Plant community and landscape patterns of a floodplain wetland in Maputaland, Northern KwaZulu-Natal, South Africa

The lower Mkuze River floodplain is located east of the Lebombo Mountains on the Maputaland Coastal Plain in northern KwaZulu‐Natal, South Africa. The vegetation ecology of the floodplain was examined using the hierarchical framework described by landscape ecology theory. The smallest spatial scale to which the vegetation of the floodplain was described was the relatively homogeneous units of plant communities. From a landscape ecology perspective this level of analysis is referred to as the grain. Six plant communities were identified using two‐way indicator species analysis (TWINSPAN) classification. The distribution of these plant communities were correlated to an underlying inundation‐sedimentation gradient using the ordination technique, detrended correspondence analysis (DCA). This correlation provided a useful foundation for the examination of ecological processes and phenomena at the next higher, spatially coarser level within the landscape hierarchy, namely the reference level. This reference level was described by three functional types delimited by differing flooding and sedimentation regimes. The use of landscape ecology theory guided the interpretation of results by explicitly recognizing the importance of spatial heterogeneity, hierarchical organization and dynamics, and proved invaluable in developing process‐based understanding of the vegetation ecology of the lower Mkuze River floodplain.     

Area utilization patterns of humpback dolphins (Sousa plumbea) in Richards Bay, KwaZulu-Natal, South Africa

Geographically referenced data on humpback dolphin (Sousa plumbea) distribution and behaviour were collected in Richards Bay, South Africa, between 1998 and 2006. Utilization distributions presented a clear pattern in the distribution of dolphin activities and use of various locations within the study area. The 50 % kernel density estimate (core area) for foraging/feeding (2.1 km²) was clustered around the harbour mouth (including the shark net installation). The core areas for resting, socialising and travelling were more widespread (>2.95 km²). A mixed effects model indicated that location (longitude and latitude), distance from shore, year and group size are important variables in predicting foraging/feeding behaviour as opposed to other behaviours. The resting core was found in the southern part of study area and socialising was less clustered. This indicates preferential use of certain areas for specific behaviours. The overlap of foraging/feeding areas with stationary fishing gear (shark nets) and boat traffic are a major concern due to the risk of human-induced incidental mortalities. Any future alteration of the coastal area of Richards Bay, particularly development in the harbour, should be considered carefully, as further intrusion into areas critical to humpback dolphins, such as their foraging grounds, will inevitably carry negative implications for this already severely impacted population.     

Vegetation variation within and among palustrine wetlands along an altitudinal gradient in KwaZulu-Natal,South Africa

The variation in graminoid species composition and diversity and the distribution of photosynthetic pathways among 66 wetlands in KwaZulu-Natal, South Africa, and within six of these wetlands was described and related to measured physical parameters, using multivariate and univariate techniques. Altitude, which ranged from 550 m to 2120 m, accounted for most variation among wetlands, with an almost complete turnover of species along this gradient. Landform setting was less important in explaining overall species composition, but relationships of individual species were revealed (e.g. Eleocharis dregeana showed an affinity for depressions). Within a wetland there was an almost complete turnover of species along a gradient of wetness, as described using soil morphological criteria. Most species were consistently associated with the same wetness zones across different wetland sites, e.g., Phragmites australis with the wettest zone, Pycreus macranthus with the intermediate zone, and Eragrostis plana with the least wet zone. The occurrence and abundance of different photosynthetic pathway types depended on altitude and degree of wetness. At high altitudes, C₃ sedges, notably Carex acutiformis, dominated the wettest zone and C₃ and C₄ grasses and sedges dominated the intermediate and least wet zones. At mid altitudes, C₃ and C₄ sedges and C₃ grasses dominated the wettest zone, C₃ and C₄ grasses and sedges dominated the intermediate zone and C₄ grasses dominated the least wet zone. Low altitude sites showed a similar distribution of photosynthetic pathways as mid-altitude sites, but C₃ species were less abundant. Species richness was positively associated with the log of wetland size and, at the level of an individual wetland, species richness and evenness were found to be consistently greater in the intermediate and least wet zone compared with the wettest zone. The management implications of the results are discussed in the light of continuing anthropogenic loss of wetlands in the study area and global climate change.     

Killickia (Lamiaceae): a new genus from KwaZulu-Natal, South Africa

The genus Killickia is described to accommodate the South African endemic species formerly placed in Micromeria sect. Hesperothymus . Morphological data, as well as results from unpublished phylogenetic studies support its separation from the genera Micromeria and Clinopodium . A new species Killickia lutea Bräuchler is described and three new combinations are made. Killickia is characterised as comprising solitary- or few-flowered cymes, a campanulate to subcampanulate (obconical) calyx with similar teeth, a corolla tube with two pubescent ridges and nutlets with scattered minute hairs. A thickened marginal vein in the leaves as typical for Micromeria is absent. As currently understood all species are restricted to the Drakensberg mountains and KwaZulu-Natal Midlands in eastern South Africa. A key to the species, brief notes on anatomy and ecology are provided.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 575–586.     

Treatment of Cryptococcal Meningitis in KwaZulu-Natal,South Africa

Background

Cryptococcal meningitis (CM) remains a leading cause of death for HIV-infected individuals in sub-Saharan Africa. Improved treatment strategies are needed if individuals are to benefit from the increasing availability of antiretroviral therapy. We investigated the factors associated with mortality in routine care in KwaZulu-Natal, South Africa.

Methodology/Principal Findings

A prospective year long, single-center, consecutive case series of individuals diagnosed with cryptococcal meningitis 190 patients were diagnosed with culture positive cryptococcal meningitis, of whom 186 were included in the study. 52/186 (28.0%) patients died within 14 days of diagnosis and 60/186 (32.3%) had died by day 28. In multivariable cox regression analysis, focal neurology (aHR 11 95%C.I. 3.08–39.3, P<0.001), diastolic blood pressure <60 mmHg (aHR 2.37 95%C.I. 1.11–5.04, P = 0.025), concurrent treatment for tuberculosis (aHR 2.11 95%C.I. 1.02–4.35, P = 0.044) and use of fluconazole monotherapy (aHR 3.69 95% C.I. 1.74–7.85, P<0.001) were associated with increased mortality at 14 and 28 days.

Conclusions

Even in a setting where amphotericin B is available, mortality from cryptococcal meningitis in this setting is high, particularly in the immediate period after diagnosis. This highlights the still unmet need not only for earlier diagnosis of HIV and timely access to treatment of opportunistic infections, but for better treatment strategies of cryptococcal meningitis.     

Quartz Knapping Strategies in the Howiesons Poort at Sibudu (KwaZulu-Natal,South Africa)

The variability associated with Sibudu''s Howiesons Poort Industry highlights the unpredictable trajectory of technology in the Middle Stone Age. We reach this conclusion through a study of the technology on quartz from one of the Howiesons Poort layers (Grey Sand) from Sibudu rock shelter. Quartz bifacial technology has previously been described at the site, but this new in-depth study of the quartz technology reveals other strategies. First is the recurring employment of bipolar knapping, formerly considered as a defining feature of the Later Stone Age. Secondly, we highlight a laminar technology with emphasis on small quartz bladelets. Bipolar cores are most common, followed by prismatic cores. The knapping strategies in Grey Sand seem to involve systematic recycling and the deliberate production of microliths.     

Neogosseidae (Gastrotricha,Chaetonotida) from the iSimangaliso Wetland Park,KwaZulu-Natal,South Africa

Among the mostly benthic gastrotrichs, the Neogosseidae (Gastrotricha, Chaetonotida) are particularly interesting from an evolutionary point of view in virtue of their planktonic lifestyle; yet, they are poorly known and uncertainties concerning morphological traits hamper accurate in-group systematics. During a recent survey of meiofauna in the iSimangaliso Wetland Park, South Africa, two species of Neogosseidae were found in a freshwater pond near Charter’s Creek on the Western Shores of Lake St Lucia. Based on morphological traits, one species has been identified as Neogossea acanthocolla, originally described from Brazil, while the other, affiliated to the genus Kijanebalola, is proposed as new to science. Using a combination of differential interference contrast and scanning electron microscopy, fine anatomical details were observed and are here discussed in a larger taxonomic framework, especially regarding Kijanebalola devestiva sp. n. Results have also provided reasons for a revision of the diagnostic traits of Kijanebalola, Neogossea and the whole Family Neogosseidae. Besides expanding awareness about the biodiversity hosted by South Africa’s first UNESCO World Heritage Site, our study will be beneficial to future phylogenetic studies of the Gastrotricha based on morphology, by allowing the selection and/or a more precise character coding of traits of phylogenetic relevance.     

Distribution and population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal, South Africa

We report the current species distribution and population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal Province (KZN), South Africa, based on an analysis of estimated area of occupancy and estimated home range size. This estimate suggests a total population size of approximately 11,000 individuals for KZN. Much of the province is uninhabited, with a density in occupied areas of approximately 1.8 animals per km(2). The current population size may be more than an order of magnitude smaller than historical population size. Chacma baboons now exhibit a highly fragmented and discontinuous distribution in KZN, with 58% of the population residing within protected areas, and more than half of these troops reside in areas >1,500?m above average sea level. The small population and highly fragmented distribution of chacma baboons in KZN, combined with rapidly increasing human population size and transformation of natural habitat, suggest this species requires greater conservation attention.     

Koalas use young Eucalyptus plantations in an agricultural landscape on the Liverpool Plains,New South Wales

Summary Revegetation within cleared farming landscapes offers the potential to restore habitat for many woodland‐dependent species that have declined since European settlement. Most species of arboreal marsupials require hollows for breeding and diurnal shelter, a resource that is usually available only in old trees; however, this constraint does not apply to the Koala. In this study, we describe the occupancy and use of young (4‐ to 7‐year old) eucalypt plantations by Koalas in a predominantly cleared landscape used for intensive cropping and grazing. We compare Koala occupancy in 27 eucalypt plantations, 5 paddocks and 11 remnant forest and woodland sites, and we report the relative usage of these three land cover types by two adult male Koalas that were radio‐tracked for 5 and 7 months using GPS transmitters. Koalas were recorded using young eucalypt plantations at 7 sites and remnant forest and woodland at 7 sites. Both radio‐collared Koalas used eucalypt plantations more than expected based on the availability of this land cover type in their home‐ranges. Occupancy of young eucalypt plantations and remnant patches by Koalas was strongly influenced by the proximity of these sites to remnant vegetation.     

High Burden of Human Papillomavirus (HPV) Infection among Young Women in KwaZulu-Natal,South Africa

Objectives

HPV infection causes cervical cancer, yet information on prevalence and risk factors for HPV in Africa remain sparse. This study describes the prevalence of HPV genotypes and risk factors associated with HPV among young women ≤ 30 years of age in KwaZulu-Natal (KZN), South Africa.

Methods

Cervicovaginal lavage samples were tested for HPV genotypes in 224 women enrolled in a prospective cohort study. Clinical, behavioural and demographic data were collected. We measured prevalence of HPV genotypes and using logistic regression, examined for factors associated with HPV.

Results

Median age of participants was 21 years [interquartile range (IQR):18–23]. The overall prevalence of HPV was 76.3% (171/224) with multiple and single genotypes prevalent in 56.3% and 20.1% of women respectively. Proportion of women with high-risk genotypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56 and 58) was 54.5%. Women not living with their partner [adjusted odds ratio (aOR)] = 3.42 95% CI1.22–9.60; p = 0.019), was significantly associated with HPV infection and high-risk HPV genotype infection.

Conclusion

The high burden of HPV and associated risk behaviours highlight the need to intensify behavioural interventions to prevent HPV acquisition in young women. The large scale delivery of HPV vaccine should be prioritised to prevent HPV acquisition and reduce HPV-related morbidity.     

Reproduction and the unusual condition of hermaphroditism in Sarcophyton glaucum (Octocorallia,Alcyoniidae) in KwaZulu-Natal,South Africa

The genus Sarcophyton is an abundant soft coral on the marginal, high-latitude reefs in KwaZulu-Natal. A 2-year study on reproduction in the most common species,S. glaucum, revealed that gametogenesis in male and female colonies takes 9–10 and 16–18 mo, respectively, in this gonochoric, seasonal, broadcast spawner. Gametogenesis and spawning are synchronised in and between colonies, and with other common soft corals on the reefs. Spawning occurs annually in March between full and new moon with the release of spermsacs and the mature oocytes, the smaller oocytes being retained for further development. Thus far, the reproductive attributes of S. glaucum are comparable with other studies on the genus. However, the KwaZulu-Natal population of S. glaucum manifested the unusual attribute of hermaphroditism in 9% of the colonies, these having Stage I and II spermaries and predominantly Stage III and IV oocytes in their polyps. Small numbers of Stage I and II oocytes indicated that such colonies may be simultaneous hermaphrodites but this could not be confirmed. The complex reproductive strategy and associated measure of hermaphroditism in S. glaucum on KwaZulu-Natal reefs are discussed in terms of the species’ recruitment success in this marginal, high-latitude environment.     

Seed removal patterns of pioneer trees in an agricultural landscape

The seeds of most tropical plants are dispersed by animals, many of which also act as seed predators. Shifts in animal community composition, such as those driven by the clearing of native vegetation, are therefore likely to drive changes in plant recruitment. We used manipulative experiments excluding ants, small rodents, and birds to quantify the relative impacts of these granivores on animal-dispersed pioneer trees (ADPT) in fragments of savanna vegetation and adjacent soy plantations in Brazil’s Cerrado. We found that ants were the main consumers of ADPT seeds, that the rates of seed removal varied with seed size, and that removal rates were higher in savanna fragments than in soy plantations. However, we also found significant interactions between habitat type, seed species, and the type of seed predator being excluded. Our results underscore how challenging it can be to predict the influence of human disturbances on the interactions between plant and animal communities. Because ants, rodents, and birds are Cerrado’s the main seed dispersers and granivores, seedling recruitment in Cerrado landscape mosaics will depend on how these distinct but related processes are each influenced by species-specific patterns of seed size and seed abundance.     

Seasonal variation in the metabolism-temperature relation of House Sparrows (Passer domesticus) in KwaZulu-Natal,South Africa

Many birds exhibit considerable phenotypic flexibility in metabolism to maintain thermoregulation or to conserve energy. This flexibility usually includes seasonal variation in metabolic rate. Seasonal changes in physiology and behavior of birds are considered to be a part of their adaptive strategy for survival and reproductive success. House Sparrows (Passer domesticus) are small passerines from Europe that have been successfully introduced to many parts of the world, and thus may be expected to exhibit high phenotypic flexibility in metabolic rate. Mass specific Resting Metabolic Rate (RMR) and Basal Metabolic Rate (BMR) were significantly higher in winter compared with summer, although there was no significant difference between body mass in summer and winter. A similar, narrow thermal neutral zone (25–28 °C) was observed in both seasons. Winter elevation of metabolic rate in House Sparrows was presumably related to metabolic or morphological adjustments to meet the extra energy demands of cold winters. Overall, House Sparrows showed seasonal metabolic acclimatization similar to other temperate wintering passerines. The improved cold tolerance was associated with a significant increase in VO₂ in winter relative to summer. In addition, some summer birds died at 5 °C, whereas winter birds did not, further showing seasonal variation in cold tolerance. The increase in BMR of 120% in winter, compared to summer, is by far the highest recorded seasonal change so far in birds.     

Estimation and management of genetic diversity in small populations of plains zebra (Equus quagga) in KwaZulu-Natal, South Africa

Plains zebras (Equus quagga antiquorum) occur in few large, but many small, isolated populations in KwaZulu-Natal. Problems identified in small populations include reduced striping patterns on hind quarters, smaller size, elevated mortality rates and high number of still-births. Inbreeding may be implicated. Population viability analysis (PVA) was conducted with a computer model (VORTEX), and DNA and allozyme analyses were conducted to test the findings of the model. Using standard methods, DNA (PCR-RAPD) and allozyme diversity was assessed in blood samples from 72 plains zebra from four KwaZulu-Natal Nature Conservation Services (KZN-NCS) protected areas: Umfolozi Game Reserve (UGR), Albert Falls (AFNR), Vernon Crookes (VCNR) and Harold Johnson (HJNR) Nature Reserves. Populations of the latter three, small-sized (9-110 individuals) populations were seeded from the same source population (UGR: current population of 2000) during the past 25 years. Information from PCR-RAPD and allozyme analyses were compared with each other as well as to that predicted by population genetic modelling (using VORTEX). Allozyme heterozygosities were consistently high in all populations (12.1-12.9%), with no observable losses associated with reduced population size. On the other hand, percentage loss of polymorphism (20-39%) calculated from the PCR-RAPD study appeared to be positively correlated with the loss of heterozygosity predicted by population viability analysis (PVA), and negatively correlated with population size. On the basis of the above results, a policy of translocation was advocated for small, intensely managed populations of zebras, whereby a harem should be translocated every five years for a population size of nine (HJNR), while for a population size of 110 (VCNR) translocations should take place every 15 years if heterozygosity is to be maintained at more than 90% within each population over 100 years.     

Population structure of an invasive parthenogenetic gastropod in coastal lakes and estuaries of northern KwaZulu-Natal, South Africa

Background

Estuaries and coastal lakes receive little attention despite being heavily invaded by non-indigenous invasive species (NIS). In these situations, studies of population dynamics in invaded habitats can provide valuable insights into how NIS interact with new environments. Tarebia granifera is a prosobranch gastropod from south-east Asia which has invaded other sub-tropical parts of the world. This study addresses whether a small number of key environmental factors influences gastropod communities, and specifically how the population density and size structure of T. granifera were influenced by environmental change in estuaries and coastal lakes in southern Africa.

Methodology/Principal Findings

T. granifera''s density, number of brooded juveniles and size structure were measured at the St. Lucia Estuary, Mgobozeleni Estuary, Lake Sibaya and Lake Nhlange. Size structure was classified according to shell height (SH). All dissected individuals were found to be female and free from trematode infection. Salinity, water depth, temperature, and pH were the main factors correlated with population density of gastropod communities. T. granifera often reached densities well over 1000 ind. m⁻², displacing indigenous gastropods and becoming a dominant component of the benthic community. T. granifera successfully invaded estuaries despite frequent exposure to high salinity and desiccation, which could together eliminate >97% of the population. The persistence of T. granifera was ensured due to its high fecundity and the environmental tolerance of large adults (20–30 mm SH) which carried an average of 158±12.8 SD brooded juveniles. Repeat introductions were not essential for the success of this parthenogenetic NIS.

Conclusion/Significance

There is a need for a broader study on the reproductive biology of T. granifera (including the previously overlooked “brood pouch ecology”), which affects population dynamics and may be relevant to other parthenogenetic NIS, such as Melanoides tuberculata and Potamopyrgus antipodarum.