Global study shows intensifying drought may wreck grasslands

The photo shows the autumn view of the Xilin Gol Grasslands in North China's Inner Mongolia autonomous region. [Photo provided to chinadaily.com.cn]

A 28-country collaborative study, spearheaded by a Chinese research team, has provided the first global evidence that as droughts become longer and more severe, grasslands worldwide do not simply adapt -- they tend to undergo breakdown.

Published this week in the journal Science, the study involved scientists from Beijing Forestry University and their counterparts from over 120 institutions, including Colorado State University in the United States. They tracked plant growth in 74 grasslands and shrublands across six continents during droughts.

The study provides the first global evidence that the combined effect of drought intensity and duration exacerbates productivity losses in grasslands and shrublands worldwide.

The researchers found that after four consecutive years of extreme drought, productivity losses increased by approximately 2.5 times compared with the first year. This suggests ecosystems could transition from a persistently low-yield state to a rapid downward spiral if climate change continues to prolong and exacerbate future droughts.

This study contributes to mounting evidence that future climate extremes will increasingly impact ecosystems in novel and concerning ways, according to Bianca Lopez, the journal's editor.

"By quantifying these relationships through a distributed global experiment, researchers establish a critical benchmark for future studies on drought severity and duration," commented the paper's peer reviewers.