Ap&es honours projects

Yüklə 68,91 Kb.
ölçüsü68,91 Kb.

Please note that some supervisors will have specific projects for you while others might advertise the field they are interested in and require you to formulate the project/design the project together. Some projects will have costs involved over and above the funds allocated by the School for honours projects. Please be aware of this and ask the supervisor if additional costs will be incurred. In addition, some projects may involve travel or field work and a driver’s licence will be required. The School does not provide drivers for field work, so please be sure to discuss logistics with your supervisor beforehand. Please speak to your potential supervisor to make sure you understand all logistics and costs before committing to a particular project.
Supervisors: Dr Ellis Ayayee and Dr E. Chivandi

Our common interest is on introduced and indigenous seeds as possible sources of nutrients in resource-challenged communities. Students with interest in chemical characterization of seeds are welcome. A project I have for 2017 is the evaluation of the seed and fruit pulp composition of Diospyros lycioides found in Johannesburg. In terms of distribution Diospyros of the family Ebenaceae, is common to the tropics and subtropics. It has several uses in various cultures in Africa including its usage as chewing sticks in Namibia (Cai et al. 2000); seeds used as a coffee substitute in parts of Gauteng and the pulp of the fruit used in making local types of beer. There are also a number of medicinal uses of the leaves and roots. Despite their wide distribution, not much is on record about the bluebushes’ anatomical features, nutritional and the chemical composition.

As part of an ongoing study, interested students will evaluate the nutritional potential of harvested fruits of Diospyros lycioides in Johannesburg, South Africa, by determining the seed’s proximate, mineral, phytate-phosphate, fibre, amino acid and fatty acid composition. For more information please contact: Ellis.Ayayee@wits.ac.za, OLS 2004
Supervisor: Prof. Kevin Balkwill

  1. Biodiversity Management Plan – Bushbuckridge Nature Reserve

Bushbuckridge Nature Reserve has been unfenced for some years. It has been passed from Conservation body to Conservation body over the last twenty years. Mpumalanga Tourism and Parks Agency are now working towards developing the area to stem the illegal harvesting that is going on. This development plan will need to take the biodiversity of the reserve as well as the needs and desires of the people who have made a land claim on the reserve into account. An exciting and challenging project!

  1. Environmental Monitoring Crocriver Mountain Conservancy

A survey was conducted of the Crocriver Mountain Conservancy (in which Pullen Farm is situated) in 2006.A number of plots were surveyed and GPS coordinates and photographs as well as data records are available. It will be most constructive to resurvey these plots and determine what differences, if any, are now evident as a result of the management of the area as well as four seasons of above average rainfall. It will also be necessary to set up monitoring plots on Pullen Farm for our future benefit.

  1. Floristics, diversity and biogeography of a serpentiniferous area

Previous studies on serpentiniferous outcrops in the Barberton Greenstone Belt have resulted in the compilation of checklists for many of the sites. There are other sites at which further collecting needs to be undertaken, and at which assessments of diversity need to be made. This project will facilitate the testing of hypotheses postulated during previous studies as well as some of the predictions that are made by the theory of island biogeography. Analyses of the distribution patterns of the species that occur at the site will provide additional phytogeographic information. A project of this nature is ideal for a part-time student, so that a full season of collecting can take place.

  1. Taxonomy - Variation in various southern African plant species

Some southern African plant species, e.g. Ipomoea oblongata, species of Barleria and species of Polygala, are highly variable. Detailed morphological studies and multivariate analyses may well show that some of these should be subdivided and that taxa need to be described as new species, subspecies or varieties.

  1. Pollination and Breeding Biology of rare, threatened or endemic plant species

We have many rare and threatened as well as narrowly endemic plant taxa in South Africa. An understanding of the pollination biology and breeding biology of such species provides vital clues to their evolution and essential data required for their conservation. There is a huge range of species to choose from. This project is probably better suited to a part-time student however, as it allows for fieldwork in the appropriate time of the year.

  1. Dispersal Mechanisms in relation to habitat preferences in the Acanthaceae

This project will involve surveying the southern African genera of the Acanthaceae to determine whether their capsules open in response to wetting or drying and comparing this to how concentrations of species of these genera correlate with different climatic zones in southern Africa. In addition, it is necessary to determine whether there is secondary dispersal in the species of Blepharis that are dispersed by epizoochory.

I am happy to discuss other projects of interest to students in fields in which I am competent to supervise. For more information please contact: Kevin.Balkwill@wits.ac.za, OLS LG 32

Supervisor: Prof. Marcus Byrne

Before discussing potential projects, I prefer students to arrive at that meeting with some ideas of their own (if possible based on topics which have included literature surveys). Ideally these should be questions of mutual interest. Some examples of basic ideas in these fields are listed below.


Tamarix occurs on the local gold mines, as a phytoremediation species. However, it hybridises to some extent with an alien species which also occurs locally. We would like to survey the insect population on Tamarix species growing close (affected be acid mine drainage) and away from the mine dumps. Since the identity of the Tamarix species in the country is now largely established, we also would like to know if insects can recognise the difference between the species, and what impact those insects have on each of the different Tamarix species. This project will be co-supervised by me and Dr. Solomon Newete.
Plant Physiology

One measure of biocontrol agent impact on a weed is to measure its effect on the physiology of its target host plant. Projects of this nature will be conducted in collaboration with Mr Nic Venter.

Dung Beetles

What do Dung Beetles eat?

Eating dung is even worse than you can imagine – it is also very low in nitrogen. How do dung beetles make a living from such awful food?

Dung Beetle Allometry

How does eye size relate to body size? What about wing size and the time of day the beetle is active? Do these link to vision and light availability? Allometry is a fascinating topic because it examines the way organisms allocate limited bodily resources to different body structures.

Ball Choice by Dung Beetles

How does a dung beetle know what a ball looks like? What key features does a dung beetle use to distinguish a dung ball from other objects in its vicinity? It isn’t the smell – that much we do know.

Other Ideas

If you have any good ideas or burning passions in the area of biological control or insect biology, I am willing to entertain the possibility of helping you use them as the basis of an Honour’s project if it falls within my area of expertise.

For more information please contact: Marcus.Byrne@wits.ac.za, Biology Building, B23
Supervisor: Prof. Marcus Byrne and Dr Solomon Newete

  1. The indigenous Artemisia afra Jacq Ex Willd. (Asteraceae) herb, which is also known as the African wormwood, is a multi-stemmed perennial clump-forming herb/shrub with fluffy silver-grey foliage that grows to a height of up to 1.5 m (Burits et al., 2001). With a wide distribution from the Cederberg Mountains in the Cape, northwards to tropical East Africa and stretching as far north as Ethiopia, it is one of the oldest and best known medicinal plants in the continent, and is still used effectively today in South Africa by people of all cultures. The roots, stems and leaves are used in many different ways and taken as enemas, poultices, infusions, body washes, lotions, smoked, snuffed or drunk as a tea. A. afra has a very bitter taste and is usually sweetened with sugar or honey when drunk. Artemisia afra has already established in the Klipriviersberg Nature Reserve (10 km from the center of the Johannesburg). Research question: 1- find its distribution within the reserve; 2-investigate the concentration of heavy metal pollutants in the plant tissues of A. afra to alert consumers of any health hazards associated as a result a result of for instance mining pollution.

  1. Another possible project could be: the indigenous perennial woody shrub, Seriphium plumosum. The genus has 36 species of which 32 are indigenous to South Africa. Amongst these S. plumosum, also known as the ‘bankrupt bush’, is recognized as one of the most aggressive encroacher in the Grassland and Savanna Biomes. It is declared as proclaimed encroacher and recommended for complete removal and control by land owners according to the CARA legislation (Regulation 16 of the Conservation of Agriculture Resources Act 43). This shrub has already established and spreading in the Klipriviersberg Nature Reserve in Gauteng designated for protection of the fast dwindling Grassland Biome. Although, S. plumosum is largely known to grow and spread from seeds it would be interesting to survey its extent of distribution in the Reserve, its seed viability and if vegetative growth is another means of potential spread or not.

  1. Eucalyptus scale bug survey at Wits campus and Tom Jenkins eucalyptus plantation in Pretoria. We would like to know if they the insects have feeding preferences between the eucalyptus species. Projects of this nature will be conducted in collaboration with Mr Nic Venter.

For more information please contact: Marcus.Byrne@wits.ac.za,
Supervisor: Dr Shalini Dukhan

Student success in the Biological Sciences

This research project is set out to assess the extent to which the marks that undergraduates perceive they will attain in their studies for Biology match the mark, which they achieve on assessments over the course of the year.  Investigations will be conducted to examine any changes to the students’ learning techniques as they progress through their studies, and reasons for drop-out. There is the possibility of an NRF grant-holder bursary for the student interested in this project.



To investigate the alignment of the marks which undergraduates expect to achieve in relation to their actual academic performance at The School of AP&ES, and to establish reasons for attrition.

To achieve the objective of the study the student will be expected to

1.       oversee the administration of a questionnaire to undergraduates at the beginning of the year and at mid-year.  The questionnaire provided at the beginning of the year is set out to gather data on the marks that participants expect to achieve in assessments at university, and to identify the study techniques which they use when they study for assessments.  The questionnaire provided at mid-year is used to identify whether the marks students expect to achieve and their study techniques have changed since the beginning of the year (both questionnaires have already been developed),

2.       conduct interviews with approximately 20 students at each level to examine their perception of the factors that influence their academic growth at university,

3.       compare the marks that undergraduates expect to achieve to their actual marks at each level,

4.       identify trends in mark expectation and any changes in study techniques as undergraduates progress through their studies.

For more information please contact: Shalini.Dukhan2@wits.ac.za, OLS 3009
Supervisor: Prof. Frances Duncan

I offer projects on insect and arthropod physiology. The following are suggestions, but interested students are welcome to discuss other ideas.

Projects on offer:

  1. Respiratory physiology of adult Anopheles mosquitoes (in collaboration with NICD). There are several aspects of respiratory physiology of mosquitoes, which need to be investigated. For example; are there different breathing patterns between the species, and changes that result from taking a blood meal? The mosquitoes will come from breeding stocks at National Institute of Communicable Diseases (NICD).

  2. How does temperature affect the metabolism, and thus growth and development, in the aquatic stages of mosquitoes? This project will measure the metabolic rates of larvae and pupa which are available from NICD.

  3. Tick physiology: Use of flow through respirometry to look at gas exchange patterns in soft ticks (tampans). Another aspect to this research would be a project investigating the spiracle structure of different species using the electron microscope.

  4. Respiratory patterns in various insects (the species to be determined).

For more information please contact: Frances.Duncan@wits.ac.za, Biology Building, B114E
Supervisor: Dr Jolene Fisher

My field of interest is spatial ecology, remote sensing and human-environment interactions. If you have an interest in these fields please come chat and I will be willing to develop a project with you. I have a research programme in KwaZulu-Natal investigating the impacts of natural resource use on forest pockets and ecosystem services. I generally offer desktop based projects using remote sensing and GIS, but occasionally have field opportunities. For more information please contact: Jolene.Fisher@wits.ac.za, Biology Building, B33A

Supervisor: Dr David Furniss

Honours projects available:

  1. Patterns of mortality in a phytoremediation project.

  2. Plant water use in Searsia lancea.

  3. Relating Landsat 8 thermal imagery to land cover and soil moisture.

  4. Any other viable project topics

For more information please contact: david.furniss@wits.ac.za

Supervisor: Dr Kelsey Glennon

My fields of interest include evolutionary biology, molecular ecology, and conservation genetics. My lab focuses on the environmental and genetic implications of flower colour variation in the plant genus Rhodohypoxis. If you are interested in taking on a project that fits into one of these fields, please come and chat to me about project ideas you might like to pursue. For more information please contact: kelsey.glennon@wits.ac.za

Supervisor: Prof. Glynis Goodman-Cron

My interests lie in systematics (patterns of relationships and classification), biogeography, speciation and pollination (reproductive) biology. I am willing to discuss and develop projects that fall within these fields.

  1. Drivers of speciation in the Drakensberg Alpine Centre

The Drakensberg Alpine Centre is a biodiversity hotspot, but relatively little is known about the drivers of speciation in the region. I have a number of projects currently underway looking at some of the endemic and near-endemic genera of the region. At Honours level, this involves morphological and molecular phylogenetic analyses, and morphometrics linked to investigating the potential roles of abiotic and biotic factors in promoting or driving speciation in a specific plant genus.

  1. Pollination studies

Pollination biology of selected plant groups to provide information relevant to their conservation. Possible projects include:

-Alpine plant species are very often able to self-pollinate due to the limited number of pollinators at high altitudes An investigation into the ability of Cineraria erodioides (Asteraceae) to self-pollinate and whether or not it is self-compatible is on offer. It would involve greenhouse-based trials and field work.

-Comparison of rayed versus rayless species of daisy (e.g. Senecio) at high altitude in the DAC.

-Comparison of the pollination biology (visitation rates, self-pollination, seed set) of a rare versus a common species in a genus.

-Why so many more insect visitors (potential pollinators) on Senecio compared to Cineraria species in the Sani Pass region? This would look at scent and other cues attracting insects to the two species.

  1. Systematic study of a plant group

Taxonomic issues around species: either investigating a group of closely related/cryptic species and/or the taxonomy of a small genus. The study would involve some field work, morphological studies of herbarium collections and possibly DNA analyses (if time and interest allow). Phylogenetic and/or phenetic analysis of morphological data and possibly some molecular data will be required.

Examples of projects on genera/species:

  1. Are Senecio seminiveus, S. tanacetopsis and S. achilleifolius (Senecioneae, Asteraceae) different species or merely altitudinal variants of the same species?

  2. Is Strelitzia juncea a distinct species from Strelitzia reginae, or should it be a subspecies or variety of S. reginae?

  3. Parasitism of an Aloe species by a wasp.

A study (in 2017) at the Skuilkranskopje Nature Reserve, Pretoria East, revealed that at least seven parasitic/parasitoid wasps and some flies are found within the seeds and fruit of Aloe pretoriensis, severely impacting the reproductive output of this species. An interesting follow–on study is needed to see if the same species of wasps and flies parasitise the species in a more rural setting, such as the Magaliesberg, and whether at the same level of parasitism.

For more information please contact: Glynis.Goodman@wits.ac.za, OLS LG 33
Supervisor: Dr Robyn Hetem

My research interests lie within the field of conservation physiology, with a focus on the physiological and behavioural mechanisms employed by free-ranging mammals in order to cope with the extreme temperatures and habitat transformation likely to occur with global climate change. Potential honours projects for 2018 include:

1.    Are large carnivores eating the rare antelope in Bwabwata National Park, Namibia?

2.    Comparison of heat transfer through the pelts of three antelope species with differing water dependencies

Please come and chat to me should you be interested in these or other projects.

For more information please contact: Robyn.hetem@wits.ac.za Biology Building, B16
Supervisor: Dr Teresa Kearney (curator at the Ditsong National Museum of Natural History [formerly Transvaal Museum])

As a curator in the small mammal section of the museum my research is primarily assessing morphology to understand changes in relation to age and sex within small mammal species, as well as for taxonomic and systematic purposes. Many small mammal species still require detailed morphological description. Please contact me if you wish to know more, or would like to discuss potential projects. Projects of a systematic nature can be done in collaboration with Prof Glynis Goodman-Cron.

For more information please contact: kearney@ditsong.org.za, 012 000 0040

Supervisor: Prof. Jason Marshal

I work on research projects that focus on applied population ecology and factors that affect the abundance and distribution of wildlife populations.  This includes analytical methods for data collected from wildlife studies.  For students looking for honours projects, I prefer that you have some idea of the type of study that you would be interested in pursuing. If wildlife conservation and analysis of wildlife data sound appealing to you, come discuss your ideas with me.

For more information please contact: Jason.Marshal@wits.ac.za, OLS 3016
Supervisor: Dr Mapula Matimolane

My research interest is on the role of assessment and feedback in promoting sustainable student learning in Biosciences.

Possible research issues to explore include:

•       Education for sustainable development and teaching sustainability in biological sciences undergraduate curriculum

•       Effectiveness of field trips in the teaching, learning and assessment of biological sciences.
•       To what extent do our current assessment practices assess the ‘ways of thinking and practicing in biosciences”?

If you are interested in such topics and have ideas for potential projects, please come discuss them with me.

For more information please contact: Mapula.Matimolane@wits.ac.za, OLS 2003

Supervisor: Mr Donald McCallum (APES Museum)

  1. Irrigating with grey water for rooftop crops.

  2. Irrigating with grey water for rooftop indigenous garden.

  3. Improving grey water quality with a micro constructed roof-top wetland.

City roof spaces are valuable and largely unutilized spaces in Johannesburg. One use with numerous benefits is the ‘green roof’ where plants are grown. Four main benefits are energy savings resulting from the insulating effects, reduced runoff, a more pleasant environment and a way of preserving biodiversity. The last benefit could be achieved directly by recreating the local plant diversity on rooftops, or by using the space for food growing and thus reducing some land needs for this elsewhere. Retro-fitted roof gardens have very shallow soil to keep weight low, and this means that they hold a very limited amount of water. Rainfall alone may not be enough to sustain most gardens and one of the ways of reducing water demand may be to use grey water. This project will examine the possibility of utilizing grey water for growing crops and for growing indigenous plants on a green roof. Test beds will be irrigated with typical untreated grey water from hand washing at Wits, untreated grey water made up using a biodegradable environmentally safe soap.

The micro wetland and indigenous plant grey water projects would need to start from the start of the block to use the growing season. A cool season crop will make a later start possible for project 1.

For more information please contact: Donald.McCallum@wits.ac.za, OLS LG 34
Supervisors: Dr Yael Dahan Moss and Prof. Lizette Koekemoer

Honours project based at National Institute of Communicable Diseases (NICD), Sandringham, Johannesburg.

Determine the mating and reproductive success of colonized An. funestus

Anopheles funestus is a major malaria vector in Africa and given the devastating effect of malaria, it is very clear that it is necessary to control this species. The only existing An. funestus colony is in South Africa and this opens up valuable and unique opportunities to study this species biologically. It is well known that the biology of An. funestus is different from other major malaria vector species such as An. arabiensis and An. gambiae, which can easily be colonized in the laboratory (insectary) and are able to rapidly reproduce (within 7 days). However, An. funestus reproduction is known to take much longer (14 days) under laboratory conditions (L. Koekemoer, pers. comm.), but this has never been published.

Understanding the factors that influence mating and the time period required for mating will enhance our general knowledge of this species and also close the information gap that exists between this major malaria vector and other African malaria vectors.

The aim of this project is to determine the effect of age, sex ratio and space on mating success in colonized An. funestus mosquitoes. The following objectives will be investigated:

i) Time period needed for optimal mating to take place

ii) Male: female ratio, which would enhance mating success

iii) Influence on cage size on mating success

For more information please contact: Prof. Lizette L Koekemoer: lizettek@nicd.ac.za/ 011-3866484; Dr Yael Dahan: yaeld@nicd.ac.za /011-5550303
Supervisor: Dr Givemore Munhenga

Honours project based at National Institute of Communicable Diseases (NICD), Sandringham, Johannesburg.

Development, optimisation and evaluation of a novel mosquito trapping devices that targets adult Anopheles arabiensis
Background and rationale

South Africa has maintained an effective malaria control programme at national and provincial levels for several decades. However, malaria remains a major public health concern as South Africa is still prone to malaria outbreaks. The low-altitude provinces of Limpopo, Mpumalanga and Kwazulu-Natal which borders Mozambique and Zimbabwe are especially at risk and still endemic to malaria recording on average 11 000 malaria cases yearly. Transmission has recently been attributed to outdoor residual transmission maintained by Anopheles arabiensis (Dandalo et al., 2016, under review) meaning that the current vector control strategy through insecticide residual spraying (IRS) of dwellings needs to be complemented by an intervention which can target this outdoor biting population. The sterile insect technique (SIT) as an additional/ alternative vector control strategy to complement existing tools was selected and is under investigation.

Prior to a full scale SIT releases programme a number of developmental activities needs to be optimised. Since the inception of feasibility studies on the applicability of SIT as a malaria vector option a number of key aspects central to the successful implementation of an SIT programme have been under investigations (Munhenga et al., 2011; Munhenga et al., 2014; Munhenga et al., 2016). One such aspect is the development of tools for pre and post release population monitoring in the area targeted for releases. Population surveillance especially for male mosquitoes is an important component of an SIT programme as it provides baseline information on the ecology and behaviour of An. arabiensis prior releases and enables assessment of performance of released males and the impact of releases on the target population. To date a mosquito surveillance system has been set up in Mamfene, northern KwaZulu-Natal a site targeted for SIT pilot releases in South Africa. The surveillance consists of mosquito sampling using two passive trapping techniques: traditional ceramic pots and modified plastic buckets placed outside households proximal to mosquito breeding sites (Dandalo, unpublished data). These low cost novel collection methods are proving to be very effective in collecting outdoor and indoor as well as male and female mosquitoes compared to traditional methods which were being used by the National Malaria Control Programme (Burke et al., 2016, under review). Despite their comparative effectiveness in collecting mosquitoes these new trapping methods are not fully addressing the surveillance requirements for an SIT programme and are facing a number of operational challenges. For example, the traps need to be cleared daily early in the morning before mosquitoes fly off to seek alternative cooler resting surfaces. This puts the safety of field teams at risk as they need to wake up very early in the morning before mosquitoes fly off. In addition, the fact that mosquitoes are not trapped inside the pots compromises the productivity of mosquito catches as not every mosquito which flies into the trap is captured as some may fly off before the collection teams arrive. Added to this, the current bulkiness of the ceramic pots makes them difficult to use under field setting. Size and weight of a trap determines whether a trap can be used practically under operational conditions. In view of this and lack of any known reliable traps that can collect both male and female Anopheles, this study intend to optimise the use of traditional ceramic pots and modified plastic buckets as a mosquito sampling tool as they have shown their potential in sampling both indoor and outdoor resting seeking Anophelines.
Aims and objectives

The aim of the project is to develop and optimize mosquito sampling tools which can be used for an active mosquito SIT surveillance system to improve the current SIT surveillance system and to strengthen the national mosquito vector monitoring procedure. This will be achieved by addressing the following specific objectives:

1) Investigate the potential of modifying ceramic pots and plastic buckets by treating their inner surfaces with either a sticky adhesive or insecticide as a ‘trap and kill’ strategy.

2) Determine the effect of using sticky surface on downstream processing of mosquito specimens

3) Investigate optimal sizes of ceramic pots which can collect adult male An. arabiensis.

4) Investigate the use of SUNA traps as possible Anopheline collection method

For more information please contact: Dr Givemore Munhenga: Givemore.Munhenga@wits.ac.za / 011-8855413

Supervisor: Prof. David Mycock

Present research interests have relevance to plant genetic resource conservation in the broadest sense. The aims and objectives of the research are directed at the development and scientific understanding of in vitro storage methods for plants that are presently difficult to store by conventional methods (e.g., vegetatively propagated crops and species that produce recalcitrant seeds). The research is also pertinent to the biotechnologically based industries, for instance in the storage of axillary buds and somatic embryos until required for regeneration and propagation. Projects are therefore offered in the following areas:

1. Development of in vitro micropropagatory techniques for selected crop and indigenous species. Species currently under investigation include Persea americana (avocado), Eucalyptus grandis, Protea spp. and Tamarix usneoides.

2. Development of storage techniques for in vitro tissues of selected crop and indigenous species e.g. endangered Protea spp. (a project conducted with Professor E. Witkowski). Both medium-term (slow growth) and long-term (cryopreservation) storage techniques are being considered.

To achieve these goals, it is essential to have a thorough scientific understanding of the underlying biological processes. Thus all the projects include in vitro technology (plant tissue culture) but can include the use of other techniques such a biochemical and ultrastructural investigations. Rather than describing individual projects here I prefer to discuss them with people on a personal basis.

For more information please contact: David.Mycock@wits.ac.za, Biology Building B138

Supervisor: Dr. Deran Reddy (Microscopy and Microanalysis Unit)

My interest lies in the architecture of the pulmonary system of the Nile crocodile. The respiratory tract of the Nile crocodile is not very well / not documented at all. Documenting the structural parameters that comprise this pulmonary system are not only important in understanding how the organisms breathe but also the evolution of vertebrate respiration. The project(s) that are on offer will examine the form of various aspects of the respiratory tract to infer function. If you have any questions or are interested in such a project, please come and chat to me.

For more information please contact: Deran.Reddy@wits.ac.za, 011 717 1336

Room: OLS 1009 or Biology building B2A.

Supervisor: Prof. Bob Scholes, GCSRI

I am willing to work with one or two numerate and self-motivated honours students to design and implement a project of their choice, in the area of ecosystem function. Here are some examples:

1. Water limitation at landscape scale. Prediction of Gross Primary Production at regional scales from satellite-measured FAPAR assumes that when the leaves are present, they are photosynthesizing. In reality, for a large part of that time the leaves are present, but the stomata are closed. What is needed is a modifier term f(H2O) which ranges from 0 to 1, to reduce production during times of water stress but before leaves are lost. Use the long-term flux records of water and carbon dioxide from the Skukuza flux site to develop a simple predictive model of stomatal closure in relation to soil moisture.

2. The relationship between stomatal conductance and xylem potential in savanna trees. Water loss by plants is controlled by their stomata. The current models used to predict stomatal closure from measures of plant water stress (VPD, PAR, xylem) don’t work very well for plants from arid and semi-arid ecosystems such as savannas. Measure the relationship between stomatal conductance and xylem pressure potential for a savanna tree species (Colophospermum mopane) and fit a simple predictive model to it.

3. Functional traits for a spectrum of savanna leaf types. There are fundamental tradeoffs in leaf ecophysiology between leaf dimensions, specific leaf area, stomatal conductance, leaf nitrogen and leaf assimilation rate. From a selection of tree leaves showing different life histories (evergreen, facultatively deciduous, obligate deciduous, ‘water user’vs ‘water saver’, succulent vs non succulent, nano-, micro and mesophyll, etc.), measure the leaf dimensions, leaf area, specific leaf area, N content, stomatal density and pore size, point of turgor loss, fully hydrated water content, maximum stomatal conductivity and leaf chlorophyll content. Perform a multivariate analysis to see if these traits assort into functional types or form a predictable continuum.

4. The environmental history of a fenceline contrast. Sharp contrasts, usually of woody cover, between adjacent farms provide a ‘natural experiment’ to help understand the causes of ecosystem change. A contrast between adjacent grassland and Leucosidea sericea thicket on the Mpumalanga escarpment is a chance to understand the triggers of state change, in a possibly bi-stable situation representative of large parts of the montane grasslands in South Africa.

5. Wood respiration. The difference between Gross Primary Production and Net Primary Production is due to Autotrophic Respiration (Ra). While Ra for leaves can be estimated from the y-intercept of Assimilation-Irradiance curves, it has never been measured for the other main contributor in tree, the wood. Modify a respirometer soil chamber to measure stem respiration, and take a set of measurements at different temperatures through the day and night, to develop a predictive function for wood respiration in a savanna tree species.

For more information please contact: Bob.Scholes@wits.ac.za, GCSRI, 5th floor, University Corner.
Supervisor: Prof. Mary Scholes

1. Impacts of pollution on soils, plants and water in the Waterberg

2. Food security in Gauteng

For more information please contact: Mary.Scholes@wits.ac.za, Biology Building, B20
Supervisor: Prof. Stuart Sym

Several interesting new species of marine microalgae exist in my culture collection that require characterisation at the light and electron microscope level, supplemented with some limited autecological studies. Honours candidates with any interest in this or indeed other aspects of microalgae or applications thereof are encouraged to contact me.

For more information please contact: stuart.sym@wits.ac.za Biology Buiding B134
Supervisor: Prof. Wayne Twine (Wits Rural Facility)

My research focuses on resource ecology and human-environment relationships in rural communities in savannas. However, I am no longer supervising social projects at honours level, due to the challenging and time-consuming complexities of social research in local communities, including ethics clearance, community entry, permission from local authorities, community feedback etc. My honours projects on offer are thus ecological rather than social, with some focus on communal lands. Students under my supervisions do their fieldwork based at the Wits Rural Facility (WRF) on the border of Limpopo and Mpumalanga Provinces. Because I am not based on campus, my students are strongly advised to find a co-supervisor for their project for extra support.

Projects on offer:

  1. Comparing the accuracy, precision, and efficiency of two techniques for monitoring herbaceous vegetation in communal rangelands. Herbaceous vegetation is currently being monitored in permanent transects around nine rural villages in Bushbuckridge, Mpumalanga Province, as part of an on-going project (SUCSES – Sustainability in Communal Socio-Ecological Systems). The current study design uses a plotless (point) method to quantify herbaceous basal and aerial cover, and species composition. Although this method is quick and easy, there is concern that the accuracy and precision of this method is insufficient to detect real changes over time. This project will compare the current plotless method with a plot method using varying sampling intensities, to assess the trade-offs between accuracy, precision and efficiency of these methods. You will be making an important scientific contribution to a current research project.

  2. Allometric relationships between tree height, crown dimensions, and stem diameter in selected singled-stemmed versus multi-stemmed savanna trees. Establishing the quantitative relations between key characteristic dimensions of trees (allometry) is important for understanding physical constraints to growth and for predicting key ecologically important variables such as aboveground woody biomass. General allometric relationships between tree morphology and biomass have been derived for savanna trees, but these usually pool the stem diameters of multi-stemmed trees (which are common in savannas). This method assumes that the relationship between total stem diameter, tree height and canopy dimensions are the same for single stemmed and multi-stemmed savanna trees. However, this assumption has not been tested, and evidence suggests that it may not be valid. This is a potentially important source of error in generic allometric biomass calculations for savannas. Your study will shed new light on this issue with field data that you will collect at the Wits Rural Facility, making an important contribution to savanna ecology research.

  3. Population assessment of a newly discovered population of Sapium integerrimum. During fieldwork in the communal lands of Xanthia village in Bushbuckridge in January 2016, I discovered a population of a forest-fringe tree species, Sapium integerrimum. This species is endemic to the coastal region of northern KZN and very southern Mozambique, with isolated populations reported in Swaziland and in the SA lowveld south of the Kruger National Park. The population discovered in Bushbuckridge is thus well north and west of the reported distribution. You will do a population assessment of this species in the locality to determine abundance and population structure. You will also characterise the vegetation in which the population occurs. This is an exciting project, with the potential for you to publish a paper with me.

  4. Quantifying the rate of wood harvesting in a communal rangeland. Since January 2015, I have had field assistants recording any new harvesting of tree stems for fuelwood on a monthly basis in 18 large plots located in communal rangelands of Bushbuckridge. You will accompany the field assistants into the field to learn how they collect the data, and then you will analyse the two years of data collected to quantify the mean harvesting rate of wood per hectare per month. You will assess differences in harvesting rates between seasons and between different distances from villages. This study will make an important contribution to assessing the sustainability of fuelwood harvesting in rural areas.

  5. Comparing herbaceous recovery in lightly and heavily grazed areas after a drought. The 2015/2016 drought in the central lowveld was broken with good rains in December 2016 and January 2017. During the drought, the herbaceous layer on the lightly stocked Wits Rural Facility and neighbouring communal lands was reduced to similarly very low levels of cover. You will compare the recovery of the herbaceous layer in these two different landuses, in terms of species composition, and grass vs forb density and biomass.

For more information please contact: Wayne.Twine@wits.ac.za.

Supervisor: Mr Nic Venter and Dr Solomon Newete

We have the following research topics available for Honours 2018.

  1. Eucalyptus scale bug survey at Wits campus and Tom Jenkins eucalyptus plantation in Pretoria

  2. Physiology of mite induced flower galls on Lantana sp.

  3. Establishment of lantana lace bug

  4. Tamarix drought experiment

For more information please contact: Nic.Venter@wits.ac.za, OLS 1002.

Supervisor: Prof. Coleen Vogel

1. Citizen science – the role of citizen science in enhancing ecological knowledge.

2. Knowledge practices–how can we track social learning to better adapt to global and local environmental change? Possibly use the case of Delta Environmental Centre, which is involved in a green/biodiversity works programme.

3. Using a simple case study, show what or how one can use co-engaged learning in conservation management.

4. What are the impacts of drought on biodiversity? Are they robust or weak? What drives or enhances species response to extreme droughts?

5. Exploring the Science / policy/ practice interface.

For more information please contact: Coleen.Vogel@wits.ac.za, University Corner, GCSRI

Supervisors: Mr Nic Venter and Dr Danica Marlin

Our main research area is in the field of biological control of invasive plants, and this covers plant-insect interactions. All the projects below will require you to work with plants and or insects. For a general background on biological control of invasive plants, see McFadyen 1998 – Annual Review of Entomology. We welcome students who have their own ideas for projects, within the field of biological control of weeds.

1) Tamarix salt experiment: It is suspected that different Tamarix species and hybrids take up salts from soil in different quantities, and this may impact insect feeding preferences. This project will therefore look at 1) differences in the salt content of different Tamarix species grown under three different salt regimes, and 2) whether the salt content of the different Tamarix species influences the feeding preferences of Tamarix insects, either the beetles Diorhabda carinulata or the leafhopper Opsius stactogalus. Reference(s): Munns et al. 2010; Dudley et al. 2011
2) Breeding systems of Tamarix: Are Tamarix species self-compatible or not? Do they produce more seeds when cross- or self-pollinated? This project will test Baker’s law which roughly states that self-compatible individuals only need a single propagule to start a sexually-reproducing colony, which makes establishment more likely than if the chance meeting of two self-incompatible yet cross-compatible individuals, which are sufficiently close together spatially and temporally, takes place. References: Baker 1955, 1967
3) Invasiveness of Bugweed: South Africa has a number of Solanum species, some of which are indigenous e.g. S. panduriforme, and some invasive e.g. S. mauritianum. This project will examine the growth and physiology of the abovementioned Solanum species, to determine whether the invasiveness of the species is as a result of bird propagule (seed) dispersal, or rather a result of plant physiological parameters. Reference (s): Olckers and Hulley 1991
4) Development of the Parthenium beetle Zygogramma bicolorata: Parthenium hysterophorus is an invasive weed in South Africa. The leaf-feeding beetle Z. bicolorata is a successful biological control agent of the weed, but only in certain areas of the country. This project will examine the development of the beetles on Parthenium plants grown under different nutrient regimes. Reference(s): Strathie et al. 2011
For more information please contact: Danica.Marlin@wits.ac.za, OLS 1008 and Nic.Venter@wits.ac.za, OLS 1002
Yüklə 68,91 Kb.

Dostları ilə paylaş:

Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©muhaz.org 2024
rəhbərliyinə müraciət

gir | qeydiyyatdan keç
    Ana səhifə