commercial forestry and freshwater fish for recreational angling) that have become
invasive have led to vociferous disagreement as to how they should be managed (van
Wilgen and Richardson 2014; Woodford et al. 2016).
South Africa’s attempts at regulation began in 1861 with the passing of an Act
requiring the control of the invasive Bur Weed (Xanthium spinosum). Many similar
acts followed (Richardson et al. 2003; Lukey and Hall 2020, Chap. 18), usually with
a focus on a particular species, or set of species, and holding landowners responsible
for controlling the species concerned (Lukey and Hall 2020, Chap. 18).
Active management of biological invasions in South Africa arguably began in
1913 with the release of the Cochineal Insect (Dactylopius ceylonicus) to control
Drooping Prickly Pear (Opuntia monacantha). This was the first release of a
biological control agent in South Africa (Moran et al. 2013). The later release of
biological control agents against Opuntia ficus-indica (Mission Prickly Pear) led to
spectacular success, and biological control of invasive alien plants was to become an
effective method for reducing populations of several important invasive plants.
In 1934, the Jointed Cactus Eradication Act (Act 52 of 1934) was promulgated.
This Act marked a change in the legislative approach (facilitating a more statecoordinated, programmatic and integrated approach), and it was followed by a
largely successful suite of management interventions, including biological control
and mechanical clearing (Moran and Annecke 1979).
Despite the early biological control successes against invasive Opuntia species in
the 1920s and 1930s, by 1945 people were becoming concerned about other invasive
alien species, particularly in the Western Cape. These concerns were addressed, inter
alia, in a publication of the Royal Society of South Africa on the preservation of the
vegetation of the Fynbos Biome (Wicht 1945). It was the first scientific report to
consider the management of invasive species in South Africa, and noted that
invasive tree species were “one of the greatest, if not the greatest, threats” to the
conservation of vegetation in the Fynbos Biome. Concerns about invasive plants
continued to grow, mainly in the Fynbos Biome (Anon. 1959; Stirton 1978). In
1970, the Mountain Catchment Areas Act (Act 63 of 1970) was published. This Act
authorised, within 5 km of the boundary of a proclaimed mountain catchment area,
“the destruction of vegetation which is, in the opinion of the Minister, intruding
vegetation” (the term “intruding vegetation” referred to invasions by alien plants).
The Mountain Catchment Areas Act thus empowered the Minister not only to clear
invasive species from formally protected areas, but also to extend these control
operations to 5 km beyond the boundaries of proclaimed areas. In the 1970s, the
Department of Forestry, backed by the Mountain Catchment Areas Act, embarked
on very ambitious projects to clear invasive plants from mountain catchment areas in
the Fynbos Biome. These co-ordinated alien plant clearing projects in mountain
catchment areas in the Western Cape were the first concerted, long-term alien plant
control operations at a provincial scale (Wicht and Kruger 1973; Fenn 1980).
Invasive species have also been actively managed in the Kruger National Park
since the 1950s (Foxcroft and Freitag-Ronaldson 2007), and the Department of
Forestry and its successors have implemented large-scale alien plant control operations since the 1970s (Wicht and Kruger 1973).
1 Biological Invasions in South Africa: An Overview
13
invasive have led to vociferous disagreement as to how they should be managed (van
Wilgen and Richardson 2014; Woodford et al. 2016).
South Africa’s attempts at regulation began in 1861 with the passing of an Act
requiring the control of the invasive Bur Weed (Xanthium spinosum). Many similar
acts followed (Richardson et al. 2003; Lukey and Hall 2020, Chap. 18), usually with
a focus on a particular species, or set of species, and holding landowners responsible
for controlling the species concerned (Lukey and Hall 2020, Chap. 18).
Active management of biological invasions in South Africa arguably began in
1913 with the release of the Cochineal Insect (Dactylopius ceylonicus) to control
Drooping Prickly Pear (Opuntia monacantha). This was the first release of a
biological control agent in South Africa (Moran et al. 2013). The later release of
biological control agents against Opuntia ficus-indica (Mission Prickly Pear) led to
spectacular success, and biological control of invasive alien plants was to become an
effective method for reducing populations of several important invasive plants.
In 1934, the Jointed Cactus Eradication Act (Act 52 of 1934) was promulgated.
This Act marked a change in the legislative approach (facilitating a more statecoordinated, programmatic and integrated approach), and it was followed by a
largely successful suite of management interventions, including biological control
and mechanical clearing (Moran and Annecke 1979).
Despite the early biological control successes against invasive Opuntia species in
the 1920s and 1930s, by 1945 people were becoming concerned about other invasive
alien species, particularly in the Western Cape. These concerns were addressed, inter
alia, in a publication of the Royal Society of South Africa on the preservation of the
vegetation of the Fynbos Biome (Wicht 1945). It was the first scientific report to
consider the management of invasive species in South Africa, and noted that
invasive tree species were “one of the greatest, if not the greatest, threats” to the
conservation of vegetation in the Fynbos Biome. Concerns about invasive plants
continued to grow, mainly in the Fynbos Biome (Anon. 1959; Stirton 1978). In
1970, the Mountain Catchment Areas Act (Act 63 of 1970) was published. This Act
authorised, within 5 km of the boundary of a proclaimed mountain catchment area,
“the destruction of vegetation which is, in the opinion of the Minister, intruding
vegetation” (the term “intruding vegetation” referred to invasions by alien plants).
The Mountain Catchment Areas Act thus empowered the Minister not only to clear
invasive species from formally protected areas, but also to extend these control
operations to 5 km beyond the boundaries of proclaimed areas. In the 1970s, the
Department of Forestry, backed by the Mountain Catchment Areas Act, embarked
on very ambitious projects to clear invasive plants from mountain catchment areas in
the Fynbos Biome. These co-ordinated alien plant clearing projects in mountain
catchment areas in the Western Cape were the first concerted, long-term alien plant
control operations at a provincial scale (Wicht and Kruger 1973; Fenn 1980).
Invasive species have also been actively managed in the Kruger National Park
since the 1950s (Foxcroft and Freitag-Ronaldson 2007), and the Department of
Forestry and its successors have implemented large-scale alien plant control operations since the 1970s (Wicht and Kruger 1973).
1 Biological Invasions in South Africa: An Overview
13