A5079743700- Ecology and Vegetation Dynamics Studies
- Plant and animal studies
- Wildlife Ecology and Conservation
- Plant Parasitism and Resistance
- Ruminant Nutrition and Digestive Physiology
- African Botany and Ecology Studies
- Rangeland Management and Livestock Ecology
- Animal Ecology and Behavior Studies
- Plant Water Relations and Carbon Dynamics
- Forest Insect Ecology and Management
- Botany and Plant Ecology Studies
- Entomological Studies and Ecology
- Soil Carbon and Nitrogen Dynamics
- Genetic and phenotypic traits in livestock
- Fire effects on ecosystems
- Plant Diversity and Evolution
- Atmospheric chemistry and aerosols
- Fermentation and Sensory Analysis
- Pasture and Agricultural Systems
- Plant Ecology and Soil Science
- Advanced Chemical Sensor Technologies
- Rangeland and Wildlife Management
- Food composition and properties
- Global Trade and Competitiveness
- Seed and Plant Biochemistry
University of Cape Town
2015-2024
University of the Western Cape
2005-2012
University of Eastern Finland
2012
Animal Production Institute
2012
Abstract Recent work suggests that savanna woody plant species utilise two different strategies based on their defences against herbivory; a low nutrient/high chemical defence strategy and nutrition paired with mostly architectural strategy. The concept structural can augment each other do not necessarily trade‐off has emanated from this work. In study, we examine strategies, how these respond to herbivore removal they affect growth in an East African savanna. At three long‐term exclosure...
Abstract: Plant responses to herbivory vary depending on type, yet the comparative effects of defoliation (e.g. by insects) and pruning large mammals) a single tree species are poorly documented. We investigated this in Northern Province South Africa comparing regrowth Colophospermum mopane trees previously defoliated caterpillars or pruned elephants, two main browsers C. foliage. Shoots were up 160% 125% longer after natural (elephant) simulated leaves ~25% (n = 13–15 per treatment). Shoot...
Access to good-quality forages is one of the major limitations livestock production in semi-arid pastoral systems. This study aimed determine whether there are differences nutritional quality diets selected by herded and free-ranging goat sheep flocks utilising Namaqualand Granite Renosterveld vegetation during wet dry seasons. Plant samples collected along grazing routes were dried analysed for their fibre, condensed tannin, total phenolic mineral nutrient contents. The showed that a large...
The shoots of rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) plants, cultivated organically by small-scale farmers in Nieuwoudtville, are harvested for the production tea. These practices could lead to decreasing soil fertility. It was hypothesised that from plots will have lower nutrient concentrations than adjacent uncultivated plots. Soil and shoot samples were collected December 2005, 2006 2009 fields increasing plot age on three farms, analysed concentration. Compared with plots, no...
Although condensed tannins (CTs) are known to reduce forage intake by mammalian herbivores in controlled experiments, few studies have tested these effects the field. Thus role of CTs on foraging ecology free-ranging is inadequately understood. To investigate under natural savanna conditions, we pre-dosed groups goats with polyethylene glycol (PEG, a CT-neutralising chemical), CT powder or water before observing their behaviour. While accounting for season and time day, hypothesis that ways...
Understanding the effects of fire and herbivory on vegetation is crucial for biodiversity conservation in miombo woodlands. Changes regimes alter plant growth functional traits, such as carbon nitrogen content, specific leaf area (SLA), concentrations polyphenols, which can also change patterns these systems. We compared relative rate height basal diameter seedlings resprouts Julbernardia globiflora areas high low frequency presence absence herbivores Gorongosa National Park. measured traits...
AbstractColophospermum mopane trees are a common larval food plant of the moth (Imbrasia belina),which commonly reaches outbreak proportions. Our study investigated factors determining host tree choice by ovipositing moths within single species (C. mopane). Tree size was primary determinant oviposition at both habitat (tall riverine-, medium height woodland- and short-shrub mopane) individual scale, with an increase in number egg masses increasing (estimated canopy volume). Preference for...
Colophospermum mopane trees are a common larval food plant of the moth (Imbrasia belina), which commonly reaches outbreak proportions. Our study investigated factors determining host tree choice by ovipositing moths within single species (C. mopane). Tree size was primary determinant oviposition at both habitat (tall riverine-, medium height woodland- and short-shrub mopane) individual scale, with an increase in number egg masses increasing (estimated canopy volume). Preference for larger...
In this article we determine the effect of an extralimital megaherbivore on reproductive potential and vegetation structure two keystone tree species in Auob River south western Kalahari Desert southern Africa. Using spoor dung counts establish presence giraffe three predetermined density zones by walking 50 transects across river each zone. We also photographed six trees from zone use these photographs to browse impact potential, canopy volume as well percentage dieback extremities canopy....
ABSTRACT Insect herbivory plays a crucial role in shaping plant communities many terrestrial ecosystems. However, African savannas, insect has been relatively understudied compared to large mammalian herbivory. In this study, we examined the impact of herbivory, focusing on leaf chewers and miners, South savanna‐forest mosaic (including patches forest, thicket savanna) Hluhluwe iMfolozi Park, Africa. Our investigation spanned gradients rainfall, fire frequency mammal density. We surveyed...
Strategies and mechanisms are needed to enhance encroaching shrub species use by ruminants. Seriphium plumosum crude proteins, neutral detergent fibers, total phenolics, condensed tannins were determined from combined fine leaves stems collected during the dry wet seasons, burned unburned areas. S. protein was higher season on postburned Neutral fiber similar in both The mean phenolics respectively. These results have shown that forage quality is sufficient meet ruminants nutrient...
Abstract A trade-off between structural and chemical defences against herbivory in woody plants is alleged to depend on edaphic factors African savannas. We studied anti-herbivory traits, an mosaic of fertile infertile soils within a savanna landscape East Africa, towards elucidating defence traits expressions used data 81 for 8 species from sites — four (42 plants) another (39 plants). did not find general divide strategies our data. Instead, we found range combinations. Our results...