Droughts Droughts damage grasslands more than expected scienceorfat

Droughts: Droughts damage grasslands more than expected science.orf.at


Droughts damage plants more than previously thought. According to an international study involving the University of Innsbruck, extreme droughts reduced plant growth by 60%. This far exceeds previously reported losses for grazing areas.

09/01/2024 12:35 pm

Online since today, 12:35 pm

“Overall, our results show with unprecedented precision that the global impact of the predicted increase in drought was significantly underestimated,” says the study published in the journal “PNAS”. Using a standardized approach, teams from six continents and one hundred locations simulated droughts for a year. These also included locations in Switzerland and Germany. Michael Bahn from the Institute of Ecology at the University of Innsbruck was also part of the extensive research team.

Experiments with meadows

As part of the study, for example, a team from the University of Agricultural, Forestry and Food Sciences at the Bern University of Applied Sciences (BFH-AFL) in Thun, Switzerland, covered six areas of meadow with Plexiglas slats, so that about 33 percent less rain could reach the ground than normal, as the university writes in a statement about the study. This exactly simulated the annual precipitation of the driest year in the last hundred years.

Another six areas of the same size, without Plexiglas coverage, were used for control purposes. Species composition and ecosystem function were recorded before, during and after the simulated drought. According to the study, plant growth was reduced by 60% in areas with artificial extreme droughts.

Important CO2 storage

BFH-HAFL emphasized that this knowledge about grasslands and shrub steppes is important. Because these ecosystems covered more than 40% of Earth's ice-free land area.

These findings are also important for climate change: “Since grasslands and forest-steppes store more than 30% of the global carbon stock, they are important as carbon sinks. If there are frequent droughts, these landscapes cannot always fulfill this CO2 binding function, which would increase climate change”, explained ecologist Andreas Stampfli, who was involved in the study, in the statement.