Wednesday, 08 August 2018 20:21

Invasive Melaleuca hypericifolia removed from Hout Bay & Table Mountain National Park

Invasive Melaleuca hypericifolia (Red flowering tea tree) flowers.
Invasive Melaleuca hypericifolia (Red flowering tea tree) flowers. Ernita van Wyk
Invasive Melaleuca hypericifolia (Red flowering tea tree) flowers. Invasive Melaleuca hypericifolia (Red flowering tea tree) flowers. Ernita van Wyk

Have you seen the invasive Australian red flowering tea tree (Melaleuca hypericifolia) on your property?

The species is currently listed as Category 1a in the National Environmental Management Biodiversity Act (NEMBA) Alien and Invasive Species (AIS) Regulations (2014). Category 1a species must be removed. 

How do your recognise Melaleuca hypericifolia in Cape Town?

  • This invasive fast growing serotinous shrub or small tree reaches 6m in height. 
  • 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.

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

  •    A moist hill slope in Hout Bay (2012), Southern Cape Peninsula, Cape Town;
  •    Alongside De Waal Drive in Table Mountain National Park (2014), Cape Town.

History of containment in Cape Town

Because M. hypericifolia had been classified as a NEMBA 1a, SANBI’s Invasive Species Programme, in collaboration with SANParks and City’s Early Detection Unit, were prompted to initiate a control project in 2012. 

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.

i)  Hout Bay - 2012

Approximately 1802 specimens of M. hypericifolia plants were found and cleared in a condensed area of 20.4 ha along Chapman’s Peak Slope in the Hout Bay area.

  • 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. 

ii)  Table Mountain National Park - 2014

In 2014, another M. hypericifolia population was found naturalising alongside De Waal Drive in Table Mountain National Park (TMNP).

The same contractor that cleared the Hout Bay population was engaged to clear this newly discovered population using the same methods as those used in Hout Bay.

The future plan for this project  was to employ contractors every year to conduct follow–up operations on this population within the Table Mountain National Park.

M hypericifolia ErnitaVW PS

The invasive Australian red flowering tea tree (Melaleuca hypericifolia) found in TMNP. Pic: Ernita van Wyk. 

Melaleuca hypericifolia leaves Ernita van Wyk PS

The leaves of the invasive Australian red flowering tea tree (Melaleuca hypericifolia). Pic: Ernita van Wyk. 

 

Read 405 times Last modified on Saturday, 05 January 2019 22:28