A Holistic Approach to Research
Research on Tswalu is guided by but not limited to the following three research themes:
1: Biodiversity Conservation OF Species and Ecosystem
Tswalu Kalahari Reserve performs an important role in the conservation of the arid southern Kalahari, and the subcontinent as a whole. This is achieved at Tswalu through a holistic approach which involves varied and targeted research, guided by, but not limited to, three themes:
- Which species of plants and animals rely 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.
2: Understanding the impacts of Climate Change in a semi-arid environment
During Earth’s long history, natural processes such as variations in solar radiation, orbital vicissitudes and even continental drift caused changes in temperature and rainfall patterns and inevitably impacted on biodiversity and species patterns and abundances. Climate change is thus regarded by many as a natural phenomenon.
More recently however, human actions (most notably the emission of greenhouse gasses) have accelerated the rate of climate change, leading to an unprecedented negative impact on biodiversity and ecosystem functioning. Even a 2°C warming can have a devastating effect on biodiversity, resulting in cascading effects and tipping points. Understanding impacts on biodiversity (including extinctions, range shifts, changes in distributions, hybridization and inter-species competition) and predicting threats to ecosystem services (health and food security) and extreme climate events (drought, flooding) is essential for biodiversity conservation, especially in the Kalahari, a region which is expected to show the first signs of actual die-offs and the impact of climate change.
Living in an arid environment requires many adaptions to survive. Different species adapt differently and interact with their environment in different ways. Identifying these adaptions within and between species is vital, in order to understand the long-term survival of species and ultimately the resilience of ecosystems. Tswalu provides a unique experiment in that it has been under conservation management for many years, compared with land newly designated from farming to conservation. In areas where land is overgrazed, the aridness scale is expected to be more severe.
- What are the key indicators and markers for rates of change (actual versus hypothetical)?
- Physiologically, how are different species adapted to an ever-harsher environment?
- What are the tipping points for different species?
- How have species adapted under different management practices?
- How do different species adapt under different climate circumstances?
- What are the tipping points for the various species?
- How do different species react to living in an arid environment?
- How do species react to the different seasons and associated climatic conditions?
- Which species are better adapted, and how?
- How do species living in the Kalahari use mutualistic relationships in order to survive?
3: Anthropogenic: The human impact - past, present and future
This involves documentation of archaeological sites on Tswalu and in the surrounding areas. There is a need to establish the human time line within the Kalahari, closely identifying the eras. These will form layers in our knowledge of the archaeology and palaeontology of the area. The use of current techniques in remote sensing to identify areas with fossil and other archaeological sites will add significantly to our understanding of the human impact on the Southern Kalahari.
- Do we understand early human involvement in the area – how did they survive and adapt to an ever-changing environment?
- What was the involvement of Bushman in the area, and what was their relationship with early pastoralists?
- How did early humans use the land?
- How did humans interact with the environment and other living species?
- What signs of this early interaction remain?
While humans always impact on the environment, understanding the extent of this impact, and identifying whether the impact is significant or not, is important. Species react differently to environmental impacts, some species tolerating high levels of interference, others showing marked reaction to very slight changes in their environment.
- Can we identify these stresses and measure the tolerances for different species?
- At what level does tourism impact a species negatively?
- Reactions to stress differ, and purely researching behaviour isn’t always an accurate measure: what are the physiological reactions of animals being handled or interacted with (for example, through capture or tourism)?
- Can the impact on animal behaviour be measured, and how?
- How is animal ability to survive compromised by capture or tourism?
- Humans place ever-larger demands on the occupation of wild places and usage of the animals that inhabit them; at what level is animal integrity compromised, and when is animal survival at risk?
- What are the anthropogenic barriers on the Kalahari landscape (fences, roads, water supply, etc.), and what are their short- and long-term implications for the ecology of Tswalu?
- What are the benefits of conservation to communities linked to Tswalu Kalahari Reserve, and what are the barriers to their longevity and ecological integrity?