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Patch grazing of Tall Grassveld by cattle after a spring burn
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: CD MorrisPatterns of herbage removal by rotationally stocked cattle (at a density of 4.85AUE ha-1) on initially structurally homogenous Tall Grassveld were examined over a single season. Three unreplicated camps were stocked early (29 days), at the recommended '10-15cm' sward height... -
Soil fertility management in pasture small-plot trials: potential pitfalls
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: N. Miles M.B. HardySmall-plot cutting trials are of particular importance in research relating to intensive pastures. Undetected changes in soil fertility during the course of experimentation may detract from the validity of results in trials of this kind. Information from field trials conducted... -
Spatial variability in macroinvertebrate assemblages: comparing regional and multivariate approaches for classifying reference sites in South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HelenF DallasSpatial variability in macroinvertebrate assemblages was examined with the aim of evaluating the utility of regional classification systems in aquatic bioassessment. Sampling was undertaken at reference sites in the Western Cape and Mpumalanga, South Africa, using the rapid bioassessment method... -
Modelling highly variable daily maximum water temperatures in a perennial South African river system
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: NicholasA Rivers-Moore CarelN Bezuidenhout GrahamPW JewittThirty-three months of observed hourly water temperatures were used to calculate daily maximum water temperatures for nine sites within the Sabie-Sand River system, Mpumalanga Province, South Africa. A suite of statistical models for simulating daily maximum water temperatures, of differing... -
Macroinvertebrates associated with two submerged macrophytes, Lagarosiphon ilicifolius and Vallisneria aethiopica, in the Sanyati Basin, Lake Kariba, Zimbabwe: effect of plant morphological complexity
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: C Phiri --- , Zimbabwe A Chakona --- Department of Ichthyology and Fisheries Science, South Africa JA Day --- Freshwater Research Unit, Department of Zoology, South AfricaVallisneria aethiopica and Lagarosiphon ilicifolius are common and abundant submerged macrophytes in Lake Kariba, Zimbabwe. The two species have distinct structural morphologies, with Vallisneria consisting of long ribbon-like leaves, while Lagarosiphon has filiform stems with numerous small alternate leaves. This... -
Effects of crop diversity on bird species richness and abundance in a highland East African agricultural landscape
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: P Kariuki Ndang'ang'a --- , Kenya JohnBM Njoroge --- , Kenya Kamau Ngamau --- , Kenya Wariara Kariuki --- , Kenya PhilipW Atkinson --- British Trust for Ornithology, UK Juliet Vickery --- The Royal Society for the Protection of Birds, UKWe examined the effects of crop diversity on avian species richness and abundance in the highland farmlands of Nyandarua, Kenya. We surveyed birds using point counts and recorded habitat data at the same locations estimating cover and growth stage of... -
Vegetation composition and structure influences bird species community assemblages in the highland agricultural landscape of Nyandarua, Kenya
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: P Kariuki Ndang'ang'a --- BirdLife International – Africa Partnership Secretariat, Kenya John BM Njoroge --- Jomo Kenyatta University of Agriculture and Technology, Kenya Mwangi Githiru --- Ornithology Section, KenyaWe examined the effects of vegetation composition and structure on bird species diversity and richness of foraging guilds in the highland agricultural landscape of Nyandarua, Kenya. Bird point counts and vegetation surveys were undertaken during four sampling periods. Linear mixed... -
Natural markings of Cuvier's beaked whale Ziphius cavirostris in the Mediterranean Sea
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Rosso --- CIMA Research Foundation, Italy M Ballardini --- , Italy A Moulins --- CIMA Research Foundation, Italy M Würtz --- Biology Department, ItalyErrors in analysis using natural marks have been recognised since the early development of mark-recapture techniques. In this nine-year study, the mark types present on Cuvier's beaked whales Ziphius cavirostris in the Mediterranean Sea were categorised in order to assess... -
Transit station or destination? Attendance patterns, movements and abundance estimate of humpback whales off west South Africa from photographic and genotypic matching
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: J Barendse --- , South Africa PB Best --- , South Africa M Thornton --- , South Africa SH Elwen --- , South Africa HC Rosenbaum --- , USA I Carvalho --- , USA C Pomilla --- , USA TJQ Collins --- , USA MA Meÿer --- , South Africa RH Leeney --- , UKHumpback whales Megaptera novaeangliae found off west South Africa (WSA) are known to display an atypical migration that may include temporary residency and feeding during spring and summer. At a regional scale there is uncertainty about how these whales relate... -
A preliminary survey and analysis of the spatial distribution of aquatic invertebrates in the Okavango Delta, Botswana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HelenF Dallas Belda MosepeleThe spatial distribution of aquatic macroinvertebrates in the Okavango River Delta, Botswana, was investigated during the low-water period in February 2003. This complements an earlier study undertaken during high-water in June 2000. Seventy-five samples were taken in a range of... -
Intra-archipelago moult dispersion of southern elephant seals at the Prince Edward Islands, southern Indian Ocean
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: WC Oosthuizen --- Mammal Research Institute, Department of Zoology and Entomology, South Africa MN Bester --- Mammal Research Institute, Department of Zoology and Entomology, South Africa PJN de Bruyn --- Mammal Research Institute, Department of Zoology and Entomology, South Africa GJG Hofmeyr --- Mammal Research Institute, Department of Zoology and Entomology, South AfricaDuring three summer surveys at Prince Edward Island (PEI), southern Indian Ocean (2001, 2004 and 2008), 416 southern elephant seals Mirounga leonina were inspected for identification tags. In all, 42 seals that had been tagged as weaned pups at their... -
Dry season foraging preferences of cattle and sheep in a communal area of South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J Bennett PC Lent PJC HarrisWe examined landscape and habitat (vegetation) scale foraging of cattle and sheep at two communal villages in the Eastern Cape, South Africa, to determine the key resources utilised during the dry season. At the landscape scale, cattle at both sites... -
Grassland bird response to vegetation structural heterogeneity and clearing of invasive bramble
Item type: Journal Article • Journal: African Zoology • Authors: Chevonne Reynolds --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South Africa Craig T. Symes --- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South AfricaSpatial and temporal patterns of disturbance and the subsequent heterogeneity are critical in maintaining biodiversity within grassland ecosystems. Grassland birds have evolved within this ‘shifting mosaic’ to become reliant on specific habitat characteristics maintained under varying levels of both natural... -
Genetic diversity within two Tunisian wild jirds: Meriones shawi and Meriones libycus (Rodentia, Gerbillinae)
Item type: Journal Article • Journal: African Zoology • Authors: Hanene Khemiri --- Laboratory of Animal Ecology, Department of Biology, Sciences Faculty of Tunis, Tunisia João Pimenta --- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal António Amorim --- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal Pascale Chevret --- Laboratoire de Biométrie et Biologie Evolutive – UMR CNRS 5558, France Saïd Nouira --- Laboratory of Animal Ecology, Department of Biology, Sciences Faculty of Tunis, Tunisia Alexandra M Lopes --- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, PortugalThree Meriones species inhabit Tunisia, namely M. shawi, M. libycus and M. crassus, but little genetic data exist on these gerbils. We collected Meriones from eight localities in Tunisia, and obtained mitochondrial (cytochrome b) and nuclear (IRBP) gene sequence data... -
Analyses of mathematical models for city population dynamics under heterogeneity
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: O.C. Collins --- Institute of Systems Science, South Africa T.S. Simelane --- Institute of Systems Science, South Africa K.J. Duffy --- Institute of Systems Science, South AfricaIn this study, a mathematical model which takes heterogeneity into account is presented to describe city population dynamics. Initial insight is gained by qualitative analyses of a homogeneous version of this model. To understand the population dynamics of South African... -
Does defoliation frequency and severity influence plant productivity? The role of grazing management and soil nutrients
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Zander S Venter --- , Norway Heidi-Jayne Hawkins --- , South Africa Michael D Cramer --- , South AfricaRangeland management approaches, including rotational grazing, rely on assumptions about plant growth responses to the intensity, or severity (sward height) plus frequency, of defoliation. We tested these assumptions at the farm, patch and plant scale using data from a grazing... -
The impact of sustainable investment on firm performance in South Africa
Item type: Journal Article • Journal: South African Journal of Accounting Research • Authors: Vongani V. Masongweni --- University of Johannesburg, South Africa Beatrice D. Simo-Kengne --- University of Johannesburg, South AfricaPurpose: This study investigates the influence of environmental, social, and governance (ESG) scores on the financial performance of firms in South Africa across industries. -
Effect of botanical composition calibration on the accuracy of undisturbed sward height and comparative yield method techniques for herbage mass estimation in tropical heterogeneous pastures
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Diana Marcela Valencia-Echavarría --- , Colombia Yury Tatiana Granja-Salcedo --- , Colombia David Felipe Nieto-Sierra --- , Colombia Piedad Yanneth Martínez-Oquendo --- , Colombia Gonzalo de Jesús Restrepo-Castañeda --- , Colombia Lucas Esteban Cano-Gallego --- , Colombia Olga Lucía Mayorga-Mogollón --- , ColombiaThis study aimed to evaluate the influence of botanical composition calibration on the accuracy of undisturbed sward height and comparative yield method (CYM) techniques for herbage mass estimation in tropical heterogeneous pastures. Two studies were conducted using two grazing systems...