Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

Application of a multidisciplinary approach to the systematics of Acomys (Rodentia : Muridae) from northern Tanzania

Abstract: The systematic status and geographic distribution of spiny mice of the genus Acomys I. Geoffroy, 1838 in northern Tanzania is uncertain. This study assesses the systematic and geographic distribution of Acomys from northern Tanzania using a multidisciplinary approach that includes molecular, cytogenetic, traditional and geometric morphometric analyses, and classical morphology of the same individuals. The molecular analysis was based on 1140 base pairs (bp) of the mitochondrial cyt...

Soil invertebrate pests in the re-establishment of plantations in South Africa

Abstract: Please read the abstract provided for each separate chapter and the General Summary (Chapter 9) added to the section 00front

Systematics of Trogidae (Coleoptera) : new South African species, and a molecular phylogeny of the family

Abstract: At its inception, taxonomy simply provided guidelines for nomenclature. It has since developed into a science applied to problems relating to economics, conservation and even law. Taxonomy is arguably one of the most important pillars of the biological sciences, providing the framework from which all other studies are conducted. We expand this essential foundation by describing four new species of Trox in Chapter 2 of this dissertation - the first to be recorded in South Africa sin...

A systematic appraisal of the Eriophyoidea (Acari Prostigmata)

Abstract: The diversity of the Eriophyoidea is largely unknown and their systematic study mostly entails alpha-taxonomy which is critically important for these mites. Eriophyoid morphology is almost exclusively studied on slide-mounted specimens, and truly permanent specimen slides cannot be prepared and are eventually lost. Shortcomings in taxon descriptions are persistent, and too few morphological characters are available for systematic use, particularly for phylogenetic studies. The frag...

Local and regional factors influencing dung beetle assemblage structure across an environmental gradient in Botswana

Abstract: The taxonomic composition, structure, and diversity of current local species assemblages results from an interacting complex of historical, regional ecological and local ecological factors. Structural differences between such current species assemblages are primarily determined by changing ecological conditions across spatial gradients. These conditions may change abruptly or they may represent a gradual divergence. Across the Botswana Kalahari basin there is a gradual northeast-so...

The influence of maternal protein intake on aspects of sex-specific foetal and neonatal development in Mastomys Natalensis

Abstract: Captive multi-mammate mice, Mastomys natalensis, were paired and kept on one of three treatment diets (low, medium and high protein) in order to assess differential maternal investment in the sexes, and sex-specific resource allocation of offspring. The influence of maternal dietary protein content on maternal reproductive performance, sex-specific body composition of pups and pup growth from birth to weaning was determined. Mothers on the high protein diet were larger than those o...

The influence of supplementary food on the rodent communities of coastal sand dunes

Abstract: The present study arrived at investigating the influence of supplementary food on a developing rodent community on the coastal dune forests north of Richards Bay, South Africa. Four sites were selected for the field experiment. Each of these study sites comprised a treatment and control grid. Sunflower seeds were provided on the treatment grids and the response thereof on rodent population and community variables were measured. Each of the grids were trapped on a monthly bases as t...

Mapping bugweed (Solanum mauritianum) infestations in Pinus patula plantations using hyperspectral imagery and support vector machines

Abstract: The invasive plant known as bugweed (Solanum mauritianum) is a notorious invader of forestry plantations in the eastern parts of South Africa. Not only is bugweed considered to be one of five most widespread invasive alien plant (IAP) species in the summer rainfall regions of South Africa but it is also one of the worst invasive alien plants in Africa. It forms dense infestations that not only impacts upon commercial forestry activities but also causes significant ecological and en...

Physiological diversity in insects : large scale patterns

Abstract: Please read the abstract in the section 00front of this document

The impact of climate change and variability on tomato (Licopersicon esculentum) production in the Limpopo Province, South Africa

Abstract: The Limpopo Province is a major tomato growing region in South Africa, producing 66% of the total annual tonnage of tomatoes. The Limpopo Province is particularly vulnerable to the impact of climate change, partly because it is exposed to extreme weather events. According to the Intergovernmental Panel on Climate Change (IPCC) Africa will be hit hardest by climate change as larger areas could be stricken by yield decreases of over 50% by the year 2020 because of an increasingly hot...

Effects of certain anthelmintics on the survival and reproduction of Euoniticellus intermedius (Reiche) (Coleoptera : Scarabaeidae)

Abstract: Avermectins and milbemycins are commonly used in agro-ecosystems for the control of parasites in domestic livestock. As integral members of agro-ecosystems with importance in maintaining pasture health through dung burial behaviour, dung beetles are an excellent, non-target, bio-indicator taxon for examining potential detrimental effects of pesticide application. The current study uses the dung beetle species, Euoniticellus intermedius (Reiche), as a bio-indicator to test the relat...

The Population dynamics of Rodents at Pongola, Northern Zululand, exposed to Dieldrin coverspraying

Abstract: Four grids, each 3,42 ha (4 morgen) in size, were live trapped from April 1967 through May 1969 in two soil and vegetation types (black turf~ Acacia nigrescens community, and brown reddish soil: Acacia tortilis community) at Pongola, northern Zululand, to determine the effect of dieldrin coverspraying, at a dosage of 87,4 g/hectare (2,64 oz/morgen), on rodents. Low population numbers before and especially at the time of spraying made clear-cut conclusions impossible to reach. Roden...

Biodiversity in human-modified landscapes : case studies, the state of research, and implications for conservation

Abstract: Protected areas (PAs) cover 12.9% of Earth’s land, while just 5.8% has strict protection for biodiversity (Earth’s variety of ecosystems, species, and genetic variation). Constraints of size and configuration, mismanagement, anthropogenic pressure, and climate change hamstring the capacity of PAs to conserve biodiversity. Increasingly, studies of biodiversity in human-modified landscapes provide an evidence base to support policies to make land outside of PAs as amenable as pos...

Organic matter contribution of ameliorants to reclaimed surface-mined soil and carbon storage

Abstract: Coal mining in South Africa is renowned for large scale removal of topsoil and subsoil through opencast mining. Such processes lead to an enormous amount of land degradation and thus, limit the land capability after mine closure. The removal and stockpiling of topsoil leads to adverse effects not only on the fertility of the soil but also the physical properties of the soil which greatly limit the ability of the soil to sustain plant development. Resultant mined soils have a varied...


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