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Assosiasie van Cymbopogon plurinodis met klei‐inhoud van grond in die Suuragtige‐Gemengde Bosveld1
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: G.N. Smit --- Departement Plantproduksie, Republiek van Suid‐Afrika N.F.G. Rethman --- Departement Plantproduksie, Republiek van Suid‐AfrikaAssociation of Cymbopogon plurinodis with the day content of soil in the Sourish Mixed Bushveld. In a camp, typical of the Sourish Mixed Bushveld, a marked decrease in the abundance of Cymbopogon plurinodis along a soil gradient from high to... -
A multivariate approach to the response of lucerne plants to varying soil conditions in pots
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: G.R. Barnes --- Department of Agricultural Development, Republic of South AfricaFive levels of lime, five levels of P and a constant level of K were applied to soil in pots to create a range of soil conditions. Factor analysis was used to relate a number of soil test variables to... -
Measurement of water potential in the trunks of citrus trees using screen-caged thermocouple Psychrometers
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: D.M. Oosterhuis --- Department of Agronomy, U.S.A. M.J. Savage --- Department of Soil Science and Agrometeorology, Republic of South Africa H.H. Wiebe --- Biology Department, U.S.A.Screen-caged thermocouple Psychrometers were used to non-destructively measure the water potential (ψ) in the trunks of mature citrus trees (Citrus sinensis L. Osbeck), and the values compared with the ψ of covered, exposed, and shaded leaves of the same tree... -
UNDERSTANDING THE PHYSICAL STRUCTURE OF SOUTHERN AFRICA'S STANDING WATERS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: B.R. Allanson --- , South AfricaAn examination of the nature of the stratification in polymictic and monomictic Southern African reservoirs is presented. Wind stirring is the principal mode of heat transfer during spring heating. In high summer radiation from stable heated surface layers is responsible... -
TURBIDITY GRADIENTS IN TWO INDO-PACIFIC ESTUARIES AND THEIR INFLUENCE ON FISH DISTRIBUTION
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: D.P. Cyrus --- Coastal Research Unit of Zululand, Department of Zoology, South AfricaResearch undertaken in two widely separated estuaries in the Indo-Pacific, showed that both have distinct turbidity gradients. In the turbid St Lucia System, on the South East Coast of Africa (range 2 to 568 Nephelometric Turbidity Units (NTU)), different turbidity... -
A comparison of the effects of different rangeland management systems on plant species composition, diversity and vegetation structure in a semi-arid savanna
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: M Smet D WardMost of South Africa's land surface is arid or semi-arid rangeland. Three management systems exploit these areas: commercial livestock ranching, communal livestock ranching and game ranching. The ways in which these management systems affect rangeland ecology is contentious due to... -
Species responses to grazing in the Smaldeel area of the Eastern Cape1
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: J.C. Martens --- , Republic of South Africa J.E. Danckwerts --- , Republic of South Africa P.J.K. Zacharias --- Department of Grassland Science, Republic of South AfricaSpecies composition of the grass layer was measured in plots selected to cover a wide spectrum of condition states in six range types. This was achieved by placing 257 sample plots along contrasting fence‐lines in adjacent plots on either side... -
Fish assemblages in relation to environmental gradients along a small west African coastal basin, the San Pedro River, Ivory Coast
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: T Koné GG Teugels V N'Douba EP Kouamélan G Gooré BiPatterns of fish population composition were examined in the San Pedro River, Ivory Coast, in 2001 to assess whether distinct types of assemblage exist along longitudinal gradients within this small coastal basin. A total of 45 species was found: 28... -
Fish communities along environmental gradients within the Comoé River basin, Côte d'Ivoire
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: StanislasS Yao EssetchiP Kouamélan Tidiani Koné Valentin N'Douba Gooré Bi Frans Ollevier DirkF E Thys van den AudenaerdeEighty-four sites in the Comoé basin (Côte d'Ivoire, West Africa) were sampled to identify fish assemblages and their relationships with some environmental variables. Seventy-six freshwater fish species were collected from 22 families and 44 genera: 11 marine and/or brackish water... -
Water quality assessment and application of the biological diatom index in the Kebir-East wadi, Algeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: N Chaïb --- Laboratoire de Recherche et de Conservation des Zones Humides, Algeria J Tison-Rosebery --- Cemagref Bordeaux, FranceA total of 118 benthic diatom taxa were recorded during a survey in 2007 of the Kebir-East wadi, north-eastern Algeria. Fourteen samples were collected at seven sampling stations in winter and summer. The majority of diatom taxa comprised cosmopolitan species... -
The community composition and biomass of pelagic ciliated protozoa in East African lakes
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AndrewW Yasindi WilliamD Taylor DenisH LynnThe community composition and biomass of planktonic ciliates were studied in 17 tropical East African lakes varying from freshwater to saline, and from oligotrophic to eutrophic. The conductivity of the lakes varied from 207μS cm−1 to 70 000μS cm−1. Chlorophyll... -
Water location, piospheres and a review of evolution in African ruminants
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: JF Derry AJ DougillThe main radiation of large mammalian herbivores in Africa took place in the Pliocene–Pleistocene, when a long-term trend towards aridification promoted grasslands and the diversification of ruminant grazers. Traditional models of this evolution identify habitat fragmentation in response to climate... -
Impact of marine inundation after a period of drought on the lakeshore vegetation of Lake St Lucia, South Africa: resilience of estuarine vegetation
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: EJJ Sieben --- Department of Plant Sciences, South Africa WN Ellery --- Department of Geography, South Africa BW Dullo --- Center for Energy and Environmental studies, The Netherlands AP Grootjans --- Center for Energy and Environmental studies, The NetherlandsThe shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded... -
Impact of livestock grazing intensity on plant diversity of montane grassland in the northern Drakensberg, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: TA Shezi --- , South Africa TG O’Connor --- , South Africa ETF Witkowski --- , South AfricaCommunal livestock grazing is expected to impact botanical composition and plant diversity of Drakensberg montane grasslands. Accordingly, a grazing gradient extending outward from kraals, and fence-line contrasts between communal rangeland and protected areas (Golden Gate Highlands National Park and Royal... -
Changes in plant vegetation structure and diversity with distance from herder shelters in the Middle Atlas Mountains
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: A El Aich --- Institut Agronomique et Vétérinaire Hassan II, Morocco S Ghassan --- Institut Agronomique et Vétérinaire Hassan II, Morocco CL Alados --- Instituto Pirenaico de Ecología (CSIC), Spain S El Aayadi --- Institut Agronomique et Vétérinaire Hassan II, Morocco L Baamal --- Institut Agronomique et Vétérinaire Hassan II, MoroccoLivestock grazing intensity gradients associated with sheep holder shelters influenced the longevity of rangelands vegetation. This study aimed to examine the effects of livestock grazing pressure on vegetation structure and diversity with distance from herder shelters. Six shelters were sampled...