21.8 Managing Conflict Species
21.8.1 Conflict Species in South Africa
Conflict-generating invasive alien species are defined as species that have relatively
high value for some people, while at the same time being capable of invading natural
vegetation and generating high levels of negative impact (van Wilgen and Richardson 2014; Zengeya et al. 2017). There are several prominent examples of such
species in South Africa (Table 21.2). The management of species that fall into this
category is complicated because opposing value systems have to be accommodated.
In South Africa, this issue has been addressed in a number of ways, discussed in the
sections below.
21.8.2 Catering for Conflict Species in Regulations
Species listed as invasive in South Africa’s A&IS Regulations have to be controlled,
and may not be cultivated or traded. However, permits will be granted for some
species (listed as Category 2) that have commercial value. These can be cultivated
and traded under permit, but the permit-holder can be held liable for spread of the
species. Some listed invasive species may be exempted from control requirements if
there are many individual plants that have significant ornamental value (Category 3).
These individual plants may be retained (e.g. in gardens), but may not be further
cultivated, traded, or replanted (i.e. the species are phased out rather than attempting
to actively remove them from private property). It is currently unclear whether or not
these regulatory approaches are effective (van Wilgen and Wilson 2018).
21.8.3 Using Biological Control Agents to Reduce Seed
Output
Proposals for the control of invasive Australian Acacia species were initially
strongly resisted by the wattle industry (Stubbings 1977). Ecologists working in
the field of biological control subsequently proposed the use of seed-feeding and
gall-forming agents for these trees, and these were released following protracted
negotiations with representatives of the wattle industry. These agents have been
markedly successful in reducing seed output (Moran and Hoffmann 2012), and have
substantially slowed the spread of these species in many areas (Henderson and
Wilson 2017; Hill et al. 2020b, Chap. 19).
21 The Extent and Effectiveness of Alien Plant Control Projects in South Africa
617
21.8.1 Conflict Species in South Africa
Conflict-generating invasive alien species are defined as species that have relatively
high value for some people, while at the same time being capable of invading natural
vegetation and generating high levels of negative impact (van Wilgen and Richardson 2014; Zengeya et al. 2017). There are several prominent examples of such
species in South Africa (Table 21.2). The management of species that fall into this
category is complicated because opposing value systems have to be accommodated.
In South Africa, this issue has been addressed in a number of ways, discussed in the
sections below.
21.8.2 Catering for Conflict Species in Regulations
Species listed as invasive in South Africa’s A&IS Regulations have to be controlled,
and may not be cultivated or traded. However, permits will be granted for some
species (listed as Category 2) that have commercial value. These can be cultivated
and traded under permit, but the permit-holder can be held liable for spread of the
species. Some listed invasive species may be exempted from control requirements if
there are many individual plants that have significant ornamental value (Category 3).
These individual plants may be retained (e.g. in gardens), but may not be further
cultivated, traded, or replanted (i.e. the species are phased out rather than attempting
to actively remove them from private property). It is currently unclear whether or not
these regulatory approaches are effective (van Wilgen and Wilson 2018).
21.8.3 Using Biological Control Agents to Reduce Seed
Output
Proposals for the control of invasive Australian Acacia species were initially
strongly resisted by the wattle industry (Stubbings 1977). Ecologists working in
the field of biological control subsequently proposed the use of seed-feeding and
gall-forming agents for these trees, and these were released following protracted
negotiations with representatives of the wattle industry. These agents have been
markedly successful in reducing seed output (Moran and Hoffmann 2012), and have
substantially slowed the spread of these species in many areas (Henderson and
Wilson 2017; Hill et al. 2020b, Chap. 19).
21 The Extent and Effectiveness of Alien Plant Control Projects in South Africa
617