Articles by Keyword: Intraspecific Variability

Search results for Intraspecific Variability

We found 47 results for you
  1. Intraspecific variability: an important consideration in forming generalisations about toxigenic algal species

    Intraspecific variability: an important consideration in forming generalisations about toxigenic algal species

    Item type: Journal Article • Journal: African Journal of Marine Science
    Intraspecific variability (strain differences) in key characteristics such as life-history traits, behaviour, nutrition, genetics and toxicity, has been experimentally documented for many toxigenic microalgae, including species of cyanobacteria, dinoflagellates, haptophytes, raphidophytes and diatoms. This paper summarises findings from published studies...
  2. Changing perceptions of fire management in savanna parks

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Parks are managed to preserve their pristine state. Fire has had a varied role in this, depending on shifting paradigms of savanna functioning. Formerly, an equilibrium theory of functioning prevailed where fire was at first an unavoidable evil, and then...
  3. Spatial variability of two selected soil properties in a semi- arid subcatchment of the Lower Great Fish River

    Spatial variability of two selected soil properties in a semi- arid subcatchment of the Lower Great Fish River

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The variability of the soluble salt content and the textural composition of the soil were investigated in a 28-ha sub-catchment of the Ecca River, a tributary of the Great Fish River. The frequency distribution of the soluble salts in the...
  4. Characterizing the hydraulic properties of a semi-arid catchment by means of sorptivity measurements and scaling theory

    Characterizing the hydraulic properties of a semi-arid catchment by means of sorptivity measurements and scaling theory

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The variability of soil sorptivity within a semi-arid catchment was investigated on a macro- (28 ha) and microscale (16 m2). In the macroscale study, sorptivity was measured at 176 sites using a falling hydraulic head technique. The mean sorptivity of...
  5. The genetic variability of malt quality and related characteristics in grain sorghum

    The genetic variability of malt quality and related characteristics in grain sorghum

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The inheritance of and relationships between diastatic power, seed texture, steep mass, malt mass, dry malt mass, rate of moisture uptake during malting and percentage moisture of malt were analysed by means of a factorial crossing design, which involved the...
  6. Temporal and spatial relations of plant element uptake and yield of a lucerne stand

    Temporal and spatial relations of plant element uptake and yield of a lucerne stand

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    In general, agricultural fields are managed as uniform units, ignoring spatial and temporal relations between plant element uptake and yield. This study was conducted from June 2001 to February 2002 on a two-year-old lucerne stand and explores the spatial relationships...
  7. Spatial variation of soil and plant properties and its effects on the statistical design of a field experiment

    Spatial variation of soil and plant properties and its effects on the statistical design of a field experiment

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The standard procedure in field experimentation is to use a randomized complete block (RCB) design, striving for the most homogeneous conditions as possible among plots in the same block. However, geostatistical concepts dictate that a spatial dependence exists for observations...
  8. A rapid demonstration of the self-thinning rule using radish

    A rapid demonstration of the self-thinning rule using radish

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The self-thinning rule describes the relationship between individual mass and density in crowded evenly-aged plant populations in which the slope of the relationship is always greater than -1. This study investigated whether the rule could be demonstrated in six weeks...
  9. Perceptions of climate change and barriers to adaptation amongst commonage and commercial livestock farmers in the semi-arid Eastern Cape Karoo

    Perceptions of climate change and barriers to adaptation amongst commonage and commercial livestock farmers in the semi-arid Eastern Cape Karoo

    Item type: Journal Article • Journal: African Journal of Range & Forage Science
    Climate change is expected to adversely affect agriculture in South Africa. A rise in variable and unfavourable conditions is likely to surpass the limits of current coping mechanisms of farmers, compelling them to implement more resilient adaptive measures to decrease...
  10. Seasonal variability of macroinvertebrate assemblages in two regions of South Africa: implications for aquatic bioassessment

    Seasonal variability of macroinvertebrate assemblages in two regions of South Africa: implications for aquatic bioassessment

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Seasonal variability of macroinvertebrate assemblages was examined in two regions of South Africa: Western Cape and Mpumalanga. Sampling was undertaken at reference sites using the rapid bioassessment method SASS4 (South African Scoring System, Version 4). This study examined the influence...