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1.
Inland salt lakes are widely distributed in southern Africa: they are particularly common in South Africa, but many occur in Namibia and Botswana. All are shallow, and most are ephemeral with salinities that are not very high (mostly < 50 g l−1). Fringing zones of halophytes or submerged macrophytes are neither well-developed nor taxonomically diverse. The Cyanobacteria, especially Nodularia spumigena, often dominate the phytoplankton. The fauna of the Makgadikgadi area (northeast Botswana) is diverse and is similar to that of East African salt lakes. The aquatic fauna of salt water south of the Makgadikgadi Basin, on the other hand, is extremely depauperate, has no well-defined assemblage confined to saline waters, and appears mostly to comprise tolerant freshwater forms. Lovenula falcifera and Metadiaptomus transvaalensis (diaptomid copepods), Moina micrura (Cladocera) and Brachionus plicatilis (Rotifera) are frequently encountered zooplankton species, a few species of insects (Anisops sp., beetles, chironomids and ephydrids) are the principal non-planktonic macroinvertebrates. Artemia ‘salina’ is occasionally present, but may be an introduced form. The avifauna, in contrast to the aquatic macroinvertebrate fauna, is rich, with the greater and lesser flamingo often common.  相似文献   

2.
One major aspect of research in forensic entomology is the investigation of molecular techniques for the accurate identification of insects. Studies to date have addressed the corpse fauna of many geographical regions, but generally neglected the southern African calliphorid species. In this study, forensically significant calliphorids from South Africa, Swaziland, Botswana and Zimbabwe and Australia were sequenced over an 1167 base pair region of the COI gene. Phylogenetic analysis was performed to examine the ability of the region to resolve species identities and taxonomic relationships between species. Analyses by neighbour-joining, maximum parsimony and maximum likelihood methods all showed the potential of this region to provide the necessary species-level identifications for application to post-mortem interval (PMI) estimation; however, higher level taxonomic relationships did vary according to method of analysis. Intraspecific variation was also considered in relation to determining suitable maximum levels of variation to be expected during analysis. Individuals of some species in the study represented populations from both South Africa and the east coast of Australia, yet maximum intraspecific variation over this gene region was calculated at 0.8%, with minimum interspecific variation at 3%, indicating distinct ranges of variation to be expected at intra- and interspecific levels. This region therefore appears to provide southern African forensic entomologists with a new technique for providing accurate identification for application to estimation of PMI.  相似文献   

3.
In order to test the hypothesis that in Central Africa variation in melanin concentration in the human skin largely results from adaptation to ultraviolet radiation, skin reflectance of the inner surface of the arm was measured at 685 nm in three samples: a sample of 415 Sara, who have a long history of habitation in the very sunny savanna of Chad; a sample of 278 Oto, a Konda caste that migrated to the equatorial forest of Zaire less than two millennia ago;and a sample of 122 Twa, a Konda caste that has been in the equatorial forest longer than the Oto. The predicted Sara-Oto-Twa sequence was confirmed and is at least partly genetically based.The study presented here is a part of an International Biological Programme/Human Adaptability Program project, which has been supported by the French and Belgian International Biological Programme committees, by Recherche Coopérative sur Programme 117 of Centre National de la Recherche Scientifique, in the Chad by Institut National Tchadien pour les Sciences Humaines, and in Zaire by Office National pour la Recherche et le Développement and Institut pour Recherche Scientifique au Congo.  相似文献   

4.
The genus Parapsylla (Homoptera: Psylloidea) is redescribed and placed in the Diaphorininae of the Family Aphalaridae. Its relationships within this subfamily are discussed. The genus Agmapsylla syn. nov. is placed into the synonymy of Parapsylla , and Pennavena syn. nov. and Eudiaphorina syn. nov. are placed into the synonymy of Diaphorina. The eight known species of Parapsylla are distributed in southern Africa and upland areas of East Africa. Host plant relationships are not clearly established but the genus appears to be associated with species of Maytenus (Celastraceae), Olinia (Oliniaceae) and possibly Olea (Oleaceae) and Syzygium (Myrtaceae). Parapsylla relicta syn. nov, and A. aureus syn. nov. are placed into the synonymy of Arytaina capensis. Parapsylla capensis comb. nov. is transferred from Arytaina, Parapsylla valens comb. nov. is transferred from Diaphorina , and the following new species are described: P. angolensis sp. nov., P. eafra sp. nov., P. huila sp. nov., P. marginipennis sp. nov., P. rufa sp. nov. and P. theroni sp. nov.  相似文献   

5.
Five new rust species are described and hitherto unknown spore states for the following seven species are reported: Puccinia desertorum on Evolvulus alsinoides, Uromyces comptus on Merremia bipinnatipartita, Puccinia halsei on Acacia hereroensis, Ravenelia transvaalensis on Acacia mellifera, Puccinia abutili on Abutilon angulatum, on Abutilon cf. austroafricanum, and on Abutilon cf. rehmannii, Puccinia lycii on Lycium sp. and Puccinia turgida on Lycium europaeum and on Lycium cf. oxycarpum. We also examined Uredo combreticola on Combretum cf. engleri, on Combretum hereroense, and on Combretum zeyheri, Puccinia afra on Lycium sp., and Uredopeltis cf. chevalieri on Grewia flavescens. All mentioned rust fungi are described in detail and are shown by line drawings. Selected species are illustrated with SEM-photographs. Part 220 in the series “Studies in Heterobasidiomycetes” from the Botanical Institute, University of Tübingen  相似文献   

6.
Rust fungi on Aizoaceae in southern Africa have been examined and reported based on 27 specimens collected during a biodiversity study and previously collected herbarium specimens. Eight species including five new species have been recognized, and they are described in detail and illustrated. Together with two additional species in literature, ten species of rust fungi are now recognized on Aizoaceae in southern Africa. Part 223 in the series “Studies in Heterobasidiomycetes” from the Botanical Institute, University of Tübingen.  相似文献   

7.
The rust mycobiota (Uredinales, Basidiomycota) of southern Africa (Botswana, Namibia, and South Africa) is analysed with regard to species richness, generic composition, and similarities to the rust mycobiotas of the remaining African continent and other regions of the world. Southern Africa is home to about 546 rust species: ca 522 species have been reported from South Africa, 73 from Namibia, and less than ten from Botswana. Thirty-two species were considered to be exotics. Two hundred and twenty-five of the species are restricted to southern Africa, suggesting an endemism rate of ca 44 %. At present, the rust fungus:host ratio is 1:38.5, which is much lower than expected from other regions of the world. This low ratio may partly be due to under-exploration of the area, but the results presented here indicate that a natural paucity of rust fungi on certain, especially species-rich plant taxa centred in southern Africa and possibly environmental factors are more important reasons. The predominant genera are Puccinia and Uromyces accounting for ca 59 % of the rust species. The genera Hemileia, Phakopsora and especially Ravenelia, centred in tropical regions, are well represented and sum up to 8 % of the species. Members of Melampsoraceae and Phragmidiaceae, common in temperate regions of the Northern Hemisphere, are scarce. Most of the other 28 recorded teleomorph genera are only represented by three or less species. In an African context, most species are shared with central and east Africa (almost 16 %). Only a few species are disjunct between southern and West Africa or Madagascar. Ca 10 % of the species are shared only with other parts of the paleotropics, especially the Indian subcontinent. Disjunctions of native species with the New World, Australia/New Zealand, or Europe are rare.  相似文献   

8.
This paper explores the grazing management systems in operation in communal areas of central Eastern Cape Province, South Africa, through two contrasting case studies from the region. Considerable differences in current management systems are identified and are shown to depend primarily on the degree of control that can be exercised by communities over communal grazing resources. This in turn can be related to the social and ecological heterogeneity that characterises the region and how this influences pressure on grazing resources at the local level. On the basis of this study three broad levels of grazing management system are identified in these communal areas. These are: complete lack of management with grazing taking place in an ‘open-access’ manner; grazing being controlled on a community basis and grazing taking place on private land and being controlled entirely by the landowner. Many aspects of these scenarios find reflection in struggles over common property which are taking place in other parts of Africa. Understanding the variation in these systems from both a social and ecological perspective will be fundamental in challenging previous management paradigms, and facilitating the development of effective common property institutions for grazing management systems in communal areas of South Africa.  相似文献   

9.
I study the relation between orphanhood and fertility patterns in young adults using a longitudinal survey from the city of Cape Town, South Africa. The data set combines two survey waves with a year-by-year life history calendar that records key outcomes (e.g., schooling, work, fertility). It also provides information on so-called ‘parental investments’ (time and material support), family background, and literacy and numeracy test scores. I find that orphans exhibit significantly higher rates of teenage pregnancy. In particular, teenage motherhood is 19% points more likely among (female) orphans. These results suggest that orphanhood may leave a long-lasting ‘imprint’ in terms of premature fertility, especially in teenage females.  相似文献   

10.
A genealogical concordance approach was used to delineate strains isolated from Acacia dealbata and Acacia mearnsii root nodules in South Africa. These isolates form part of Bradyrhizobium based on 16S rRNA sequence similarity. Phylogenetic analysis of six housekeeping genes (atpD, dnaK, glnII, gyrB, recA and rpoB) confirmed that these isolates represent a novel species, while pairwise average nucleotide identity (ANIb) calculations with the closest type strains (B. cosmicum 58S1T, B. betae PL7HG1T, B. ganzhouense CCBAU 51670 T, B. cytisi CTAW11T and B. rifense CTAW71T) resulted in values well below 95–96%. We further performed phenotypic tests which revealed that there are high levels of intraspecies variation, while an additional analysis of the nodA and nifD loci indicated that the symbiotic loci of the strains are closely related to those of Bradyrhizobium isolates with an Australian origin. Strain 14ABT (=LMG 31415 T = SARCC-753 T) is designated as the type strain of the novel species for which we propose the name Bradyrhizobium xenonodulans sp. nov.  相似文献   

11.
The skull of a small anomodont therapsid, from the Tapinocephalus Assemblage Zone (Abrahamskraal Formation, Beaufort Group, Upper Permian) in Northern Cape Province, South Africa, represents a new basal dicynodont and is described in detail. Colobodectes cluveri gen. et sp. nov. is distinguished from other dicynodonts by an anteroposteriorly extensive caniniform process, parietals that were broadly overlapped posterolaterally by posterodorsal processes of the postorbitals, diverging anterior palatal ridges, and a dorsoventrally low foramen magnum. A phylogenetic analysis indicates that Colobodectes is the basalmost member of a dicynodont clade that excludes Eodicynodon . This position is not particularly strong, as two additional steps are needed to make Colobodectes and Eodicynodon oosthuizeni exchange places on the most parsimonious tree. Another discovery of the phylogenetic analysis is that there is little basis for recognizing Eodicynodon oelofseni as the closest relative of E. oosthuizeni . The former species is identified as the sister taxon of a clade that includes the latter and all other dicynodonts.  相似文献   

12.
African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified 22 vegetation types (six savannas, two swamp forests, 14 forest types) improving existing vegetation maps. Among forest types, we showed strong variations in stand structure and deciduousness, identifying (i) two blocks of dense evergreen forests located in the western part of the study area and in the central part on sandy soils; (ii) semi-deciduous forests are located in the Sangha River interval which has experienced past fragmentation and human activities. For all vegetation types enhanced vegetation index profiles were highly seasonal and strongly correlated to rainfall and to a lesser extent, to light regimes. These results are of importance to predict spatial variations of carbon stocks and fluxes, because evergreen/deciduous forests (i) have contrasted annual dynamics of photosynthetic activity and foliar water content and (ii) differ in community dynamics and ecosystem processes.  相似文献   

13.
Hooded Vulture Necrosyrtes monachus populations have declined dramatically in recent years, but we know little about their ecology. We radio-tagged four vultures in northern Botswana to gather data on animal movement and home-range patterns. Hooded Vultures were primarily sedentary at night. Hooded Vultures moved similar distances and speeds during the wet and dry season, and travelled over similar home ranges as measured using minimum convex polygons (MCP), but used much smaller core areas during the dry (breeding) season. We found significant differences in mean distances and speeds moved among different birds, and when comparing day to night, but not between the wet (non-breeding) and dry (breeding) season or by year. All of the variables we tested, including individual vulture differences, season, year and number of fixes, significantly influenced 95% MCP and kernel density estimate (KDE) home-range sizes. Hooded Vultures used significantly smaller KDE home-range sizes during the dry (breeding season) than in the wet (non-breeding) season. Hooded Vultures travelled smaller daily distances over smaller home ranges than most other vulture species for which data exist.  相似文献   

14.
Additional fossil Theropithecus remains, recovered from mid to late Pleistocene deposits near Hopefield , South Africa, include portions of the jaws of at least five individuals. Extensive comparisons with fossil Theropithecus from other African sites, including Makapan , Swartkrans , Kanjera , Olorgesailie , and Olduvai , reveal few morphological differences, especially when variation in modern gelada baboons ( Theropithecus gelada ) and savannah baboons (Papio) is considered. The most pronounced differences between fossil forms are overall size and relative P3 length. However, these traits do not separate the fossil forms either chronologically or geographically. Other traits, such as depth of the fossa of the mandibular corpus, slope of the upper symphyseal shelf, and variation in the depth of the mandibular corpus, do not distinguish alleged primitive forms ( Makapan and lower beds at Olduvai ) from remains found at Hopefield , Swartkrans , Kanjera , Olorgesailie , Olduvai Bed IV, or the lower Ndutu Beds. Other traits, such as canine crown height and incisor size, are poorly documented for fossil Theropithecus . Thus, the available evidence suggests that Theropithecus darti and its successional species, T. oswaldi , can best be considered as a single fossil species, T. oswaldi , of which the remains from Hopefield are a late representative. Furthermore, lack of morphological differences dictates that Hopefield Theropithecus not be considered a distinct subspecies. Variation within the Hopefield sample shows that only one taxa is found at this site. Hypothesized physical and climatic conditions at Hopefield during the Pleistocene suggest that T. oswaldi lived near vleis or fresh water lagoons. Comparisons with modern T. gelada suggest a graminivorous diet for the fossil form.  相似文献   

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18.
Southern Africa's subtropical forest biome, though small and highly fragmented, supports much of the region's biodiversity. With limited resources available for conservation and the exploitative use of forest escalating, identifying a network of priority forest reserves is important. We examine the distribution of forest birds, butterflies and mammals in KwaZulu-Natal, South Africa. Using an iterative algorithm we explore the efficiency of existing protected areas, species richness and rarity hotspots, prime forest sites (selected by forest area) and complementary networks as alternative approaches to priority reserve selection, as well as the potential use of indicator taxa. Existing protected areas represent 98% of species but are relatively inefficient in terms of area. Alternative selection criteria represent a high proportion of species (86–92%) and provide efficient bases for developing fully representative reserve networks. All species are represented within a network of 22 complementary quarter degree cells. This network includes several larger forests and existing protected areas and is recommended for priority conservation. Complementary networks identified separately for birds, butterflies and mammals overlap little, but each represents a high proportion of the remaining taxa, supporting their potential as representative 'indicator' taxa. The evolutionary history of the three main forest types in KwaZulu-Natal explains observed spatial patterns of alternative reserve networks. Priority areas are concentrated in scarp and coastal forest belts, regions of comparatively recent evolutionary activity with high species richness. Afromontane forest is older and less diverse, but its inclusion in any reserve network is necessary for the full representation of forest diversity.  相似文献   

19.
《Journal of bryology》2013,35(4):304-306
Abstract

A new species of Crossidium (Pottiaceae, Bryophyta), C. karoo, is described for South Africa. It uniquely differs from congeners in tight encapsulation of the photosynthetic filaments by the clasping upper lamina.  相似文献   

20.
The taxonomy and distribution of Azolla species in southern Africa   总被引:2,自引:0,他引:2  
The three Azolla species which occur in southern Africa, A. pinnata var. pinnata, A. nilotica and A. filiculoides are identified and their distributions illustrated. The endosymbiotic cyanobacterium Anabaena azollae occurred in dorsal leaf lobe cavities of all three species. The first two species are indigenous to southern Africa, whilst the third, A. filiculoides , is an introduced species from North America. Possible means whereby this species could have been introduced are discussed.  相似文献   

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