NEWS
tions and needs of different stakeholder
groups to minimise conflicts of interest.
The eucalyptus
River red gum became popular after
its introduction to South Africa around
1870. This was because it was useful for
a variety of products and services like
wood, shade and shelter.
Nowadays, river red gum is a major
problem along many river courses, es-
pecially in the Western Cape. Over the
past two decades the government has
spent more than R400 million trying to
clear the species.
However, little is known about the spe-
cies’ history in South Africa. Nor is very
much known about its exact abundance,
the specific environmental conditions
which trigger its invasion, and how as-
sociated pests and diseases might influ-
ence its future success as invader. This
lack of knowledge clearly hampers the
development of effective and sustain-
able management options.
Our work shows that river red gum is
a poster child example of a conflict-
generating species in the country. This
is because it brings benefits (such as
nectar and pollen for bees, habitat for
raptors, wood), but can also have huge
negative effects (such as alteration of
river structure, impact on local biodiver-
sity).
But management approaches have
mostly followed a “one-fits-all” phi-
losophy and proved in several cases
inefficient. Most approaches in invaded
riparian areas entail the removal of all
woody invasive plants with the assump-
tion that the ecosystem will recover by
itself.
Also, we found that the current legisla-
tive listing of river red gum is very com-
plicated and confusing. This makes the
enforcement of the listing for this spe-
cies difficult and has also the potential
to fuel conflicts of interest.
New approach needed
Our research shows that the complex-
ity that evolves around river red gum in
South Africa needs to be addressed in
future management options. Specifical-
ly, interventions must be regulated and
coordinated at national level as well as
regional and landscape scales.
And, to be effective, stakeholders (such
as beekeepers and landowners) need to
be encouraged to get involved to solve
conflicts of interests.
We also suggest options for improved
management approaches that use prin-
ciples of vegetation succession – that
is where trees are replaced over time
rather than simply cleared away. This
is a much more sustainable way of ap-
proaching the problem, particularly
where the restoration of the natural ri-
parian forest vegetation is the end goal.
Although this approach takes longer
than complete clearing, it’s more sus-
tainable because it allows for the de-
velopment of income-generating en-
trepreneurship and can help reduce
conflicts of interest.
We also recommended a simplification
of the legislative listing of river red gum.
Our work shows how important it is to
move away from demonising certain
species by considering not only what
impacts they have, but also their ben-
efits and geographic dynamics. Our
findings also show that it’s important
to engage with different stakeholder
groups to develop meaningful manage-
ment goals.
Overall, our review provides a blueprint
for the types of information needed for
developing management strategies
for non-native tree species in different
parts of the world.
Disclosure statement
Heidi Hirsch receives funding from the
Centre for Invasion Biology, Stellen-
bosch University, South Africa. She is a
member of the Australian Trees Work-
ing Group, South Africa.
Rietvlei wetland reserve (Photo: Abu Shawka) (https://www.farmersweekly.co.za/agri-technology/farming-for-tomorrow/
saving-land-importance-wetlands/)
Grassroots
Vol 20
No 1
March 2020
26