trees improve streamflow when it adopted a policy of keeping a 20-m buffer zone
between a stream and a plantation with the aim of mitigating the effects of their
plantations on streamflow (Kruger and Bennett 2013, citing Malherbe 1968).
According to Kruger and Bennett (2013), public and scientific criticism of afforestation—mainly that it decreased streamflow in higher rainfall zones—reached a
crescendo prior to what they refer to as a seminal year in the history of
South African forest hydrology research—1935, when South Africa hosted the
Fourth Empire Forestry Conference which “brought together foresters from around
the British Empire to discuss current findings, to talk about problems and to
coordinate empire-wide policies.”
Kruger and Bennett (2013) believed that the 1935 Empire Forestry Conference
crystallised political support for the emerging major, long-term research programme
that would, among others, scientifically debunk the afforestation myths. Furthermore, in an early demand for evidence-based policy-making, the Conference provided a platform for politicians and critics of forestry to call for policies that were
evidence-based, practical and under constant review. With regards to evidence,
foresters agreed that in balancing theory and experience, experience should trump
theory until the theory was proved in practice—an unusual step at a time when
scientific theory generally enjoyed priority.
With reference to the concept of ‘faultless liability’ discussed above, it is important to note that in the 1880s and 1890s, in support of the ‘forestry has a positive
climatic and hydrological influence’ policy, the Cape Colony’s newly-founded
Department of Agriculture distributed seeds and plants freely or at little cost (Kruger
and Bennett 2013). Furthermore, from an invasive species management policy and
legislation perspective, unlike accidentally-introduced weeds like Xanthium
spinosum, many trees are examples of species which were intentionally introduced
with very different pathways of entry. Consequently one would expect different
regulatory approaches to the management of accidently and intentionally introduced
invasive species. However, as discussed in Sect. 18.8.2 below, this is not necessarily
the case.
18.5.2 The Jointed Cactus and Weeds Acts
The promulgation of the Jointed Cactus Eradication Act (Act 52 of 1934) marked a
subtle change in the legislative approach. Although the Act was still largely based on
the ‘identify and direct’ approach, it also contained a provision that was sensitive to
the issue of ‘faultless liability’. Other than simply putting the burden of eradication
on the occupier or owner of land, section 3 of the Act provides for the eradication of
Opuntia aurantiaca on private land by a designated official who is allowed to
“. . .take with him upon such land the labour, animals, vehicles, instruments, appliances, drugs or any other thing which in his opinion is necessary or required for the
purpose of eradicating such cactus.” After this initial clearing at no cost to the
occupier or land owner, a clearance certificate was issued (section 7) together with a
528
P. Lukey and J. Hall
between a stream and a plantation with the aim of mitigating the effects of their
plantations on streamflow (Kruger and Bennett 2013, citing Malherbe 1968).
According to Kruger and Bennett (2013), public and scientific criticism of afforestation—mainly that it decreased streamflow in higher rainfall zones—reached a
crescendo prior to what they refer to as a seminal year in the history of
South African forest hydrology research—1935, when South Africa hosted the
Fourth Empire Forestry Conference which “brought together foresters from around
the British Empire to discuss current findings, to talk about problems and to
coordinate empire-wide policies.”
Kruger and Bennett (2013) believed that the 1935 Empire Forestry Conference
crystallised political support for the emerging major, long-term research programme
that would, among others, scientifically debunk the afforestation myths. Furthermore, in an early demand for evidence-based policy-making, the Conference provided a platform for politicians and critics of forestry to call for policies that were
evidence-based, practical and under constant review. With regards to evidence,
foresters agreed that in balancing theory and experience, experience should trump
theory until the theory was proved in practice—an unusual step at a time when
scientific theory generally enjoyed priority.
With reference to the concept of ‘faultless liability’ discussed above, it is important to note that in the 1880s and 1890s, in support of the ‘forestry has a positive
climatic and hydrological influence’ policy, the Cape Colony’s newly-founded
Department of Agriculture distributed seeds and plants freely or at little cost (Kruger
and Bennett 2013). Furthermore, from an invasive species management policy and
legislation perspective, unlike accidentally-introduced weeds like Xanthium
spinosum, many trees are examples of species which were intentionally introduced
with very different pathways of entry. Consequently one would expect different
regulatory approaches to the management of accidently and intentionally introduced
invasive species. However, as discussed in Sect. 18.8.2 below, this is not necessarily
the case.
18.5.2 The Jointed Cactus and Weeds Acts
The promulgation of the Jointed Cactus Eradication Act (Act 52 of 1934) marked a
subtle change in the legislative approach. Although the Act was still largely based on
the ‘identify and direct’ approach, it also contained a provision that was sensitive to
the issue of ‘faultless liability’. Other than simply putting the burden of eradication
on the occupier or owner of land, section 3 of the Act provides for the eradication of
Opuntia aurantiaca on private land by a designated official who is allowed to
“. . .take with him upon such land the labour, animals, vehicles, instruments, appliances, drugs or any other thing which in his opinion is necessary or required for the
purpose of eradicating such cactus.” After this initial clearing at no cost to the
occupier or land owner, a clearance certificate was issued (section 7) together with a
528
P. Lukey and J. Hall