#05 2025
By Helga van der Merwe, Nanette van Staden and Sue Milton (SAEON Research Associate, Wolwekraal Conservation and Research Organisation): NRF-SAEON Arid Lands Node
Imagine arriving in Prince Albert after leaving the lush green grasslands of Potchefstroom, only to be met with a landscape of dwarf succulents, hardy shrubs, endless horizons ─ and a silence that lingers for days. For the North-West University (NWU) lecturers and students, the Karoo was both a challenge and a revelation…
A relatively recent collaboration between the Arid Lands Node (ALN) and NWU was expanded and strengthened. In September the node hosted a group of NWU postgraduate students and lecturers on a field excursion to Tierberg-LTER and Wolwekraal Nature Reserve. These two SAEON research platforms, just outside the small and charming town of Prince Albert in the Succulent Karoo, provided the ideal location to demonstrate different field methodologies and illustrate plant functional traits found in species adapted to arid environments.
Functional ecology is concerned with the roles that species play within their communities and ecosystems. We use traits in plants and animals to better understand how these roles fit together and keep an ecosystem running. Think of it like a play with different actors but each with their unique role: some species provide shade and nurse little seedlings; others are experts at storing water and some are champions in self-defence against herbivory. By focusing on functional traits, rather than every individual species, we can break down an ecosystem into its functional components.
This approach was what brought the NWU group from the grassy Savanna and Grassland biomes of Potchefstroom to the succulent dominated dwarf shrublands of the Succulent Karoo Biome.
Five honours students, one MSc student, two postdocs, three lecturers from the Department of Botany at NWU (including the excursion leader, Prof. Frances Siebert), the ALN scientist (Prof. Helga van der Merwe) and ALN postdoc (Dr Nanette van Staden) as well as SAEON research associate Dr Sue Milton were part of the group that were going to tackle resurveying vegetation plots at both research sites under challenging dry conditions.
The Wolwekraal group, the ‘Wolwe’ (wolves), led by Sue Milton. (Photo: Irene Coetzee)
The Tierberg group, the ‘Tiere’ (tigers) led by Helga van der Merwe. (Photo: Nanette van Staden)
The NWU group was divided into two teams. One was responsible for undertaking the surveys at Tierberg-LTER and the other at Wolwekraal Nature Reserve. However, both teams were given the opportunity to visit and take part in the different field methodologies undertaken at each research platform.
The project resurveyed at Tierberg-LTER was an experiment to assess the effects of fire in a fire-free ecosystem, following the invasion of an alien perennial grass (Pennisetum setaceum) in indigenous Prince Albert Succulent Karoo vegetation. Control and burn plots were marked in the landscape and surveyed before the induced fire and the burn plots burnt under two fuel loads (high and low fuel loads) in 2006. Vegetation surveys using the line intercept method and abundance counts per species in 1 x 1 m plots were conducted before the burn plots were exposed to the fire treatments. Subsequently, vegetation surveys on both control and burn plots were repeated in 2006, 2008 and 2014. The 2025 repeat surveys captured the characteristics of the vegetation 19 years after fire.
Sue (second from the left) assisting the students with seedling identification. (Photo: Nanette van Staden)
The small things count. (Photo: Nanette van Staden)
Tierberg team members assisting Helga with species counts in a quadrat. (Photo: Nanette van Staden)
On Wolwekraal Nature Reserve, seedling establishment was resurveyed within a larger vegetation monitoring project initiated in 2010. The 5 x 5 m plots were monitored during drought (2016, 2019, 2021, 2022) and after drought-breaking rains in 2023 and 2024. In 2024, seedlings (<10 leaves) were counted per species in one square metre in the south-east corner of each 5 m x 5 m plot. In 2025 the seedlings in the south-east and north-west corners were counted in one square metre plots within the larger 5 m x 5 m plots to quantify the number of seedlings in the landscape following a dry period (75 mm of rain received from 1 January 2025 until resurvey).
The students were responsible for data capturing in the evenings. Initial data analysis took place once the data were captured, supported by NWU and SAEON staff and postdocs. The students presented their initial findings on their last evening in Prince Albert, and these were discussed. Additional analyses will be conducted, and the students will present their findings at a mini symposium.
The Tiere (“tigers from Tierberg”) and Wolwe (“wolves from Wolwekraal”) united at Tierberg. (Photo: Nanette van Staden)
The North-West University and SAEON Arid Lands Node excursion group. (Photo: Abraham Ryke)
Practical fieldwork experience is crucial in the development of skilled researchers in the environmental sciences. Often such opportunities are lacking at tertiary-level because of cost constraints, but the NWU group used the opportunity to the maximum to learn as much as they could about the Karoo environment, scientific methods and statistical analysis. The students were inquisitive, receptive to guidance, dedicated and diligent until the very end of their field work – providing a positive prospect for the next generation of early-career researchers.
As climate change continues to reshape the Karoo, long-term monitoring and experiments like these not only uncover the hidden resilience of its plants but also inspire the next generation of scientists who will eventually carry this work forward.
