freshwater fish species in the region is documented and a complete checklist for the Mkuze River system, including several new records from this survey, is presented.