Containment of the invasive Melaleuca hypericifolia (Red flowering tea tree) in Chapman’s Peak Slope in the Hout Bay area and in De Waal Drive in Cape Town
Melaleuca hypericifolia (native to Australia) is a fast growing serotinous shrub or small tree up to 6 m high. Leaves are green and arranged distinctively in opposite pairs at right angles to those above and below. Flowers are red and can be seen in Spring in South Africa. The plant often has a weeping growth habit and develops slightly papery bark as it matures. The species is currently listed as category 1a in the National Environmental Management Biodiversity Act (NEM:BA) regulations. Although it has been planted in a number of localities in Cape Town as an ornamental plant (mainly along roadsides where it does not spread), it was found naturalizing on the moist hill slope in Hout Bay (2012) and at De Waal Drive in Table Mountain National Park (2014), Cape Town. Because M. hypericifolia had been classified as a NEM:BA 1a, SANBI’s Invasive Species Programme, in collaboration with SANParks and City’s Early Detection Unit, were prompted to initiate a control project.
Photos: Melelauca hypericifolia leaves (taken by: CCT EDRR) and flowers (taken by: Lesley Henderson)
The Invasive Species Programme (ISP) and City of Cape Town’s Rapid Response Invasive Species Unit, with funds from the Working for Water Programme, initiated action during August - November 2012 to learn more about the extent of the population in Hout Bay and to contain the spread of this species. A contractor team of 12 people were employed to prevent the Hout Bay population from spreading. The aim was to control adult plants and remove seed pods before seed dispersal. Their work included data collection and involved taking GPS points of each individual plant, measured the height of the plants, canopy widths, stem base diameter, whether the plants were flowering at the time of data collection and the number of seed capsules present per plant and the treatment that was used to control the plants. Seed capsules were then collected and placed in plastic bags and incinerated at high temperature to kill the seeds. Seedlings were uprooted by hand and larger plants cut at the base of the stem and treated with 3% imazapyr herbicide mix. The contractor had not previously collected data of this nature nor used a GPS. The Western Cape SANBI-ISP staff and the City of Cape Town (EDRR staff) went to the field with them on their first day to train and assist the contractor with collecting, recording data and use of GPS. Approximately 1802 M. hypericifolia individuals were found and cleared in a condensed area of 20.4 ha along Chapman’s Peak Slope in the Hout Bay area. In 2014 another M. hypericifolia population was found naturalising at De Waal Drive in Table Mountain National Park. The same contractor that cleared the Hout Bay population is currently busy clearing this newly discovered population using the same method. The total number of plants that are in this site is still unknown. This contract constitutes part of an ongoing management plan. The future plan for this project is to employ contractors every year to conduct follow–up operations on these two populations within the Table Mountain National Park.
Top and bottom: City of Cape Town team monitoring Melelauca hypericifolia at De Waal Drive site (photos: CCT EDRR and ISP Western Cape)