Clearing IAPs at Umdoni Park
Text by Kate Grieve, Wendy Neale and Rynardt Crous
Photos by G Grieve and R Boon
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| Flowers of Pereskia aculeata (R Boon) |
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| A cluster of fruits of Pereskia aculeata |
The Umdoni Park estate sweeps along the KZN mid south coast between Pennington in the north and the Mkumbane River in the south. The origins of the estate can be traced to one of the leaders in the sugar industry during colonial times, Sir Frank Reynolds, who lived at Lynton Hall. He appreciated the natural environment and often walked through the grasslands and forests from Lynton Hall, the Reynolds family home, to his office at the sugar mill. At Lynton Hall, Sir Frank established a beautiful heritage garden, obtaining plants imported by the Durban Botanical Gardens from Kew. In 1918, Sir Frank met with the Pennington brothers to negotiate a lease with the option to purchase 137 ha of land for Umdoni Park. Among the projects for the estate were the development of Botha House, a rail siding, a tidal pool and ladies’ change rooms as well a golf course. That year bush was cleared for the proposed golf course and the fairways were grassed a year later. In 1920 Sir Frank established the Umdoni Park Trust to manage and administer the finances of the estate, including Botha House and the golf course.
The Umdoni Park estate currently covers 210
ha. In addition to the golf course with its accompanying facilities and
sweeping greens, there are swathes of mature coastal forest and small patches
of grassland, both vegetation types of conservation concern.
In 2012 the problem of invasive alien
plants (IAP) at Umdoni Park was highlighted by Conrad Klusener (from Illovo
sugar) who agreed to sponsor efforts to remove them. The project was supported
by board member and tree enthusiast Dave Henry, to promote conservation of the
forest. To get the right person for the project, the newly appointed estate manager,
Rynardt Crous, contacted Wendy Neale, with whom he had worked previously at
Penn Valley golf estate. Wendy was initially employed for three days a week to
look after Umdoni Park and Lynton Hall. At that stage, public access to the
area was not controlled and the presence of people wandering over the course and in the forest was becoming a problem. At the time, Lynton Hall was occupied
by Ronald Munro-Ferguson, great grandson of Sir Frank Reynolds and patron of
Umdoni Park. Ronald and Rynardt agreed that an electric fence had become essential to protect the property. This was made possible by major sponsorship from Ronald as well as funding from Illovo, Umdoni Park Trust and the Pennington Conservancy, to ensure the whole property was fenced. With increased security, Wendy and Rynardt put in place their desire to improve
the walking trails and encourage visitors (and their donations, as well as the potential fort customer spin-off in the restaurant).
Wendy started working full time at Umdoni
Park in 2015. She inherited a team of four ladies who she trained and
supervised, although some of them were no longer able to cope with the
demanding physical work. After natural attrition of workers due to their advancing
age and re-deployment to more suitable positions, as well as the impact of
COVID, Wendy was able to put together a strong team of six workers. Solid support from management has facilitated the IAP clearance project. As of 2024,
she also mentors an intern from the local community, sponsored by Ronald. She has trained the team members in the
identification of IAPs and the correct methods to remove them. Her approach is
very much hands on and she is in the field with her team all the time. The
team’s enthusiasm for their task is evident in their keenness to learn the
names of the indigenous trees as well.
Initially the IAP clearance project was directed at the species commonly encountered in the area, such as yellow bells (Tecoma stans), Madeira vine (Anredera cordifolia) and cherry guava (Psidium cattleianum). Some of the species, such as Mexican sunflower (Tithonia diversifolia) and tree daisy (Montanoa hibiscifolia), have been completely eradicated from the estate, and there are only occasional sightings of others such as Cassia and Canna. The forest floor was congested with cherry guava and thousands have been removed.
It was Conrad Klusener who raised
awareness of the problem presented by the Barbados Cherry, Pereskia aculeata (also known locally as Pereskia). Once they started looking at it, Wendy and Rynardt were astounded to realise
the extent of the invasion of this species. Being a woody climber with clusters
of hard spines along the stem, it works its way into the forest canopy and
forms an impenetrable mass. Adding to its disagreeable nature, Pereskia can
re-sprout from the merest dry twig, even several years after cutting.
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| A mass of Pereskia aculeata fruits |
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| A dense infestation of Pereskia aculeata |
This spiny, succulent creeping plant was
introduced in South Africa form South America as an ornamental plant as well as
for (very effective) security fencing. It has been recorded in KwaZulu-Natal
from as early as 1881. Persekia aculeata is classified in the National Environmental
Management: Biodiversity Act, 2004 (act no. 10 of 2004) as a Category 1b
invasive species and by law, must be controlled.
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| The hook thorns on a shoot of Pereskia aculeata - enough to warn anyone form getting too close, and an effective deterrent to clearing activities |
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| Clusters of spines on a woody stalk of Pereskia aculeata which has already been severed in the process of clearing activities |
The fruits are edible, with birds and
others spreading the seeds widely. The plant is also very effective at
vegetative propagation. It has established itself in the KwaZulu-Natal coastal
regions and other tropical localities where it invades forest and other natural
vegetation, smothering areas and preventing access due to the protective
spines.
It soon became clear that removing Pereskia was going to require a major effort. Various methods were deployed, such as using fuel-soaked rags to burn the Persekia at the tops of the trees, and mechanical destruction of the plants with a TLB, without success. Over a three-year period, stem-wilter insects were introduced as a means of biological control but unfortunately, this intervention had little impact. Wendy then decided that a more aggressive approach was needed, taking guidance from Geoff Nichols and Elsa Pooley, and with Rynardt Crous’ support. Her method of dealing with the Pereskia is to cut and spray with herbicide, allow a period for the plant material to dry while other areas are treated with herbicide. Wendy had an extendable spray apparatus designed and built by her late husband, and paid for by her family, which allows her to spray herbicide on the Pereskia plants in inaccessible areas. In view of the possible risks, Wendy is the only person permitted to use this apparatus.
Once the treated material has dried, it is raked down and piled in heaps and left for a further period to dry fully before being burned. Follow up is very important and each area is re-visited several times to ensure that there are no remnants of the plants. This is no easy task but Wendy’s painstaking and dogged determination has proved very successful. Extensive areas of Pereskia have been removed, even from relatively inaccessible areas such as the steep sides of the Mkumbane river gorge.
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| A small fragment of Pereskia aculeata resprouting on the forest floor after a first round of clearing |
Clearing the Pereskia has allowed the
forest to recover. There appears to be very limited collateral damage from the
application of herbicide and with opening up the forest canopy, Wendy has noticed
more obvious flowering and has reported seeing the increased presence of
butterflies. Her dream is to have Pereskia in Umdoni Park under control in two
years and then to progress to the southern bank of the Mkumbane river.
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