Browsing Biological Sciences by Title
Now showing items 433-452 of 733
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'n Plantekologiese opname van Boschberg en sy omringende gebiede met spesiale verwysing na die weidingsfaktor.
(1972)No abstract available. -
Native range studies on insect herbivores associated with fireweed (Senecio madagascariensis) in KwaZulu-Natal, South Africa, with prospects for biological control in invaded countries.
(2017)Senecio madagascariensis Poir. (fireweed; Asteraceae), native to southern Africa and Madagascar, has invaded Australia, Hawaii, South America and Japan, reducing pastoral productivity and poisoning livestock. Interest in ... -
Nectar preferences of specialist and occasional avian nectarivores, and their role in the evolution of floral traits.
(2009)Our understanding of bird pollination systems has changed dramatically in the last few years. A long-standing paradigm was that hummingbirds and passerine birds select for different nectar properties in flowers ... -
Ngorongoro crater rangelands : condition, management and monitoring.
(2006)The Ngorongoro Crater is a volcanic caldera located within the Ngorongoro Conservation Area in Tanzania. The Crater comprises a flat grassland plain surrounded by steep, bushy walls. It contains extremely high densities ... -
Niche and life-history differences in five highly sympatric species of Trithemis dragonflies (Odonata: Libellulidae)
(1995)Niche and life-history differences in five species of Trithemis were investigated to determine the extent of interspecific competition. Interspecific competition was mostly avoided because species favoured different ... -
Niche modelling the distributions of large Acacia nigrescens and Sclerocarya birrea trees.
(2011)MaxEnt modelling uses only the known locations of a species to predict the overall distribution of a species. Large trees are important for the functioning of savanna ecosystems, bringing nutrients to the surface, providing ... -
Niche requirements and breeding system of Hypericum pseudohenryi, an invasive plant species in South Africa.
(2016)Invasive alien species threaten ecosystems throughout South Africa through alteration of the habitat and loss of biodiversity. Emerging invasive alien plants are those that have small populations, but have the potential ... -
The nitrogen economy of three irrigated temperate grass pastures with and without clover in Natal.
(1994)Abstract can be viewed in PDF document. -
Nitrogen fixation and cycling in Natal valley bushveld Acacia species.
(1995)Five species, Acacia karroo, A. robusta, A. nilotica, A. sieberana and A. tortilis, were inoculated with Rhizobium and grown in potted sand in a temperature controlled greenhouse. After six months, results showed a ... -
Nutrient cycling in grazing systems.
(2004)This research was conducted at the University of KwaZulu-Natal, Pietermaritzburg, South Africa. The research encompasses five different studies to assess nutrient cycling in intensive and extensive grazing systems with ... -
Occurrence and properties of the multicopper oxidases laccase and tyrosinase in lichens.
(2012)The work presented in this thesis describes the occurrence and properties of two multicopper oxidases derived from lichens. Despite numerous data on laccases and tyrosinases in fungi and flowering plants, this is the first ... -
Olfactory communication of the white rhinoceros (Ceratotherium simum)
(2017)Many mammal species communicate olfactorily via specialised scent glandular secretions, urine and/or dung. Despite a large body of work on olfactory communication, the extent to which mammals communicate via dung odours, ... -
On the behavioural ecology and vocal communication of the brown-headed parrot (Poicephalus cryptoxanthus)
(2002)The Brown-headed Parrot (Poicephalus cryptoxanthus) is a poorly known species inhabiting open woodland in south-eastern Africa. This study elucidates critical aspects of the species ecology and although each of ... -
On the ecology of hyperscum-forming Microsystis aeruginosa in a hypertrophic African lake.
(1987)Light is the primary source of energy in most of earth's ecosystems . In freshwater ecosystems the major interacting factors that determine the abundance and species composition of planktonic phototrophs, the primary ... -
On the vacuolar system in maize roots.
(1979)Root-cap cells of Zea mays L proliferate by division in the cap meristem, and subsequently differentiate and mature as they move towards the periphery of the cap, where ' they undergo autolysis and are sloughed. Vacuolar ... -
Optimal spatial and temporal utilization of grassland resources for extensive livestock production.
(2018)South Africa naturally experiences variation in rainfall patterns with distinct seasonal distribution. The anticipated disruptive effects of climate change, in this region, on vegetation dynamics is likely to accentuate ... -
Optimising methods for embryonic axis fixation and micropropagation of Syzygium cordatum Hochst.
(2009)Syzygium cordatum Hochst. (family - Myrtaceae), commonly called the umDoni (Zulu) tree, is found throughout South Africa. The tree is utilised for its fruit, bark and wood by many villagers, and this demand has placed ... -
Optimising mini-plug transplanting of Eucalyptus dunnii seedlings.
(2013)Mini-plug transplanting has only recently been described as a useful propagation method for use in forestry nurseries. Mini-plug seedlings are seedlings that have been pre-cultivated in containers with volumes less than ... -
An outline of the ecology and behaviour of the red lechwe (Kobus leche leche Gray, 1850)
(1979)In a number of publications serious concern has been expressed about 'the status of lechwe in the Kwando/Linyanti/Chobe system. Concern has also been expressed about the effects of possible water extraction from the ... -
Overcoming biological barriers to control pollinated seed production in Eucalyptus.
(2009)The overall aim of this PhD study was to develop protocols to improve the efficiency of eucalypt controlled pollinations (CPs) in order to make it more cost-effective for forestry companies to perform them on a commercial ...