Drylands occupy more than 40 per cent of the global land surface

ILRI/Andrew Mude

The impacts of climate change and desertification on drylands could be reduced by preserving biodiversity, one of the first studies to look at dryland biodiversity and ecosystems has found.

This, in turn, would help protect the livelihoods of more than a third of the global population.

Drylands occupy more than 40 per cent of the global land surface. They host around a fifth of the major centres of global plant diversity and more than a third of endemic bird areas — home to birds that live in geographically restricted areas.

"Biodiversity has an important effect on the quality and quantity of the ecosystem services provided by drylands," Fernando Maestre, an ecologist at the King Juan Carlos University, Spain, and lead author of the study — published in Science last week (13 January) — told SciDev.Net.

These crucial services include carbon storage and the build-up of nutrient pools, all of which are crucial to prevent negative impacts of climate change and desertification.

Researchers looked at 14 of these functions in more than 200 dryland ecosystems in 16 countries.  

They found that the richness of biodiversity had a larger influence on the ability of dryland ecosystems to maintain these functions, than factors such annual rainfall levels or microbes in the soil.

Maestre said the findings seemed particularly relevant for ecosystem functions linked to carbon and nitrogen cycling.

"Because land degradation is often accompanied by the loss of soil fertility, plant species richness may also promote ecosystem resistance to desertification," he said.

John Lemons, professor emeritus of biology and environmental studies at the University of New England, United States, told SciDev.Net that the study was the first to determine the relationship between dryland biodiversity and multiple ecosystem functions.

More than a third of the global population lives in drylands so the preservation of their biodiversity is crucial for their livelihoods, added Maestre.

"This kind of study would be of enormous assistance to countries trying to implement biodiversity plans under the UN Convention on Biodiversity," said Lemons.

Writing in an accompanying perspective, also published in Science, Guy Midgley, of the South African National Biodiversity Institute and University of KwaZulu-Natal, South Africa, said that the study had taken an important step towards understanding the relationship between biodiversity and ecosystem function.

The study "has global relevance, and is especially valuable for many developing and least-developed countries facing desertification trends," he said.

Link to full paper in Science
Link to perspective in Science