Wolwekraal Nature Reserve

Wolwekraal Nature Reserve is a protected area (113 ha) in South Africa’s Western Cape Province, located in the Municipality of Prince Albert. The Reserve protects an example of Prince Albert Succulent Karoo, an under-conserved and increasingly threatened vegetation type, rich in highly localized plant species. The property was acquired by Sue and Richard Dean in 2005, specifically for conservation purposes, and was declared a protected area in 2011. In 2013, it was officially added to the CapeNature Protected Area Network (https://www.capenature.co.za/news/2021/western-cape-protected-area-expansion-strategy-2021-2025) through an agreement between the owner and the Western Cape Department of Environmental Affairs. The agreement confers conservation status “in perpetuity” and transfers to any future owners.

In addition to protecting biodiversity and habitat on the property itself, the Nature Reserve conserves Indigenous cultural heritage and is dedicated to educational and research activities. A two-kilometre stretch of the Dorps River runs through the property and is used by birds, frogs, otters and other animals that move seasonally between the nearby Swartberg mountains and the plains below. The reserve forms part of the larger Gamka and Gouritz River catchments and falls within the UNESCO-designated Gouritz Cluster Biosphere Reserve (https://gouritz.com/about-gouritz-cluster-biosphere-reserve/).

Settlement of Indigenous nomadic hunter-gathers (Khoi) and herders (Khoe) are associated with the river where, they would have hunted game, harvested wood, and watered their livestock prior to European colonisation of this region in the 1770s. The scatters of artefacts on the open settlement sites include stone tools, bone, pottery, ostrich eggshell fragments and marine sea shell fragments. These are currently being studied under the supervision of Prof John Parkington of University of Cape Town with funding from the Rust Family Foundation (USA) and the GCBR (South Africa).Protection of biodiversity and cultural artefacts is achieved by through access control, the use of rangers who patrol the area on foot daily, and wi-fi enabled cameras and software that sends human images to the control centre mobile phones so that the rangers can rapidly respond to suspected intruders. Cameras and software donated by the Wildlife Protection Solutions (South Africa) and The Cactus and Succulent Society of America.

Scope of Activities

Wolwekraal Nature Reserve is managed through the Wolwekraal Conservation and Research Organisation (WCRO), a locally registered Public Benefit Organisation, in collaboration with Renu-Karoo Veld Restoration, an adjoining native plant nursery and ecological consulting business (see below).

Parts of the nature reserve that were degraded by overgrazing in the 19^th century are used for restoration research. The restoration trials function as a living laboratory for education activities including work experience mentoring. The information gathered from the trials is published and used to inform the restoration activities of Renu-Karoo Veld Restoration Nursery that serves clients throughout the arid Karoo region that makes up one third of South Africa. This vast arid region has a low population density and is home to less than half a million people who live in small rural villages or on vast isolated livestock or game ranges. Publications relevant to restoration are listed (with hyperlinks) on the EHN website and on https://wcro.co.za/research/   Wolwekraal Nature Reserve welcomes 400-500 visitors a year on guided walks.  At least 4,000 people visit the nursery every year.

WCRO regularly conducts free environmental education activities for primary school students and university groups, and hosts university students for short- and long-term research projects. WCRO also engages with the South African Environmental Observation Network (SAEON) to make monitoring data from the Reserve more widely available and to link ecological restoration activities on the Reserve with broader national aims.

 

Renu-Karoo, for its part,  https://renu-karoo.co.za/ serves the local community by supplying indigenous Karoo seeds and plants on the commercial market, providing sustainable employment opportunities for local people, and mentoring local people developing skills and knowledge to restore post-mining sites and mitigate and reverse some of the extensive livestock grazing damage in the Karoo. Renu-Karoo employs nine local people on a full-time basis to collect seeds, propagate plants, make compost, and sell plants. The nursery also occasionally employs part-time assistants for seed collection, sorting, and packing. Our service includes consulting where we advise landowners and companies on solutions for veld restoration. Renu-Karoo/WCRO also freely give advice on environmental and ecological issues to the local Municipality, to conservation agencies, farmers, and environmental action groups. They engage in local activities such as the annual Open Gardens event and engage actively with citizens and local government to promote sustainable living including recycling, compost making, and indigenous water-wise and wildlife-friendly gardens. A special school for teenagers with learning challenges (Prince Albert Skills School) uses the Renu-Karoo facilities to make compost for the school vegetable gardens.

 

Ecological Restoration Activities

Ecological restoration activities at Wolwekraal Nature Reserve include:

1. Field trials using different restoration methods. (In 2016 a large-scale brush packing and water retention experiment was established on eroded deep alluvium on the Reserve. This work, funded by the Missouri Botanical Garden, involved 25 post-grad students and their three mentors over three days. The students constructed brush-packed fences on eroded areas and dug large hollows to catch runoff water. The work was monitored in 2018 and again in 2020, revealing the use of the hollows to be more successful than the brush packing in leading to the establishment of vegetation. See Milton & Coetzee 2022 in https://grassland.org.za/sites/default/files/2023-11/March%202022.pdf

In 2017 a second large-scale brush packing and water retention experiment was established on skeletal soil overlying mudstone bedrock in a historically overgrazed and bare area of the Reserve. This study, funded by WCRO, took place during a prolonged drought. The site was monitored in 2018 and again in 2020. The response was less dramatic then on the deep-soil site; however, hollows, with or without brush packing, once again proved more effective for vegetation establishment than brush packing without hollows (Photo 2). We are also experimenting with the establishment of small-seeded, hygrochastic Aizoaceae added to bare and brush packed sites on skeletal soils as capsules. We are also experimenting with gypsum “seed bombs” to compare this seeding method with use of naked seeds that tend to be displaced by wind and water. As with bare seeds, seedling survival is totally dependant on follow-up rainfall.

In 2023/24 in collaboration with a Western Cape Department of Agriculture study of the effects of soil hollows of soil temperatures, we carried out additional sowing trials inside and outside of hollows, with and without brush packing and seeding. What happened?

Preliminary results indicate that brush packing in and out of hollows retains sown seeds. Digging hollows removed the annual and ephemeral seedbank restricted to the top 50 mm of soil. Perennials established better in the cooler, moister parts of hollows than on cleared flat ground. The negative effect of creating hollows is that nutrient-poor subsoil limited growth rate in hollows.

Unpublished leaflets and webinars on Karoo restoration are available on https://renu-karoo.co.za/seeds/

 

2. Seed orchards

Renu-Karoo cultivates some of the seeds that it supplies to clients in genetically diverse seed orchards. The land and water used for cultivation of the seed crops is privately-owned and loaned at no cost to Renu-Karoo by landowners who support the concept of ecological restoration.

3. Supervision of students.

WCRO/Renu-Karoo staff and members supervise interns and post-graduate students carrying out field trials and monitoring ecological restoration activities on Wolwekraal Nature Reserve and on other properties in arid parts of South Africa. For further information contact Sue Dean  [email protected] or Bertus Fourie [email protected]

4. Advisory services

Renu-Karoo/WCRO provide ecological advice and expertise for landowners, including livestock and wildlife farmers and the owners of other nature reserves, as well as engineering companies involved in resource extraction and ecological reconstruction. We advise on ecological restoration, re-establishment of forage plants, and establishment of natural vegetation on old fields and other damaged areas, as well as assessing carrying capacity for livestock and wildlife and conducting botanical surveys in the Karoo region.

5. Publications and information sharing

We publish our research conducted in peer-reviewed literature,and via popular articles in the local newspaper, blogs and posters. Our guided walks introduce a wide range of visitors to the diversity and sensitivity of arid areas and the need to rehabilitate the land.

Recent publications dealing with restoration, rehabilitation, conservation climate change and environmental health include:

Milton, S.J. & Dean, W.R.J. 2021. Anthropogenic impacts and implications for ecological restoration in the Karoo, South Africa. Anthropocene 36: Article 100307  https://doi.org/10.1016/j.ancene.2021.100307

Van der Merwe, H., Milton, S.J., Dean, W.R.J., O’Connor, T.G. & Henschel, J.R. 2021. Developing an environmental research platform in the Karoo at the Square Kilometre Array. South African Journal of Science 117(11/12): 99-105, Art. #10511. https://doi.org/10.17159/sajs.2021/10511

Milton, S.J., Short, S. & Dean, W.R.J. 2022. Decline in whistling rat (Parotomys brantsii) density: possible response to climate change in the Karoo, South Africa. African Journal of Ecology 90: 969-979. https://doi.org/10.1111/aje.13063

Milton, S.J., Petersen, H., Nampa, G., Van der Merwe, H., & Henschel, J.R. 2023. Drought as a driver of vegetation change in Succulent Karoo rangelands, South Africa. African Journal of Range and Forage Science 40:181-195. https://doi.org/10.2989/10220119.2021.1992501

Henschel, J.R., Duncan, F.D., du Toit, J.C.O., Milton, S.J. and van der Merwe, H. 2023. The brown locust refocussed - Knowns, unknowns and the relevance of Locustana pardalina (Walker) to Karoo ecosystems and rangeland management. Journal of Arid Environments 215, Art 105014 https://authors.elsevier.com/sd/article/S0140-1963(23)00085-X

Neethling, C.D., Milton, S.J., Buschke, F.T., Henschel, J.R., van Deventer, P.W., & Esterhuyse, S. 2023. A bioassay of mine-affected soils and ameliorants in semiarid rehabilitation. South African Journal of Plant and Soil 40: 227-239. https://doi.org/10.6084/m9.figshare.24917680.v1

Dean, W.R.J., Milton, S.J. 2024. Avian species assemblages in African mangrove forests, Ostrich 95: 71-82 https://doi.org/10.2989/00306525.2023.2263171

Milton, S.J., Clark, C., Hundermark, C.R., Hurt, C. and van der Merwe, H. 2024. Population trends in an endemic dwarf succulent over two decades: rainfall, elevation, microsite and landuse effects. Journal of Arid Environments 223: 10518. https://doi.org/10.1016/j.jaridenv.2024.105181

Milton, S.J. in press. African Journal of Range and Forage Science - paving the way to restoration in African rangeland. African Journal of Rane and Forage Science (in press 2024).

We plan to build an interpretation centre that houses a lecture room, library and displays. The facility will be used by school groups and anyone wanting to learn more about Karoo natural history, landuse, and restoration. Partial funding for the project was bequeathed by the WCRO founder, Richard Dean (https://doi.org/10.1016/j.jaridenv.2023.105000). Additional funds are currently being sought.

 

2009 - first of many student interns spend experiential training year at Wolwekraal Nature Reserve and in the indigenous plant nursery
2010 - first pilot restoration trials
2011 - declaration of Wolwekraal Nature Reserve as a gazette protected area
2013 - signed a MOU with SAEON establishing Wolwekraal as a formal research site
2016, 2017 - large-scale restoration trials carried out with post-grad student groups
2018-2020 - monitoring of large-scale restoration trials
2024 – comparisons of various combinations of hollows, brush packing and reseeding.

 

Plans for the Near Future

• 2025 – conversion of the PBO to a Trust. Construction of interpretation centre.
• 2025 - Formation of partnership to bring environmental education to local learners
• 2025 - Rewilding and restoration demonstrations on vacant lots in the village.

At Renu-Karoo we use the term “rewilding” to mean bringing the natural vegetation (veld) back to gardens, vacant lots and disturbed landscapes. Rewilding is a term used in South Africa to refer to the reintroduction of large predators, but in our PBO (Public Benefit Organization) and nursery business we consider that it is more important in most situations to bring back indigenous plants that support indigenous invertebrates such as bombyllid flies and solitary bees, that in turn support pollination and are prey for birds, reptiles and small mammals. A term for this is “food web restoration”.

We use the term restoration to refer to the re-establishing of natural cycles in damaged landscapes. These include resource capture (the improvement of rainwater infiltration and retention of organic matter and seeds by soil surfaces and vegetation), re-establishment of vegetation that resembles the original or reference vegetation in structure and composition, and reinstatement of food webs including decomposers, herbivores, parasites and predators and together maintain pattern and diversity.

 

Management Challenges and Opportunities

Wolwekraal Nature Reserve has a number of ongoing management challenges:

1. Water diversion: The river that runs through the Reserve is the major water source for the growing village population. River diversion for human use depleted the river during the long drought between 2015 and 2022, resulting in a loss of habitat and fauna.
2. Access control: The Reserve is only 3 km north of the village of Prince Albert. People sometimes enter the Nature Reserve to cut firewood or poach small game.
3. Garbage: The Reserve borders the municipal waste disposal facility. As such, garbage is continually carried onto the Reserve by wind, water, and people. This presents an ongoing challenge, but also an opportunity for community involvement. WCRO promotes recycling that will create jobs for local people and keep plastic out of our land and water.
4. Sewage effluent: The Reserve also borders the municipal sewage works. Effluent from the final clear water dam started flowing onto the Nature Reserve in 2009, giving rise to a dense reedbed that has replaced desert vegetation over an area of about 2 ha. This novel wetland habitat has altered the native ecology, but it has also sustained insects, amphibians, birds, and mammals through the eight-year drought when the river ran dry.
5. Invasive alien vegetation: Asian pink tamarix trees (Tamarix ramosissima) from village gardens have invaded the river bed and are costly and difficult to remove as the roots are embedded in the rocky river bed and resprout. River depletion increases salinity and alkalinity of the water, favouring alien over native riparian trees. The wood of these trees is not accepted as firewood for cooking or heating because of its sulphurous smell.
6. Feral animals: Feral dogs and cats from the village, attracted by the nearby waste disposal facility and lush habitat along the sewage effluent stream, move into the Nature Reserve and hunt birds, rodents, frogs, and reptiles. Feral domestic cats also hybridise with the African Wild Cat present in the nature reserve.
7. Climate change: A drought of unprecedented duration and severity has affected the central and southern region of the Karoo from January 2015 to December 2022. There is evidence that maximum and minimum temperatures are increasing. This is causing mortality among rare endemic plants, increasing poverty and natural resource dependence among local people, and hindering restoration trials.

 

Despite the challenges there are many opportunities:

1. Creation of meaningful training and employment opportunities for local Indigenous people as field rangers, tourist guides, restoration practitioners, plant propagators and shop assistants;
2. An outdoor education facility very near a village for school learners as well as for University students;
3. An opportunity to link restoration science with practice in a meaningful way by ensuring that advice provided to Karoo clients is based on locally conducted and relevant restoration science;
4. Through creation of local gardens featuring indigenous Karoo plants and our rewilding trials we interest and educate local gardeners about the environment that surrounds them;
5. Through demonstration of problems caused to wildlife and human health through poor management of sewage and waste, to activate our local community to take action and demand recycling and waste reduction management;
6. Through our guided walks and talks we can reach out to and inform a wide sector of society about the interdependence of soil, plants and animals and value of natural ecosystems in the Karoo to people;
7. Our work has attracted many young researchers from local and foreign universities. These are the conservation and restoration disciples spreading the word about the need to conserve, rehabilitate, restore and reconstruct Karoo ecosystems for the stability of the climate and the physical and psychological heath of our society.