Research Proposal Poster Session and Afternoon Tea

Rangelands play a vital role and contribute significantly to the livelihoods and well-being of South Africans. They are the main source of forage for livestock which are considered as wealth (economical, cultural and spiritual) and they support livelihoods through the provision of several goods and services. Communal livestock is currently managed under a continuous grazing system where livestock free range with absence of herding. The aim of this study is to assess the effect of livestock grazing patterns on plant species composition in communal rangelands of Cata and Guquka. The emergence of Geographical Positioning Systems (GPS) technology has resulted in significantly easy and flexible techniques of studying livestock behaviour and movement. Therefore GPS collars will be used to determine the livestock grazing pattern of 12 cattle (six in each study site). The GPS collars will be fitted on livestock to record their position at 15 minute intervals for four weeks in the dry and wet season. The data will be downloaded using CatLog Generation 2 and R Studio i386 3.1.1(statistic package). Data will then be imported into ArcGIS 10.1, to create density maps showing areas that are frequently grazed. Then species composition of these frequently grazed areas will be determined through a point to tuft distance method. The expected outcome is that the frequently grazed areas will have mostly decreaser grass species which shows the palatability and health of the rangelands such as Digitaria Eriantha and Themeda Triandra. When overgrazed these grass species stand the risk of being replaced by increasers grass species. 

Effective body condition scores have been developed for other wildlife species, such as: elephant (Fernando et al., 2009), black rhino (Reuter & Adcock, 1998) and arabian oryx (Alqamy, 2013). The main aim of this study will be to better understand giraffes’ overall performance and condition and how to manage that better before the loss of physical condition. This will allow the recognition of BCS changes in time, in a non-invasive manner. Trying to apply this on giraffe in extensive systems will be novel, and monitoring the different factors will help to understand and manage giraffe better. Variable factors such as habitat loss and fragmentations are known to be some of the biggest causes for animals to lose physical body condition. This study will investigate links between the habitat and animal health in extensive systems by developing a BCS through visual examination and by inspecting possible factors that can lead to or indicate a change in the BCS. This monitoring will include the inspection of endo-parasite infestation, tree biomass and nutrient quality of the food that giraffe consume. Included for the study are giraffe populations existing on five different reserves, wheregiraffe within the Free State are considered as an extralimital herbivore. Part of the investigation will also include bacterial and virological monitoring and will be analysed at the microbiology department. The 5 reserves differ greatly in terms of management practices, which we expect to be adding to the factors. Fecal samples will be analysed by the state veterinarian for each of the specified individuals using the MacMaster method (MAFF, 1986). Plant samples will be analysed for nutrient quality and to determine nutritional deficiencies (Janecke & Smit, 2011). The biomass and dry matter will also be determined, as well as which species are favoured and utilised, using the BECVOL-model (Smit, 1989). A full genome virus detection using sensitive nucleic acid preparation will be used to identify any viruses present (Cotten, et al., 2014). The BCS system and criteria was set up by Kearney & Ball in 2001 on giraffe that lived in captivity and zoo-systems. Hypothesizing that fluctuations in the parasite-load will possibly be linked to a reason/s, such as feeding habits and management practices leading to a change in physical condition. With giraffe resources and biodiversity rapidly shrinking in Africa, we need to understand conservation and resource management within different environments better, in order toimprove our management decisions. If physical conditions of giraffe can be evaluated objectively, it can be used to manage the giraffe and their remaining resources more effectively.

The South African giraffe, Giraffa camelopardalis giraffa, together with the Angolan giraffe, Giraffa camelopardalis angolensis, populations coexist in South Africa after being reintroduced into areas where they historically occurred and did not occur (extralimital). However, many of these subpopulations were and are being translocated into areas without real knowledge on their taxonomic status, adaptation success or habitat suitability, as well as taking into consideration the possibility of inbreeding. The aim of this study is to fill this gap by determining the status and developing of a conservation plan for the South African giraffe subpopulations in South Africa in terms of creating a habitat suitability index to improve the success rate of these translocations in the future. As what the aim was with other wildlife species such as the white rhino, Ceratotherium simum, (Knight, et al., 2015) and the cheetah, Acinonyx jubatus, (Lindsey & Davies-Mostert, 2009), etc. In general this plan will help firstly to understand but also then to develop a status distribution and habitat suitability map of giraffe in the different biomes of South Africa, including past and present translocation successes. Firstly, this study serves to develop a baseline/guideline for the development of a habitat scoring system to assist farmers in determining giraffe habitat suitability before giraffes are translocated. Secondly, it serves to create a baseline/guideline for future genetic studies to determine the genetic integrity of the subpopulation and to avoid inbreeding or the unnecessary loss of animals. In addition, this study will help to improve future decisions and translocations. Historical translocation data within each province and between provinces, nature reserves and private stakeholders owning giraffe will help to determine the outcome. From the datasets a detailed analyses will be done on how many individuals were translocated, the success of these translocations and how the translocations were in combination with preferred habitat types. The index will make use of historical distributions and more recent as well as current data on giraffe in the country with suitable habitat perimeters. This in turn will help to provide outcomes for management and future decision making to keep a healthy and divers genetic giraffe population in SA. This will be done primarily by obtaining all current information on the presence/absence of giraffes for specific habitat types, their actual numbers and translocation details from all national and provincial nature conservation agencies, in order to establish as well as evaluate the current available data on giraffe in South Africa. Thereafter, specific organisations will be contacted to distribute data mining surveys to individual game ranching members, along with direct interviews/phone calls with individual game ranchers.
 

In South Africa, it is estimated that approximately 16.9 million hectares of land is suitable for the establishment of forage legumes. In the Western Cape, approximately 2.5 million hectares of land is currently being cultivated, of which an estimated 600 000 hectares is planted with legumes. The most important annual pasture legumes cultivated in the Western Cape are annual Medicago (M. polymorpha, M. truncatula) and Trifolium (T. subterraneum, T. michelianum) species. Because these Medic and Clover species used in South African pasture-crop rotations are not native to South Africa, they first need to be tested for their ability to adapt to specific agro-ecological, bioclimatic and edaphic conditions. The current stock of commercially available forage legumes are well adapted to the current bioclimatic conditions of South Africa. However, climatic predictions for the Western Cape are indicating a trend of becoming hotter and drier. Unfortunately, no information is currently available in South Africa to predict the responses of commercially available Medics and Clovers to future changes in bioclimatic conditions. These future changes in the bioclimatic conditions of South Africa, specifically the amount and distribution of rainfall and rising temperatures within the Western Cape, could significantly affect the success of these legume-based pastures, affecting the establishment of these species/cultivars and their persistence.  It is therefore important to obtain a greater understanding of how currently commercially available cultivars of annual forage legumes will respond to the predicted bioclimatic changes, especially changes in moisture availability and rising temperatures during germination and establishment of the forages. This in turn, could play a major role in the establishment of these forages under the predicted marginal conditions within the Western Cape. The aims of the current study are therefore: 1) to quantify the germination responses of Medics and Clovers to temperature and water stress; 2) to quantify seedling establishment, growth, and development under different levels of water-limitation, and; 3) to quantify the ability of Medics and Clovers to recover after different levels of water-limitation. 

Bush-thickening resulting in decreased agricultural productivity, inaccessible thickets and increased occurrence of pseudo-droughts is a common phenomenon in the semi-arid southern African savanna. Until recently, land users paid little attention to Tarchonanthus camphoratus, but there is a growing awareness of the potential threat that this species presents, largely because it:  (1) reproduces sexual (seeds) and asexual (root suckers), (2) is evergreen, thus requires water all year round, (3) is not readily browsed by domestic livestock or game, and (4) is fire tolerant. To ensure effective management of T. camphoratus this research is aimed to obtain a better understanding of the ecology of this species. The research will be conducted in the Rooipoort Nature Reserve west of Kimberley in the Northern Cape Province on deep well-drained sandy soil and on shallow rocky soil.  The proposed methods include:  (1) a study of the phenology of marked trees by allocating a monthly leaf carriage score with classification of leaves into different phenophases and noting the presence of flowers and fruits, (2) monthly measurements of shoot lengths and base diameters to measure growth rates, (3) assessment of the coppicing ability of cut plants that were felled in summer and winter to compare the effect of season of cutting on regrowth, (4) determination of the existence of a soil seed bank and performing germination tests on these seeds , (5) collecting soil from three different subhabitats (at the stem and in the canopied and uncanopied zone) for chemical analyses to assess soil enrichment, (6) investigation of possible allopathic effects by growing seedlings in soil from these subhabitats under controlled conditions in a greenhouse, (7) quantify root biomass and depth distribution by excavating monoliths of soil and washing the soil from the roots and, (8) investigate the response to fire of T. camphoratus and a co-dominant species, Senegalia mellifera.  In addition, regression equations relating spatial canopy volume to leaf and wood biomass according to the BECVOL-3 (Biomass Estimates from Canopy Volume) model will be developed from harvested undamaged and coppicing plants in accordance with Smit (2014).



 

Giraffe (Giraffa camelopardalis) are currently listed as s ‘vulnerable’ on the IUCN red list as populations have declined by almost 40% and have become extinct in seven African countries over the last three decades; hence, the increasing need to move groups of individuals for conservation and management purposes. Despite this, literature on the translocation of giraffes is lacking, and could be ascribed to the high risk activity thereof both, humans and giraffes. It is known for many species that translocations are stressful events, which can lead to mortalities. Long-term stress can have a negative effect on the immune and reproductive function as well as disease resistance of an individual. The aim of this study is to identify the least stressful translocation method for giraffe. To deal with stressful situations, glucocorticoids are secreted by the adrenal glands. Modern techniques allow that metabolites can be measured in the faeces of animals, also called faecal glucocorticoid metabolism (fGCM). This research focusses on different methods of translocations and their effects on the fGCM levels of the giraffes. Translocations throughout South Africa will be monitored from one game farm/reserve to another. Pre and post faecal samples will be collected at both sides (primary and secondary locations). In some cases the animal will first be moved to a boma before release into their new environment, samples will also be collected during that period. Samples will be preserved on ice in the field and stored in a freezer until it will be analysed using the 3α ,11-oxo– CM enzyme immuno-assay. A pilot study in 2017 has been done on six sub-adults (three males and three females). The giraffes were translocated from one game reserve (36,000 ha) to another (3,500 ha), both situated in the Northern Cape, South Africa. The farms are approximately 130 km apart with similar climate and vegetation. The giraffes were released directly into their new environment. As the glucocorticoid metabolites have a delay of 1.6 days, pre-samples were taken from the rectum at the day of translocation. Only during the second week after the translocation, the giraffes allowed researchers to get close (approximately 150 m) to collect samples, suggesting that they already started to feel less stressed than the first week (where sample collection was impossible). Only one sample at day 6 after translocating showed significantly elevated fGCM levels (5.86 times higher) compared with the pre-samples taken from the rectum. Nonetheless after two weeks the fGCM levels seem still to be slightly higher (ranging from 1.96-4.85, µ3.56) as prior translocation (ranging from 1.00-2.89, µ1.96).

 
Seriphium plumosum is an indigenous, woody, perennial shrub-let, with greyish, slender and wiry branches. S.plumosum encroachment decreases the grazing capacity of grassland by approximately 80%. Due to this encroachment threat in South African grassland, most farmers tend to lose about 100% of their natural veld. Despite the fact that it is detrimental to grazing capacity, which subsequently affect livestock productivity, this plant, is useful in other aspects. S.plumosum yield volatile oil and provide long lasting foliage. However, its use as ruminant supplement is unknown. This study seeks to evaluate the use of S. plumosum and natural pasture-based feed ingredients (maize, silage & peanut hay) as supplements on Free Range Beef for improvement of growth rate, carcass & meat quality. The objectives are 1) to formulate diet for supplement in Free Range Beef using S. plumosum 2) to compare growth performance, meat sensory and nutritional quality of Free Range Beef fed S. plumosum and natural pasture-based feed ingredients. Three on-farm trials will be conducted in three provinces i.e. Limpopo, Mpumalanga & Gauteng provinces. The study will be designed as completely randomised with a 2 x 4 factorial arrangement of treatments (1 control, 1 natural pasture grazing, 1 maize, 1 maize + silage, 1 maize + peanut hay ). Forty ± 30 months old mixed breed will be divided into four groups of 10 steers per group.Growth performance will be measured fortnightly throughout the 90 days experimental period. Difference in weight gain will be determined by weighing animals at the beginning of experiment then minus weight gained within every 14 days. Nutritional composition of the feed ingredients and test diets will be evaluated at ARC Nutrition Labs. Twenty-four hours prior to slaughter, animals will be weighed and transported to Cavallier abattoir. At the abattoir, the animals will be slaughtered and dressed following the standard commercial procedures. Data will be analysed using the PROC MIXED procedure of SAS (2009).

Medicago sativa (Lucerne) is a perennial legume species that is cultivated worldwide. It is arguably the most widely used pasture and hay crop in South Africa due to its high palatability and high forage quality. Only Lucerne cultivars that are registered on the South African variety list may be sold in South Africa. There are approximately 46 different cultivars on this list that are bred for specific agro ecological conditions. The number of cultivars on this list, however, regularly changes. These cultivars are then further divided, based on the degree to which they are dormant during the winter. Winter dormancy, based on the American ranking system, ranges from 1 which is highly dormant during winter, and 11 which is highly winter active. Due to the large number of Lucerne varieties available and the corresponding large variation in winter dormancy, it is often challenging for livestock and hay producers to select a variety that is best suited to their specific agro-ecological requirements. This is because dormancy class not only affects the seasonal distribution of production in Lucerne, but is often associated with the ability of the variety to handle environmental stressors such as cold and drought, and its tolerance to grazing. In turn, varieties within a dormancy class often show large variation in terms of production potential, persistence and resistance to pests and diseases. Therefore, it is important to know the production potential of cultivars under particular bioclimatic and edaphic conditions. We therefore propose the need to urgently evaluate the production of all available Lucerne cultivars under the same agro-ecological conditions in the Pretoria area, where bioclimatic conditions are classified as moderately dry sub-tropical in nature, with long hot and rainy summers and cool, short and dry winters.

Using vegetation as a primary indicator of the state of rangeland health is based on the assumption that vegetation is a reliable mirror of its ecological environment. Over the years this assumption has led to the development of many rangeland condition scoring methods, however vegetation is not the only aspect of an ecosystem. Investigating literature, it was found that rangeland soils and their associated properties are one of the least studied aspects of rangeland ecology, especially research which connects the above-ground condition of rangelands and the below ground condition of soils. Soil, animal and plant health each affect the overall condition of a rangeland, measuring these three aspects together, in order to objectively score the veld, is severely complex. It has been well documented that there is a reciprocal relationship between herbivores and the condition and composition of the plants they utilize. This study will broaden the traditional view of veld condition scoring to incorporate soil condition and aim to develop a plant based method using correlations. This will be achieved by assessing the condition of the veld whereby it incorporates the soil condition based on soil quality indicators. The soil condition could then correlate with the ecological and/or agricultural plant status. Providing them both an ecological resilience score and an agricultural score at the same time. Soil benchmarks may also be calculated and scored based on known soil quality indicators. To be as objective as possible, ten individuals of four herbivores species will be collared using GPS collars in the Northern Cape. The data will be expressed as heat maps of preferred and avoided areas. On these preferred and avoided areas both vegetation samples and soil samples will be taken for analysis, and a variety of both ecological and agricultural vegetation surveys will be done. Both the soil benchmarks and the ecological resilience score are novel ideas and will aid rangeland scientists in the future.

Lucerne (Medicago sativa) forms part of long-rotation cropping systems integrated with livestock in the southern Cape of South Africa. The region has a predominantly winter-rainfall pattern resulting in low productivity during cold winters and dry summers. Integration of livestock in cropping systems may improve resource utilisation. The aim of this study is to determine whether it is viable to establish a high quality forage for cropping systems integrated with livestock through oversowing dryland lucerne. For the pasture to be considered viable, the soil quality must be maintained or improved, productivity of the lucerne phase must be enhanced and the forage must be of a high enough quality to increase the number of animals it can sustain when compared to a pure lucerne sward. Field experiments will be conducted at Tygerhoek Research Farm (Riversonderend) during the 2018 and 2019 growing seasons. The experiment will be laid out in a split-plot design with four replicates. Whole plots will consist of 12 species compositions and sub-plots will have two levels of crop residue (high or low) in which lucerne was sward was established in 2017.Each sub-plot will cover an area of 2.5 x 24 m. Species composition treatments involve oversowing either single species or mixes of species into a lucerne base that was established in April 2017. Single species treatments will include oats, forage barley, stooling rye, westerwolds ryegrass, forage radish and canola. Mixes will consist of various combinations of hybrid ryegrass, Italian ryegrass, forage barley, oats, various annual Medicago and clover species, vetch and forage radish. Herbage production and agro-ecosystem benefits will be assessed according to soil, plant and herbage quality measurements. Representative soil samples will be taken annually for the duration of the study at depths of 0-15 cm and 15-30 cm. Standard soil fertility tests will be performed to evaluate if there was any improvement in soil fertility. Additional soil test indicators will include organic C, total N, C:N, active C, microbial biomass C, potentially mineralisable N, soil enzyme activity, nematode population composition and aggregate stability. Lucerne longevity, herbage production, herbage removal during grazing and both pre- and post-grazing species composition will be measured to determine the best oversown treatment. Herbage quality will be assessed through analyses for dry matter, ash, crude protein, fat, crude fibre, acid detergent fibre, neutral detergent fibre and total digestible nutrients will be calculated. The identification of a more productive lucerne phase may increase overall productivity of farmers in the southern Cape. Possible spin-offs of livestock integration may include diversified income through wool and meat production, as well as weed suppression, environmental stability, reduced nutrient leaching and improved resource utilisation. Further research is required to realise the full potential and effect of an improved lucerne phase.



   

The diversity-stability debate is among the longest running ecological debates. For decades empirical studies have been carried out, however, many of these have only considered a limited number of diversity and stability indices. This has restricted our understanding of the specific mechanisms driving stability. Recent reviews have consistently called for more experimental research measuring diversity and stability beyond only grass species and biomass production whilst suggesting that the inter-trophic level complexity is likely an important driver. If this idea is true, then understanding each trophic level’s importance and contribution towards ecosystem stability is key to advancing both empirical and applied ecology which could aid ecosystem conservation efforts. This project aims to contribute importantly to the debate by expanding our understanding of these mechanisms. Firstly, a systematic map of the current status of the diversity-stability debate within the grassland ecosystem will be carried out to quantitatively identify knowledge gaps and knowledge clusters for future systematic reviewing and meta-analyses. Secondly, field experiments where four trophic levels (insects, grasses, forbs, belowground microbes) will be removed from grassland plots will be initiated. The resulting effect on grassland ecosystem stability (measured from both biotic and abiotic ecosystem components) will then be quantified and the results discussed.

Remote sensing can be used to detect vegetation condition and soil degradation caused by among other factors, woody plant encroachment. In South Africa, Seriphium plumosum encroachment threatens the sustainability of grasslands because it reduces grass species composition, diversity and increases the runoff of water and nutrients. However, its causes on rangelands communities remain little understood, yet important in managing its encroachment, particularly in the semi-arid grassland communities. Although local factors such as fire suppression, herbivory, soil texture and fertility are proposed to interact to cause woody plant encroachment worldwide, these factors are however, not adequately explored as causes of S. plumosum encroachment. To this end, the study seek to explore the use of remote sensing to explore role of soil texture in facilitating S. plumosum encroachment susceptibility in South African grassland communities. We hypothesis that, an increase in course soil texture will increase S. plumosum density because of the separation in rooting depth between herbaceous and woody or shrubby plants, which allow woody or shrubby plant to use mainly water in deep soil profile. Data on soil texture (Sand (%) and silt (silt (%)) will be derived using ArcGIS (Version 10.5) software. Data on S. plumosum density was obtained in the field by counting in a 2 m x 50 m plots from 34 S. plumosum encroached livestock farms in Gauteng province. Since the assumption is that soil texture will influence S.plumosum encroachment susceptibility, a regression analysis will be used to correlation soil texture (sand (%), silt (%)) and S. plumosum density. The result obtained in this work will contribute insight necessary to understand the relationship of S. plumosum with soil texture in South African grassland communities. Consequently, this information will contribute to managing and controlling S. plumosum encroachment of rangelands.
 

The control of encroaching woody plants is a tremendous problem worldwide since control methods are frequently not economically justifiable. Information gathered about the effects of bush clearing in grazing areas of South African savannah biomes may have not necessarily been aimed at relating the consequences to monetary gain or loss. However, it is evident that there has been ecological benefit in the use of arboricides in controlling woody plants. The fact of the matter is farmers are interested in striking the balance between money spend on control operation and veld improvement realised. It is therefore necessary to evaluate commonly used bush control arboricide in order to ascertain its effectiveness and practicality to small-scale and commercial farmers. The aim of the project is to evaluate the financial viability, implications and ecological gain of bush clearing.To achieve this, the efficiency and effectiveness of different application rates of Tebuthiuron granules on the control of indigenous woody plants will be evaluated and monitored on Melton LIC in the Dr Ruth Segomotsi Mompati district of the North West province. Tebuthiuron is a soil applied arboricide with long residual action for the control of woody plants in natural grazing. For the treatments a number of trees/shrub species will be identified for elimination/thinning at the time of trial establishment relying solely on the use of an arboricide Tebuthiuron. The identified trees/shrubs will be given appropriate dosage of this arboricide and their canopies left intact. The arboricide will be applied in the soil around the base of the target plant. The study site is comprised of 15 plots of one hectare each in a randomized block design.Within each plot, the woody plants will be thinned to represent the different treatments, according to bush density and application rate, ranging from 50 % below-, 25 % below-, 0 %, recommended and 25 % above recommended dosage treatments. After the treatment has been applied, the effectiveness will be monitored over a period of time and different surveys will be carried out to collect different data aspects. Annual grass surveys will include herbaceous production, species composition, herbaceous (quality) analysis as well as soil seed bank studies. Every third year a more comprehensive grass basal cover survey will take place. Woody plants surveys will include bush density and dry matter production, carried out on a biennial basis. Soil samples and rainfall will be monitored. Multivariate Data Analyses will determine changes in tree species composition, biomass production and general phonological characteristics, and collectively used to evaluate different treatments for tree growth and mortality over time. Correlations between species occurrence, environmental and soil factors will also be carried out. The statistical programs Genstat (Payne, 2014) or Statistica will be used to carry out analysis of variance (ANOVA’s). Treatment means will be separated using Fisher’s protected t-test least significant difference (LSD) at the 5 % level of significance (Statistica for Windows, 1995). Costing will be done regarding labour and arboricide with regards to effectiveness and application times, to ascertain its effectiveness and practicality to small-scale and commercial farmers.

In South Africa, the problem of invasive species encroachment has been a concern for many years and it is anticipated to intensify. Seriphium plumosum is an indigenous shrub species of Asteraceae family that has converted most rangelands in grassland biome into less productive shrub land, particularly in the Eastern Cape, Free State, Mpumalanga, North West and Gauteng provinces. This shrub outcompetes the resident grass species and endangers valuable grasslands which are the main source and cheapest forage available for livestock and wildlife. Thus, there has been a great reduction in grazing capacity and stocking rate on rangelands, which has affected the livestock production for both subsistence and commercial farmers. Although, Seriphium plumosum occurrence is attributed to the interaction of different factors such as continuous anthropogenic-related disturbance, heavy grazing, fire regime, climate change, management regime and animal seed dispersal, it is still highly complex, debatable and controversial at times. There is very limited scientific knowledge about the plant’s preferred habitat and very little has been published on species distribution patterns and extent of encroachment. Thus, effective control strategies will require accurate detection, spatial distribution patterns and to quantify the extent of encroachment. Traditionally, identification, monitoring and mapping of invasive species were done through field survey which is still useful and provides details information. However, there are rarely feasible, costly, time-consuming, and inefficient for larger scale areas and in inaccessible terrain. Remote sensing technology offers economical, efficiency and practicality methodology to identify or discriminate and quantity invasive species. The project aim to use Sentinel-2 with improved finer resolution (10m) to identify and quantify the spatial distribution of Seriphium plumosum using Sentinel 2 imagery and Random Forest and Support Vector Machine Classifiers. Red Edge with 3 bands, gives sensor the ability to detect biophysical and biochemical properties of target species. Thus, sensor’s red edge enable it to discriminate between plant species. Objectives are to (1) Identify a robust and reliable method for discriminating Seriphium plumosum from native grass species communities, (2) To test the applicability of Object based Image Analysis (OBIA) on Sentinel-2 bands combined with environmental variables such as species phenology and texture using machine learning techniques such as RF and SVM and (3) Compare the mapping capabilities of the Pixel based and Object based Image analysis using machine. learning algorithm such as Support Vector Machine (SVM) and Random Forest (RF) as classifiers.