California is struggling to manage groundwater, which is crucial for crop irrigation and drinking water.
Now, a study from UC Santa Barbara highlights another role of groundwater: protecting diverse ecosystems from drought.
UCSB researchers examined 38 years of satellite imagery and water data to understand how changes in groundwater levels affected surrounding environments.
According to co-author and UCSB Geography Professor Dar Roberts, plants thrive when water is not much deeper than their roots.
“As the groundwater becomes deeper, harder to access by plants, you see more and more of a negative impact,” Roberts said.
The study found that ecosystems were healthiest when groundwater levels remained within one meter of the plants' deepest roots. During droughts, groundwater also served as a protective shield for these environments by preventing them from drying out.
Roberts urged policymakers drafting management plans to consider native plants’ access to groundwater.
“As we attempt to do a better job with sustainable water use, it's knowing how the natural vegetation is being impacted,” Roberts said.
He also hopes to extend this work beyond California.
