Articles by Keyword: Size Selectivity

Search results for Size Selectivity

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  1. Population parameters and exploitation rate of <em>Sarotherodon galilaeus galilaeus</em> (Cichlidae) in Lakes Doukon and Togbadji, Benin

    Population parameters and exploitation rate of <em>Sarotherodon galilaeus galilaeus</em> (Cichlidae) in Lakes Doukon and Togbadji, Benin

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Growth, mortality, recruitment and relative yield per recruit of Sarotherodon galilaeus galilaeus from Lakes Doukon and Togbadji were studied. Data on total length, total weight and sex were recorded on a monthly basis between January and December 2013 for S...
  2. Benthic freshwater nematode community dynamics under conditions of Tilapia aquaculture in Egypt

    Benthic freshwater nematode community dynamics under conditions of Tilapia aquaculture in Egypt

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Studies of the influence of fish aquaculture on benthic freshwater nematode assemblages are scarce, but could provide a way of gauging environmental effects. The abundance and diversity of nematode assemblages in response to Oreochromis niloticus aquaculture were investigated in Kafr...
  3. Floristic and Structural Composition of Wonderwoud Forest in the Wolkberg, North-Eastern Transvaal

    Item type: Journal Article • Journal: South African Forestry Journal
    The closed, evergreen forest of 450 ha was studied by means of a survey of 55 circular plots of 0,04 ha, distributed in a grid pattern. TWINSPAN classification separated the forest into four stand types: Olea capensis macrocarpa—Xymalos monospora—Syzygium gerrardii...
  4. Floristic and Structural Composition of Hanglip Forest in the Soutpansberg, Northern Transvaal

    Item type: Journal Article • Journal: South African Forestry Journal
    The closed, evergreen forest of 363 ha was sampled by means of 62 circular plots of 0,04 ha, distributed in a grid pattern. TWINSPAN classification separated the forest into regrowth forest with two forest types, and mature forest with four...
  5. An evaluation of the economic viability of commercial pastoralism in the <em>smaldeel</em> area of the Eastern Cape

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Carrying capacity models and financial data from study group farmers were used to derive attainable net revenue per ha on veld in good, moderate and poor condition. From these data, minimum farm sizes required for a reasonable standard of living...
  6. Patterns of defoliation in four‐ and eight‐paddock grazing systems

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Patterns of defoliation of the dominant palatable species in a recommended eight‐paddock system and a four‐paddock system with the same grazing cycle were monitored by repeated observations of marked tillers. In the two systems, the percentages of palatable species grazed...
  7. Grass species selection patterns on rotationally‐grazed Dohne Sourveld during autumn and early winter

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally‐grazed Dohne Sourveld, at four different stocking rates. Only the most abundant grass species in the sward were monitored. Animals (cattle and sheep) grazed selectively (for plant...
  8. The relationship between sward structure, ingestive behaviour and dietary quality in cattle grazing a <em>Chloris gayana</em> pasture

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    The relationship between sward structure, ingestive behaviour (bite size, biting rate and intake rate) and dietary crude protein (CP) content was studied on a Chloris gayana pasture at different growth stages using oesopha‐geally‐fistulated steers. As the pasture matured, leaf table...
  9. Influence of rainfall and grazing on the compositional change of the herbaceous layer of a sandveld savanna

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    The influence of heavy grazing by cattle for three years, and of rainfall interception for one year, on the herbaceous composition of a sandveld savanna in Gazankulu was investigated. The composition and the abundance of the predominant species changed substantially,...
  10. Patterns of plant selection by grazing cattle in two savanna grasslands: A plant's eye view

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    The amount of grazing experienced by individual tufts of the most abundant perennial grasses of two Transvaal savannas was monitored at regular intervals for two growing seasons. In general, Setaria incrassata and Themeda triandra were heavily grazed, Bothriochloa insculpla and...