industry than before. This led to the introduction of many so-called “wonder plants”
that could yield multiple benefits for people and ecosystems, but that brought many
costs once they became invasive (Low 2012; Kull and Tassin 2012). For example,
Prosopis (Mesquite) was promoted in the apartheid era (mid-1900s) by agricultural
departments to solve the effects of drought in the arid Northern Cape (Shackleton
et al. 2014). Elderly community members recount stories of how agricultural
extension officers distributed Prosopis seedlings for planting on private farms and
in communal villages (Shackleton and Shackleton 2018). Leucaena leucocephala
(Leucaena), was promoted by development, agricultural and forestry-focused NGOs
during the 1960s to 1980s as a multipurpose tree (Brewbaker 1987). Similarly, a new
set of Australian Acacia species were introduced for dryland restoration (Carruthers
et al. 2011). Oreochromis niloticus (Nile Tilapia) was introduced into South Africa
in the 1950s for aquaculture, particularly for food security and income generation
among poor African communities (Zengeya et al. 2011).
The current ethos (in the post-apartheid democratic area) could facilitate further
purposeful introductions. For example, a shift in gardening practices to become less
water intensive might lead to the introduction of a new set of non-native species that
require little water or care, and yet may become invasive (van Kleunen et al. 2018).
Similarly, the rising demand for biofuels and green energy may lead to the promotion of invasive plants such as Jatropha curcas (Physic Nut) (Witt 2010; Blanchard
et al. 2011). Species of interest to collectors can easily be bought online
(e-commerce trade) which is a modern, easy and novel pathway of potential invasive
species (Martin and Coetzee 2011; Humair et al. 2015). Simultaneously, the growing
ethos of either managing or preventing invasions might lead to fewer purposeful
introductions (Carruthers et al. 2011; Udo et al. 2019), although the context of
increasing global movement of people and goods could lead to more accidental
introductions than in the past (Seebens et al. 2017). For example, biofouling and
ballast water has led to the recent introduction of a number of alien marine species
along the South African coastline (Faulkner et al. 2017, 2020, Chap. 12).
Overall, evidence from South Africa supports the proposition that there have been
clear changes over time in the ethos for introducing and promoting alien species
which follow trends in scientific, historical, political and economic contexts
(Carruthers et al. 2011). We illustrate this using a very broad set of temporal
scales—and there is further need for understanding and analysing changes at finer
spatial and temporal scales (e.g. Bennett 2015). Another important aspect would be
to analyse the role of different actors—i.e. maybe too much is contextualised under
the broad colonial banner and further comparison between British and Dutch settlers
might yield useful insights.
24.2.2 Proposition 1b: People Go to Great Lengths to Ensure
that Newly Introduced Species Become Well
Established
People have put effort into facilitating the establishment and spread of alien species.
For example, decades of research went into ensuring that introductions of
706
R. T. Shackleton et al.
that could yield multiple benefits for people and ecosystems, but that brought many
costs once they became invasive (Low 2012; Kull and Tassin 2012). For example,
Prosopis (Mesquite) was promoted in the apartheid era (mid-1900s) by agricultural
departments to solve the effects of drought in the arid Northern Cape (Shackleton
et al. 2014). Elderly community members recount stories of how agricultural
extension officers distributed Prosopis seedlings for planting on private farms and
in communal villages (Shackleton and Shackleton 2018). Leucaena leucocephala
(Leucaena), was promoted by development, agricultural and forestry-focused NGOs
during the 1960s to 1980s as a multipurpose tree (Brewbaker 1987). Similarly, a new
set of Australian Acacia species were introduced for dryland restoration (Carruthers
et al. 2011). Oreochromis niloticus (Nile Tilapia) was introduced into South Africa
in the 1950s for aquaculture, particularly for food security and income generation
among poor African communities (Zengeya et al. 2011).
The current ethos (in the post-apartheid democratic area) could facilitate further
purposeful introductions. For example, a shift in gardening practices to become less
water intensive might lead to the introduction of a new set of non-native species that
require little water or care, and yet may become invasive (van Kleunen et al. 2018).
Similarly, the rising demand for biofuels and green energy may lead to the promotion of invasive plants such as Jatropha curcas (Physic Nut) (Witt 2010; Blanchard
et al. 2011). Species of interest to collectors can easily be bought online
(e-commerce trade) which is a modern, easy and novel pathway of potential invasive
species (Martin and Coetzee 2011; Humair et al. 2015). Simultaneously, the growing
ethos of either managing or preventing invasions might lead to fewer purposeful
introductions (Carruthers et al. 2011; Udo et al. 2019), although the context of
increasing global movement of people and goods could lead to more accidental
introductions than in the past (Seebens et al. 2017). For example, biofouling and
ballast water has led to the recent introduction of a number of alien marine species
along the South African coastline (Faulkner et al. 2017, 2020, Chap. 12).
Overall, evidence from South Africa supports the proposition that there have been
clear changes over time in the ethos for introducing and promoting alien species
which follow trends in scientific, historical, political and economic contexts
(Carruthers et al. 2011). We illustrate this using a very broad set of temporal
scales—and there is further need for understanding and analysing changes at finer
spatial and temporal scales (e.g. Bennett 2015). Another important aspect would be
to analyse the role of different actors—i.e. maybe too much is contextualised under
the broad colonial banner and further comparison between British and Dutch settlers
might yield useful insights.
24.2.2 Proposition 1b: People Go to Great Lengths to Ensure
that Newly Introduced Species Become Well
Established
People have put effort into facilitating the establishment and spread of alien species.
For example, decades of research went into ensuring that introductions of
706
R. T. Shackleton et al.