Terrestrial ecosystems enhance root zones in response to intensified drought

Abstract

Adaptation of ecosystems root zones to climate change critically affects drought resilience and vegetation productivity. However, a global quantitative assessment of this mechanism is missing. Therefore, we analyzed observation-based data and found that the global average root zone water storage capacity (SR) increased by 11%, from 182 to 201 mm in 1982-2020. This increase amounts to 1657 billion m3 over the past four decades, affecting hydrological and ecological processes worldwide. SR increased in 9 out of 12 land cover types, while three relatively dry types experienced decreasing trends, potentially suggesting the crossing of ecosystem tipping points. Our results underscore the importance of considering root zone dynamics while analysing floods, droughts and carbon sequestration under climate change.