Groundwater-dependent ecosystems are missing from global research and policy agendas

Xander Huggins , Melissa M Rohde, Robert Reinecke , Sebastian Gnann , Mattia Saccò, Grant C Hose, John C Stella, Björn Klöve 

A groundwater-dependent ecosystem (GDE) can be a stream or wetland sustained by groundwater, a terrestrial ecosystem that relies on groundwater for root water uptake, or the biodiversity that lives within aquifers. These ecosystems perform hydrological, ecological, and climate functions, and are meaningful to people through recreational, spiritual, and cultural practices. Traditionally studied at the local scale, GDEs are largely overlooked in global-scale research programmes and lack adequate incorporation in global environmental and sustainability policy agendas, despite holding vast potential to enhance their outcomes. Several global GDE studies have recently emerged, revealing that GDEs are globally prevalent and increasingly under threat. This Review synthesises early insights from these studies and argues that this emerging picture of GDE presence must be complemented by a dynamic, process-based understanding of GDE responses under multiple pressures. We outline policy agendas and Earth system frameworks that could be strengthened by the inclusion of GDEs and identify open questions to guide research in support of this shift.