A5015258862- Ecology and Vegetation Dynamics Studies
- Rangeland Management and Livestock Ecology
- Rangeland and Wildlife Management
- Wildlife Ecology and Conservation
- Botany and Plant Ecology Studies
- Plant and animal studies
- African Botany and Ecology Studies
- Botany, Ecology, and Taxonomy Studies
- Forest ecology and management
- Conservation, Biodiversity, and Resource Management
- Pasture and Agricultural Systems
- Plant Parasitism and Resistance
- Wildlife-Road Interactions and Conservation
- Library Collection Development and Digital Resources
- Species Distribution and Climate Change
- Land Use and Ecosystem Services
- Soil erosion and sediment transport
- Economic and Environmental Valuation
- Animal Ecology and Behavior Studies
- Avian ecology and behavior
- Ecosystem dynamics and resilience
- Agroforestry and silvopastoral systems
- Sustainable Development and Environmental Policy
- Mediterranean and Iberian flora and fauna
- Environmental Conservation and Management
Stantec (Canada)
2025
South African Environmental Observation Network
2015-2024
University of Cape Town
2010-2024
Eastern Washington University
2009-2018
Nelson Mandela University
2009-2016
Stellenbosch University
2002-2013
Helmholtz Centre for Environmental Research
1997-1998
University of Pretoria
1998
ABSTRACT Many introduced plant species rely on mutualisms in their new habitats to overcome barriers establishment and become naturalized and, some cases, invasive. Mutualisms involving animalmediated pollination seed dispersal, symbioses between roots microbiota often facilitate invasions. The spread of many alien plants, particularly woody ones, depends pollinator mutualisms. Most plants are well served by generalist pollinators (insects birds), limitation does not appear be a major...
Abstract. Question: In semi‐arid systems, rainfall gradients can cause plant‐plant interactions to shift from negative positive or vice versa. However, the importance of a second major abiotic factor, soil nutrients, has rarely been considered. We consider different combinations both factors and ask: do net adult‐seedling become less competitive more facilitative with increasing overall harshness? Location: Succulent Karoo, Western Cape, South Africa. Methods: examined between seedlings...
Many ecosystems have been transformed, or degraded by human use, and restoration offers an opportunity to recover services benefits, not mention intrinsic values. We assessed whether scientists practitioners use their projects demonstrate the benefits can provide in peer-reviewed publications. evaluated a sample of academic literature determine links are made explicit between ecological restoration, society, public policy related natural capital. analyzed 1,582 papers dealing with published...
Journal Article A Conceptual Model of Arid Rangeland Degradation: The escalating cost declining productivity Get access Suzanne J. Milton, Milton Search for other works by this author on: Oxford Academic Google Scholar W. Richard Dean, Dean Morné A. du Plessis, Plessis Roy Siegfried BioScience, Volume 44, Issue 2, February 1994, Pages 70–76, https://doi.org/10.2307/1312204 Published: 01 1994
1 In the debate on stability of savanna vegetation, spatial processes are often neglected. A simulation model based a cellular automata approach was constructed to identify factors and crucial coexistence trees grass, their effects arrangement in arid semiarid savannas. 2 The shows that traditional key determinants savannas rain, fire grazing generate sustain grasses only under specific conditions. 3 An increase rainfall (improved tree establishment) or (reduced competition from grass), led...
Foreword P. W. Roux Preface Acknowledgements Part I. The Driving Variables Dean and S. Milton: 1. climate of the Karoo - a functional approach Desmet R. Cowling 2. Soils arid south-western zone Africa M. Watkeys 3. Paleoenvironments Meadows 4. Plant biogeography, endemism diversity C. Hilton-Taylor 5. Biogeography, animals Vernon II. Form Function B. Lovegrove: 6. function in perennial plants G. Midgley F. van der Heyden 7. Functional aspects annual biennial Rooyen 8. reproductive ecology K....
Summary Savanna ecosystems show codominance of trees and grasses, the mechanisms involved in their coexistence remain unresolved. We investigated possible influence small‐scale heterogeneities disturbances determining tree spacing tree‐grass semi‐arid savannas, using a spatially explicit, grid‐based simulation model. added factors such as seed clumping, locally improved moisture conditions, vegetation clearing combinations all three these variables to previously published also examined...
We measured the field metabolic rate (FMR) and water influx (WIR) of largest species bird, Ostrich (Struthio camelus), which lives in Namib desert, one driest regions on earth. Along with doubly—labeled (DLW) measurements FMR WIR, we examined availability plants various habitats, selected by Ostriches, daily activity patterns these birds. During 6—8 d periods, adult Ostriches (88.25 kg) had an 18 040 kJ/d, while subadult birds (50.75 metabolized energy at a 15 428 kJ/d. Adult expenditure was...
Shrub encroachment is reducing the carrying capacity of arid grasslands in southern Africa for cattle. Although shrub-encroachment known to occur as a result selective overgrazing grasses by cattle, interactions between rainfall and grazing are not well understood. Both quantity sequence events likely influence growth rates competitive abilities shrubs grasses. slow process animals stocked at low densities regions. Thus, field experiments determining stocking that avoid shrub under various...
1. The influence of seed availability, weather and microsite on natural emergence survival seedlings was investigated over 38 months in arid shrubland the southern Karoo, South Africa, developed under < 200 mm annual precipitation. 2. Small-scale clearing herbivore exclusion experiments were conducted to test hypotheses that seedling growth unaffected by competition herbivory. 3. In undisturbed vegetation 20-800 m −2 emerged relatively cool humid austral autumn. Densities emerging greater...
Abstract Several Australian members of the genus Acacia L. have attained weed status in Cape Province, South Africa. It is shown that plants are pollinated but lack effective seed predators. Mature drop seeds numbering usually range 1 100 to 7 000 m−2yr−1. They a seed-bank soil about two five times this magnitude, 95 per cent which dormant. appears decline viability with age may be relatively very slow. These findings critical planning control-methods. (Miss S. J. Milton and Dr A. V. Hall,...
Summary 1. Up to 73% of the world’s rangelands are degraded, and increasing demand for meat in developing countries a growing human population likely exert even greater pressures on next 20–50 years. Restoration rangeland grazing potential resilience is therefore important, particularly face climate change. 2. We investigated influence past stocking rates (from 1910 1987), rainfall, current regimes 1988 2008) plant assemblages, potential, diversity palatable species southern Karoo...
Abstract. Sinking boreholes to tap groundwater supplies facilitated expansion of all‐year round livestock production into the semi‐arid Kalahari. Increased grazing and trampling pressure around often caused vegetation changes range degradation. The long‐term influences cattle on pattern watering points in southern part Kalahari are investigated using a grid‐based simulation model. Shrub‐grass dynamics modelled for two regimes with high low rainfall under various stocking rates. Results...
Abstract We evaluate the ability of existing models vegetation dynamics to explain how drought and herbivory by domestic livestock can change Karoo vegetation, why does not always return its original composition when are withdrawn. Using published data for arid southern semi‐arid eastern Karoo, we provide new conceptual these types discuss their relevance research into conservation rehabilitation rangelands.
Plant community dynamics in semiarid regions appear to be "event—driven." The aim of our model is attain an understanding the main processes determining spatial and temporal a shrub Karoo on large scale identify significant events that drive this community. Vegetation at study site covers 15—20% soil surface dominated by five shrubs: Brownanthus ciliatus (Mesembryanthemoideae), Ruschia spinosa (Ruschioideae), Galenia fruticosa (Aizoaceae), Pteronia pallens (Asteraceae), Osteospermum sinuatum...
The spatial distribution of plants is often thought to be an indicator underlying biotic and abiotic processes. However, there are relatively few examples patterns being analysed detect ecological process. Using the spacing savanna trees in southern Kalahari as example, we applied methods computer simulation modelling point pattern analysis evaluation their potential for identifying relevant generating processes from snapshot pattern. We compared real tree Kalahari, derived aerial...