BIODIVERSITY CONSERVATION OF SPECIES AND ECOSYSTEMS
RESEARCH THEME QUESTIONS
Which species of plants and animals rely on and owe their survival to this conservation initiative?
- Is Tswalu large enough and what will be the minimum required size to ensure the ecological integrity of Tswalu in the future?
- What are the implications of reserve size for different species?
- What is the minimum reserve size required for species survival?
- How does Tswalu’s biodiversity compare with farms in the area under different management structures?
- How long does it take for a newly acquired farm to be restored?
- What contributions do new properties make to the overall environmental integrity of Tswalu?
- What happens in terms of succession – pioneer to climax species?
- Do we understand nature flux on Tswalu, compared with other adjoining properties?
Biological diversity at all levels is being lost at an unprecedented rate, many referring to the observed losses as the start of Earth’s sixth mass extinction episode. Factors such as habitat fragmentation and environmental degradation are influencing the distribution and abundance of species, often in ways that are impossible to predict. Conservation biology today faces a conundrum: how best to manage for species preservation and their habitats under rapidly changing and often unpredictable conditions. What is needed to help solve these challenges is conservation planning, based on accurate scientific data. For example, the impacts of fire, or lack thereof, in fire climax habitats are relatively well known, but the impacts in an already stressed, arid environment are not.
- Do we understand nutrient cycling in an arid environment?
- What is the grass-termite interaction in terms of nutrient cycling?
- What is the extent and impact on moribund vegetation and the overall condition of vegetation on Tswalu?
- Identifying the extent of local migratory species and the role of Tswalu in conserving them is important: what limits Tswalu’s ability to play a larger role in species conservation in this environment?
The presence or absence of large predators within a changing system is expected to trigger a cascade effect among animals and plants, one that will take decades of research to understand. The absence of lion (apex predators) will reduce predatory pressure on herbivores and, as a result, certain species may over-impact the vegetation. Limits of carrying capacities may be reached or exceeded, and movement reduced. Predator-prey avoidance will expect to have impacts on the trophic structure. The Tswalu divide between Korannaberg and Lekgaba provides the perfect opportunity to study cascade effects in a semi-arid environment.
Nowhere in the world do the benefits of cooperative breeding assist in the survival of a species as in arid environments. The need for increased search for food, nesting sites, anti-predator surveillance as well as the number of reduced breeding individuals to ensure the survival of progeny are not well understood. Age structure, behaviour relations between family members, reproductive success and interaction between dominant and sub-dominant animals in arid environments are poorly documented. Invertebrates have some of the greatest cooperative communal structures, the majority under-researched. Huge scope for research lies within arid-associated species.
Disease has the potential to impact species and populations on a global scale. Some diseases are endemic and/or indigenous, while others are introduced directly or via a series of exotic hosts.
What are the impacts of these diseases to species composition on Tswalu, and how are different species affected?
What are the implications for Tswalu?
What are the implications for the region?
Do we understand the relationships of the hosts?
Which environmental conditions are conducive to various diseases, and are there early environmental warning signs which can be detected?
What are the life cycles of diseases in the arid areas, compared with what we know from elsewhere in South Africa?
Which diseases are hosted within a population, and what are the environmental triggers for these outbreaks?
How do species within a population cope with such diseases?
Are there adaptations to disease?
What breaks a disease cycle?
What intervention, if any, is required by management for different species and different diseases?
There is a balance between predator-prey relationships in all environments. This is often a fine balance between the ability of the predator to outsmart the prey, and the prey’s ability to evade predation. At the top of the chain are the apex predators preying on a large variety of other species. However, the interesting and less understood relationships occur between the smaller species.