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Evaluering en kalibrering van CERES-Maize: 3. Rywydtes in die westelike Hoëveld
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A.S. du Toit --- , Republiek van Suid-Afrika J. Booysen --- Departement Plantkunde, Republiek van Suid-Afrika J.J. Human --- Departement Agronomie, Republiek van Suid-AfrikaIn die westelike-Hoëveld waar reënval die mees beperkende hulpbron is, is lae plantpopulasie en wye rye erkende produksiepraktyke vir mielies. Die praktyke verskil beduidend van die praktyke waaronder CERES- Maize ontwikkel is. Ten einde CERES-Maize te evalueer ten opsigte van... -
Measurement of radiant interception of crop canopies with the LAI-2000 plant canopy analyzer
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: N.Z. Jovanovic --- Department of Plant Production and Soil Science, Republic of South Africa J.G. Annandale --- Department of Plant Production and Soil Science, Republic of South AfricaThe performance of the plant canopy analyzer (PCA), model LAI-2000 (LI-COR, Lincoln, NE, USA), has been tested in two separate field trials for 18 annual crop and pasture species. The objective was to recommend appropriate techniques for reliable estimates of... -
Calibration and validation of the SWB irrigation scheduling model for soybean [Glycine max. (L.) Merr., indeterminate cv. Wayne]
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: N.Z. Jovanovic --- Department of Plant Production and Soil Science, South Africa J.G. Annandale --- Department of Plant Production and Soil Science, South Africa A. T.P. Bennie --- Department of Soil Science, South AfricaSoil Water Balance (SWB) is a mechanistic, irrigation scheduling, generic crop model including a database of crop specific growth parameters. The objective of this study was to calibrate and validate this model for soybean [Glycine max. (L.) Merr., indeterminate cv... -
Low genetic diversity and high genetic differentiation among severely fragmented populations of the critically endangered tree Talbotiella gentii (Fabaceae)
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: D Dompreh --- School of Biological Sciences, UK MD Swaine --- School of Biological Sciences, UK A Price --- School of Biological Sciences, UKThe genetic diversity among 17 populations (including 10 newly discovered) of Talbotiella gentii (Fabaceae, Caesalpinioideae), a rare tree species endemic to Ghana, was assessed using random amplified polymorphic DNA (RAPD). A total of 80 polymorphic bands were generated from eight... -
Do sawfish Pristis spp. represent South Africa's first local extirpation of marine elasmobranchs in the modern era?
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: BI Everett --- Oceanographic Research Institute, South Africa G Cliff --- KwaZulu-Natal Sharks Board, South Africa SFJ Dudley --- Branch: Fisheries Management, South Africa SP Wintner --- KwaZulu-Natal Sharks Board, South Africa RP van der Elst --- Oceanographic Research Institute, South AfricaLargetooth sawfish Pristis pristis and green sawfish P. zijsron were not uncommon in catches made in KwaZulu‑ Natal (KZN) on the east coast of South Africa in the mid part of the last century but apparently have disappeared from this... -
A new subfossil bulbul (Aves: Passerines: Pycnonotidae) from Rodrigues Island, Mascarenes, south-western Indian Ocean
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Julian P Hume --- Bird Group, Department of Life Sciences, UKThe Hypsipetes bulbuls (Pycnonotidae) occur on Madagascar and oceanic islands throughout the Indian Ocean, as well as continental Asia. Endemic species are found on the Mascarene Islands of Mauritius and Réunion, but the genus was purportedly never reported from Rodrigues,... -
Evaluating herbivore extinction probabilities in Addo Elephant National Park, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: M.H. Knight --- Scientific Services, South African National Parks, South Africa M. Kshatriya --- Conservation Planning Unit, Department of Zoology & Entomology, South Africa A.S. Van Jaarsveld --- Conservation Planning Unit, Department of Zoology & Entomology and Centre for Environmental Studies, South Africa A.O. Nicholls --- Division of Wildlife and Ecology, Australia A.J. Hall-Martin --- Conservation Services, South AfricaPopulation extinction evaluations, based on the model developed by Dennis et al. (1991) that did not take density dependence into account and that were based on census data, suggest that many of the herbivore species in Addo Elephant National Park... -
Trial by fire: social spider colony demographics in periodically burned grassland
Item type: Journal Article • Journal: African Zoology • Authors: Yael Lubin --- Mitrani Department of Desert Ecology, Israel Tanza Crouch --- Durban Natural Science Museum, South AfricaNature conservation authorities in southern Africa burn the grassland in nature reserves to reduce the incursion of woody plants and to encourage the growth of new grass for grazing. Studies have shown significant negative effects of burning on the abundance,... -
Ethics and extinction: Micro versus macro appropriate technology
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: C. Verharen --- Department of Philosophy, F. Bugarin --- African Studies Department, D. Schwartzman --- Department of Biology (ret.), J. Tharakan --- Department of Chemical Engineering, B. Gutema --- Department of Philosophy, Ethiopia J. Fortunak --- Department of Chemistry & Pharmaceutical Sciences, G. Middendorf --- Department of Biology, USAEthical theory and technology practice raise two primary questions. First, what are the ethical principles driving sustainable appropriate technology? Second, what are the viable applications of those principles with respect to alternative appropriate technologies? The hypothesis of this study is... -
Cape Vulture Gyps coprotheres breeding status in southern Africa: monitoring results from 2010–2014
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Kerri Wolter --- VulPro NPO, South Africa Walter Neser --- VulPro NPO, South Africa Margaret T Hirschauer --- VulPro NPO, South Africa Alvaro Camiña --- ACRENASL Environmental Consultants, SpainMonitoring of eight Cape Vulture Gyps coprotheres breeding colonies in South Africa and Botswana took place between 2010 and 2014 using standardised counting methods. Counts of breeding pairs, nestlings and fledglings were used to calculate breeding success and general population... -
Local ecological knowledge demonstrates shifting baselines and the large-scale decline of sawfishes (Pristidae) in Tanzania
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: G Braulik --- University of St Andrews, United Kingdom M Kasuga --- Wildlife Conservation Society Tanzania Program, Tanzania G Majubwa --- Ambakofi, TanzaniaSawfishes are coastally distributed rays that grow to very large sizes. All five species are assessed as Endangered or Critically Endangered as a result of population declines caused mainly by entanglements in fishing gear and by habitat degradation. Three species... -
Disease driven extinction in the wild of the Kihansi spray toad, Nectophrynoides asperginis
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Ché Weldon --- Unit for Environmental Sciences and Management, North-West University, South Africa Alan Channing --- Unit for Environmental Sciences and Management, North-West University, South Africa Gerald Misinzo --- SACIDS Africa Centre of Excellence for Infectious Diseases of Humans and Animals in Eastern and Southern Africa, Sokoine University of Agriculture, Tanzania Andrew A Cunningham --- Institute of Zoology, Zoological Society of London, United KingdomThe Kihansi spray toad, Nectophrynoides asperginis, became extinct in the wild despite population monitoring and conservation management of its habitat in the Kihansi gorge, Tanzania. Previous investigations have indicated human induced habitat modification, predators, pesticides and disease as possible causes... -
Large Pleistocene avian tracks on the Cape south coast of South Africa
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Charles W Helm --- , South Africa Martin G Lockley --- , United States Hayley C Cawthra --- , South Africa Jan C De Vynck --- , South Africa Carina JZ Helm --- , South Africa Guy HH Thesen --- , South AfricaPrior to the inception of the Cape south-coast ichnology project, only one avian tracksite had been reported from South Africa. An additonal twenty-nine sites have now been identified. Although there are limitations and challenges inherent in the study of fossil... -
Species-specific or assemblage-wide decline? The case of Arthroleptides dutoiti Loveridge, 1935 and the amphibian assemblage of Mount Elgon, Kenya
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Jacob M Ngwava --- National Museums of Kenya, Kenya Christopher D Barratt --- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Germany Elizabeth Boakes --- University College London, United Kingdom Beryl A Bwong --- National Museums of Kenya, Kenya Alan Channing --- North-West University, South Africa Olivia Couchman --- Zoological Society of London, United Kingdom Stefan Lötters --- Trier University, Germany Patrick K Malonza --- National Museums of Kenya, Kenya Vincent Muchai --- National Museums of Kenya, Kenya Julius K Nguku --- National Museums of Kenya, Kenya Joash Nyamache --- National Museums of Kenya, Kenya Nisha Owen --- On the EDGE Conservation, United Kingdom Victor Wasonga --- National Museums of Kenya, Kenya Simon P Loader --- Natural History Museum, United KingdomThe frog Arthroleptides dutoiti Loveridge, 1935, endemic to Mount Elgon, East Africa was last collected in 1962 and has not been observed since. The species is regarded as Critically Endangered by the IUCN Red List and is a priority species... -
Population Viability Analysis for a vulnerable ground-nesting species, the Cape Rockjumper Chaetops frenatus: assessing juvenile mortality as a potential area for conservation management
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Krista N Oswald --- , South Africa Alan TK Lee --- , South AfricaAs an endemic bird to the Fynbos biome, prominently featured in literature and marketing material for the avifauna of the continent, the Cape Rockjumper Chaetops frenatus is an iconic species of South Africa. Building on studies from the past decade,... -
The African Penguin Spheniscus demersus should be considered Critically Endangered
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Richard B Sherley --- Environment and Sustainability Institute/Centre for Ecology and Conservation, University of Exeter, United Kingdom Azwianewi B Makhado --- , South Africa Robert JM Crawford --- , South Africa Christina Hagen --- , South Africa Jessica Kemper --- , Namibia Katrin Ludynia --- University of the Western Cape, South Africa Makhudu J Masotla --- , South Africa Alistair McInnes --- , South Africa Lorien Pichegru --- Institute for Coastal and Marine Research, Nelson Mandela University, South Africa Desmond Tom --- , Namibia Leshia Upfold --- , South Africa Lauren J Waller --- University of the Western Cape, South AfricaThe African Penguin Spheniscus demersus has been considered a threatened species since 1984 and, aside from a short period around 2000, its population has been in constant decline since at least the 1950s. By combining counts of the numbers of...