A “detection system” identifies ecosystems in difficulty

A new “resilience detection system” can identify ecosystems at risk of collapse, research shows.

The system uses satellites to pinpoint areas of concern – including those at risk of “tipping points” – and can also measure the success of conservation and restoration efforts.

Resilient ecosystems have a greater ability to recover from shocks such as droughts, fires and floods – so a decline in resilience makes an ecosystem more vulnerable.

The research team, led by the Global Systems Institute (GSI) at the University of Exeter, developed a prototype detection system.

Its first results suggest that global average resilience has declined over the past 20 years.

“By identifying regions that are losing resilience, this system shows us where we should be most concerned,” said GSI Director Professor Tim Lenton.

“It can raise a red flag, guiding action to restore resilience.

“This is especially important in places that might have a tipping point (a threshold that triggers irreversible change), like the Amazon rainforest.”

A recent study by the GSI team has shown that the Amazon rainforest is losing resilience – a “compliant” situation as it approaches a tipping point that could trigger dieback and turn much of the forest into savannah.

The new paper is based on regular measurements of the Normalized Difference Vegetation Index (NDVI) to see how ecosystems respond to changing conditions.

His findings, based on 20 years of NDVI data, include:

  • “Pronounced” loss of resilience in the Eastern Mediterranean, Central America and Caatinga (northeastern Brazil), all of which are experiencing prolonged drought.
  • The strongest trends in resilience decline are in tropical and subtropical dry broadleaf forests, montane grasslands and shrublands.
  • The study ‘zoomed in’ to South and East Asia and chose examples of regions where resilience has been lost: dry broadleaf forests in India, coniferous forests in China and a ‘great part” of the Mongolian steppe grasslands.

Professor Lenton said the detection system can measure the effectiveness of projects such as TIST, through which thousands of farmers have planted and protected millions of trees in four countries.

“You can see if these projects restore resilience to an ecosystem,” he said.

The system now needs to be developed further, and Professor Lenton said the inclusion of marine ecosystems (not just those on land) would be a big step forward.

The research team included the University of Montpellier, the Technical University of Munich and the Potsdam Institute for Climate Impact Research.

Funders included the Leverhulme Trust and the Alan Turing Institute.

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Material provided by University of Exeter. Note: Content may be edited for style and length.