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FEATURE

The Global Grassy Group team measuring grass functional traits at Cathedral When underground trees are damaged through ploughing, their woody
Peak in the Drakensberg. From left: Caroline Mashau, Bat Vorontsova, Gareth trunks and stems are ripped up and exposed to the surface. These tropical
Hempson, Lova Solofondranohatra. grasslands store as much carbon below ground as tropical woodlands do in
tree trunks above the ground.

TAKING THE LONG VIEW WHEN

RESTORING GRASSLANDS

BY PROF. SALLY ARCHIBALD, UNIVERSITY OF THE WITWATERSRAND

Restoration science and practice are critical in combatting the loss of old-growth

grasslands and the loss of biodiversity. Grassland restoration has often been
trampled underfoot in the rush to score carbon credits by planting trees, and
undermined by the assumption that degraded grasslands are easily fixed because
they are thought of as relatively young habitats.

n article in Science by Elise Buisson, was published in a special edition on Grass structure, as we cannot rely on restoration
Sally Archibald, Alessandra Fidelis of the journal, Science, in August 2022. to guide complete recovery after such
Aand Katharine N. Suding argues degradation,” say the authors.
strongly that restoration interventions Grasslands constitute almost 40% of
should be long-term, and benchmarked the terrestrial biosphere, and on top of Numerous studies across six continents
by an understanding of the complexities providing habitat for a great diversity show that secondary grasslands may take
of ancient grasslands. Such spaces have of plants and animals, contribute to the at least a century to recover their former
been built over centuries into ecosystems livelihoods of about one in eight people in species richness. Less is known about how
of high species diversity, whose resilience the world. Nevertheless, they are imperilled long it might take for below-ground soil
to climate change lies mostly out of sight, by massive land conversion for intensive and structure development, but it is likely
below the ground. The authors highlight agriculture and silviculture (forestry), to follow the same time line.
that land conversion – to cultivation or mining, woody encroachment and species
plantation forestry – is irreversible i.e. it invasion “driven by altered fire and grazing Research is vital in establishing the extent
is highly unlikely that these systems can regimes”. of the problem and the best way to
ever be restored to their old-growth state. resolve it. Scientists at the University of
Therefore, they argue that conversion Land use changes to mining or cultivation, Witwatersrand’s Future Ecosystems for
should be avoided wherever possible, but and altered disturbance regimes, put Africa programme, funded by Oppenheimer
also set out some practical restoration below-ground structures (e.g. bud banks) Generations Research and Conservation,
options for the Earth’s grassy ecosystems at risk of degradation. This is sufficiently are researching key questions regarding
that use knowledge of the unique needs serious to push grasslands over a threshold, grasslands restoration:
of their biodiversity to promote old-growth beyond which restoration may be
characteristics. difficult, or take decades to achieve. It is 1. Quantifying the extent of transformed
therefore imperative to protect old-growth grasslands in Africa.
The article, titled Ancient Grasslands Guide grasslands, “particularly from the threats 2. Quantifying the rates at which
Ambitious Goals In Grassland Restoration, that affect below-ground processes and biodiversity and soil carbon recovers

20 Landscape SA • Issue 118 2022