August 5, 2022
Introduction:
Conclusion (this is a news release, apparently issued by the University of Witwatersrand, therefore no need to worry about constraints in length related to copyright protection):(EurekAlert) 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.
An article in Science by Elise Buisson, Sally Archibald, Alessandra Fidelis and Katharine N. Suding argues strongly that restoration interventions should be long-term, and benchmarked by an understanding of the complexities of ancient grasslands. Such spaces have been built over centuries into ecosystems of high species diversity, whose resilience to climate change lies mostly out of sight, below the ground. The authors highlight that land conversion – to cultivation or plantation forestry – is irreversible: i.e. it is highly unlikely that these systems can ever be restored to their old-growth state. Therefore they argue that conversion should be avoided wherever possible, but also set out some practical restoration options for the Earth’s grassy ecosystems that use knowledge of the unique needs of their biodiversity to promote old-growth characteristics.
Grasslands constitute almost 40% of the terrestrial biosphere, and on top of providing habitat for a great diversity of plants and animals, contribute to the livelihoods of about one in eight people in the world. Nevertheless, they are imperilled by massive land conversion for intensive agriculture and silviculture (forestry), mining, woody encroachment and species invasion “driven by altered fire and grazing regimes”.
Land-use changes to, for example mining or cultivation, and altered disturbance regimes, put belowground structures (e.g. bud banks) at risk of degradation sufficiently serious to push grasslands over a threshold beyond which restoration may be difficult, or take decades to achieve. This makes it imperative to protect old-growth grasslands, “particularly from the threats that affect belowground processes and structure, as we cannot rely on restoration to guide complete recovery after such degradation,” say the authors.
Numerous studies across six continents show that secondary grasslands may take at least a century, “and more often millennia, to recover their former species richness”. Less is known about how long it might take for belowground soil and structure development, but it is likely to follow the same timeline.
Read more here: https://www.eurekalert.org/news-releases/961051In conclusion, they “urge conservation initiatives to safeguard against the conversion of old-growth grasslands for treeplanting or tillage agriculture, to maintain our ancient biodiverse grasslands with appropriate disturbance regimes, and to emphasise the long-term restoration of grasslands in efforts to restore Earth’s biodiversity”.