Environmental Engineering Reference
In-Depth Information
Box 22.2 Investing in sustainability: a long-term, large-scale restoration
project in South Africa (based on Mills & Cowling 2006; Mills et al . 2007, 2010)
Subtropical succulent thicket, comprising a very
diverse and forest-like formation with the characteristic
tree or shrub spekboom ( Portulacaria afra ) as a key
species, is a type of vegetation unique to the south-
western part of the Eastern Cape province of South
Africa. This vegetation is rich in trees, shrubs, vines
and many other forms of plants, with a rich fauna as
well. It formerly covered an area of close to 1.4 million
hectares (Lechmere-Oertel et al . 2005), but after a
century of over-exploitation, mainly through injudicious
farming with angora goats, only about 200 000 hec-
tares of healthy intact bush remains. Apart from its
biodiversity value, the ecosystem services provided
are immense. The spekboom thicket protects the soil
from erosion and sustains water supply and quality to
large human populations. It supports a burgeoning
wildlife industry (including elephant and rhino) linked
to nature-based tourism, as well as numerous plant
and animal species of medicinal and cultural heritage
value. It is also a source of many plant species and
varieties grown worldwide as ornamentals. Moreover,
it is capable of capturing and storing considerable
amounts of carbon. These are reasons enough to
restore the desertifi ed areas and, happily, the degraded
thicket is remarkably amenable to restoration.
Due to the fact that planted cuttings of spekboom
readily take root and grow relatively rapidly, a healthy
stand of spekboom can be established within several
years, at least in areas where it formerly occurred. As
the re-established spekboom plants grow and begin
to establish the natural vegetation structure of the
thicket, other native shrubs, trees and herbaceous
plants are able to re-establish and the ecosystem
gradually recovers, even without irrigation. There is
evidence that some 50 years after the start of restora-
tion, the full complement of thickets shrub and tree
species is able to re-establish (van der Vyver et al .
unpubl. MS).
Restored sites have high potential for earning biodi-
versity credits. Even more signifi cantly, it is estimated
that, on average over a 30-year period, restored sites
can capture some 15.4 tons of carbon dioxide per
hectare per year. This could be traded for a similar
amount of credits on the international carbon market,
which should make the restoration entirely self-
fi nancing. This is a key condition for sustainability,
especially in a developing country like South Africa
(Mills et al . 2007).
To achieve all these remarkable sustainability
targets, deeper involvement by both the public and
private sectors is required. They will need to collabo-
rate in order to create the new institutions to convert
environmental and climate change challenges into
opportunities for development, and to implement the
large-scale projects required for sustainable restora-
tion and job creation. The potential is clear, and the
principles behind subtropical succulent thicket resto-
ration are a model for other restoration projects around
the world, as long as the right case-specifi c adjust-
ments are made.
Finally, we would like to cite Pavan Sukhdev, Special
Advisor and Head of UNEP's Green Economy Initiative,
and study leader of the TEEB project (2010, 2011;
Chapter 2): 'The greening of economies, including the
restoration of degraded ecosystems, is not and should
not be considered as a burden on economic growth;
instead it is a new engine for growth, employment, and
the reduction of persistent poverty.' In that same vein,
we here affi rm that the ecological restoration of
degraded ecosystems is a core element in society's
progress along the path away from profl igacy, and
towards prudence, justice and sustainability. We invite
our readers to join the effort to bring this vision a little
bit closer to reality in the coming years.
ACKNOWLEDGEMENTS
We are very grateful indeed to Paddy Woodworth for
his edits, comments and tough questions on three pre-
vious versions of this chapter. We also thank Richard
Cowling for checking and improving Box 22.2.
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