Effects of extreme drought on vital plant ecosystems

Despite evidence grasslands and shrublands can adapt to periods of moderate drought, they can’t withstand prolonged periods of extreme dryness, latest research shows.

An international collaboration, including researchers from Murdoch University, has found even native systems capable of acclimatising to moderate drought are no match for more extreme conditions.

Published in the journal Science, the research quantified the combined effects of drought on 74 grasslands and shrublands in locations across the world.

Researchers warn the findings foreshadow alarming impacts on vegetation as extreme drought becomes more common due to climate change.

The research found that while the grassland and shrubland productivity subject to moderate drought stabilised after the first year, extreme drought over several consecutive years significantly impacts plant growth.

Murdoch University Professor Rachel Standish, from Murdoch University’s School of Environmental and Conservation Sciences, said the findings were concerning for the future of  ecosystems, given the likelihood of increase extreme droughts due to climate change.

“We found that productivity reduced by 77% by year four when plants were subjected to consecutive years of extreme drought,” Professor Standish said.

“Grassland and shrubland ecosystems cover around 40% of the earth’s terrestrial surface.”

The research is part of International Drought Experiment which brings together researchers from across the world to measure the impact of reduce rainfall on ecosystems.

The full study Drought intensity and duration interact to magnify losses in primary productivity can be found in the journal Science.