Post: Controlling Listed Alien and Invasive Species

March 17, 2022

– Roger Poole, TIPWG Chairman –

E V E R Y L A N D O W N E R ‘ S R E S P O N S I B I L I T Y

Biological invasions are a leading cause of global change and a major threat to South Africa’s environment and socio-economic development. This is according to Forestry South Africa’s (FSA) code of good practice for managing alien and invasive species in the South African forestry industry.

South Africa’s response to this issue has been widespread and substantial. Since 2013, the government has spent more than R1 billion annually on biosecurity and control projects and has listed 556 invasive taxa as requiring control. Currently there are approximately 800 problem plants and alien weeds in South Africa, of which 383 are listed as alien and invasive, and which must be controlled.

New alien and invasive species (AIS) lists
In September 2020, the Minister of Forestry, Fisheries and the Environment, gazetted a revised set of listed alien and invasive species that came into effect in March 2021.

The 2020 list provides for the following additional definitions:

“dormant plantation” means a plantation that has not been operational, functioning as a plantation or does not have a valid authorisation in terms of section 22(1)(a) or (b) of the National Water Act (NWA) for a period of 10 years, and where no reasonable attempt has been made to clear any listed invasive species.

“exempted from an existing plantation” means an existing plantation is exempt from requiring a permit for that specific species for any restricted activity in terms of National Environmental Management Biodiversity Act (NEMBA) or the alien and invasive species regulation, 2014.

“existing plantation” means a plantation which was operational, functioning and authorised to grow a specific listed invasive species in terms of section 22(1)(a) or (b) of NWA as September 2020 and does not include:

   (a) any extension to a plantation
   (b) any new plantations, or
   (c) any dormant plantation which was established or recommissioned after 18 October 2020.

“extension to a plantation” means the increase of the area of the plantation beyond the limits, area or location specified in
   (a) a permit issued in terms of NEMBA or the alien and invasive species regulations, 2014; or
   (b) an authorisation in terms of section 22(1)(a) or (b) of NWA; and
   (c) the size of such extension will trigger the requirement to obtain and environmental authorisation in
        terms of the National Environmental Management Act (NEMA).

Any plantation established up to 1 March 2021, does not require a permit under the AIS regulations, but any extension to an existing plantation after that date will require a permit and/or an environmental authorisation if the extension triggers the threshold of greater than one (1) hectare.

Notice 1 – sets out restricted activities relating to categories 1a, 1b, 2 and 3 of listed invasive species, which are either prohibited, exempt or require a permit in terms of the Biodiversity Act;

Notice 2 – sets out categories of exempted alien species that are within South Africa which will be exempted from the provisions of section 65(1) of the Biodiversity Act, in terms of which a permit is required to carry out a restricted activity involving a specimen of alien species; and

Notice 3 – provides the national lists of invasive species in terms of section 70(1) of the Biodiversity Act (Table 1 below) Commercial forestry species in an AIS context

Commercial forestry species in South Africa are included in List One. However, they are exempt from these regulations but only within a demarcated area provided the land user concerned had been authorised to use water in terms of the National Water Act, 1998.

In 2004, all commercial forestry species in South Africa were listed as alien and invasive species under NEMBA.

All landowners are thus legally responsible for controlling AIS, including any commercial forestry species, on their own land unless:

exempt for existing plantations under the NEMBA alien and invasive species regulations of 2004 and alien and invasive species lists of 2020; or
exempted under the Conservation of Agricultural Resources Act (CARA) regulations of 2001 provided the land user concerned has been authorised to use water in terms of the National Water Act, 1998. In general, all commercial plantations are exempt from the need for control when managed as a commercial tree crop but are required to be controlled outside any area authorised or demarcated as such.

TIPWG AIS standard operating procedure
To aid FSA members with the control of AIS, including commercial forestry species outside authorised/ demarcated areas, TIPWG has produced a standard operating procedure (Figure 1) based of the FSA code of good practice for managing alien and invasive species in the South African forestry industry.

In many ways, AIS control follows that of non-invasive weed and pest species, following an Integrated Pest Management (IPM) framework approach. This requires regular monitoring to identify changes in levels of pest population or damage and knowledge acquisition of the pest species and its interaction with the environment in which it is situated. This should include an understanding of the AIS life cycle, the damage it causes, limiting factors such as natural enemies and abiotic conditions that controls its spread. Once AIS threat is identified, the extent of the infestation should be evaluated using a four-point scale (see Figure 1).

As AIS control is a requirement of both NEMBA and CARA, the Integrated Pest Management (IPM) approach of taking ‘no action’ is no longer an option.

Landowners will need to undertake remedial action governed by a management plan with clear objectives that can be monitored and measured in terms of the outcomes and progress. Remedial action needs to be proportional to the scale of the infestation. In this respect, landowners need to consider the area needing treatment and the extent of the infestation across this area; the resources available and costs of control options; as well as the habitat restoration/re-vegetation requirements. When it comes to the restoration/re vegetation of sites previously occupied by AIS, the focus should be on the establishment of indigenous grass cover to minimise soil erosion and to implement a controlled fire regime that enhances, to some extent, the return of some biodiversity elements and suppresses the re-growth of AIS.

When considering the control methods available, landowners should follow an IPM approach which reflects non-agrochemical control option ahead of chemical control methods. This process should be documented, as it provides justification for the control method used.

As depicted in Figure 1, mechanical control options include the use of chainsaws and brush cutters to mechanically remove the AIS, as well as slashing, felling, uprooting and mulching together with controlled burns. These all have their benefits and limitations, with their use being highly dependent on the scale and geographic location of the infestation. If mechanical methods are deemed inadequate, then biological control options should be considered next. For some AIS (eg bug weed), the use of biological control agents (in this case G.decoris and A.santacruzi) can be used as a control measure – see TIPWG Bugweed Control IPM overview. However, for many AIS, there are currently no biological control agents available.

Chemical control should be a last resort, which when necessary is done in line with FSC pesticide policy and ESRA. The TIPWG approved pesticide list (APL) should be consulted to identify all possible chemical control agents. These then should be evaluated to ensure the most effective control agent with the least environment/social damage is selected. The Environmntal Social reisk assessment (ESRA) mitigations for each chemical control agent can be found on the TIPWG APL in the members section of the website.

Once a agrochemical control agent is selected, the landowner should READ THE LABEL even if it is a product regularly used. Label specifications and company policies on pesticide use should dictate the application process, with special consideration regarding application timings and whether a catchment approach is required.

The application of control measures, be it cultural, biological or agrochemical, should be done in three
stages:

Initial control application – the first attempt to control the infestation, be it a dense population of the target species, or simply a few scattered plants. Initial controls are seldom 100% effective, especially in dense infestations.
A follow-up control – the second attempt to control an invasive species and needs to be completed timeously (normally the next growing season) or the site can rapidly revert to its original infested state. This needs to continue until the infestation rate falls below 5%.
Maintenance control – when the infestation rate is <5% then maintenance control can be implemented It should be stressed that follow-up operations should be completed before implementing an initial control in another area.

Take-home message
Globally and locally, AIS pose a significant threat to biodiversity and ecosystem health. As landowners, it is our responsibility to ensure listed AIS are controlled on our landholdings. This should be done in a way that is sustainable, ensuring the effective long-term control of AIS without negatively impacting on the environment or human health. The TIPWG standard operating procedure provides a framework in which AIS control can be done sustainably, as well as a paper trail to justify why particular control actions were taken.