Groundwater-dependent ecosystem map exposes global dryland protection needs

Groundwater’s role in supporting ecosystems worldwide is rarely acknowledged. Groundwater-dependent ecosystems (GDEs), which depend on groundwater for some or all of their water needs, are diverse and include desert springs, mountain meadows and streams, coastal wetlands and forests. However, the location of these ecosystems worldwide has been largely unknown, hindering our ability to track impacts, establish protective policies, and implement conservation projects.Here, leveraging Earth Observation datasets, random forest modelling, and multiple national and state-level GDE mapping initiatives, we map GDEs across global drylands at high resolution (1 arc-second, roughly 30 m pixels). We find GDEs present on over 8.3 million km2 -- more than one-third of areas analyzed, including important biodiversity hotspots. GDEs are found to be more extensive and contiguous in pastoral landscapes with lower rates of groundwater depletion, suggesting that many GDEs are likely to have already been lost due to land and water use practices. Over half of GDEs exist within regions showing declining trends in regional groundwater storage, and only one-fifth of GDEs exist on protected lands or in jurisdictions with sustainable groundwater management policies, invoking a call to action to protect these vital ecosystems.Cultural and socio-economic linkages with GDEs further underpin these protection needs. The Greater Sahel serves as a case study of these factors, where GDEs play an essential role in supporting biodiversity and rural livelihoods, and which we use as a basis to discuss other means for GDE protection in politically unstable regions. Our GDE map provides critical information for prioritizing and developing policies and protection mechanisms across various local, regional or international scales to safeguard these important ecosystems and the societies dependent on them. An interactive version of our global GDE and GDE probability maps are available at https://codefornature.projects.earthengine.app/view/global-gde. ReferenceRohde, M.M., Albano, C.M., Huggins, X. et al. Groundwater-dependent ecosystem map exposes global dryland protection needs. Nature 632, 101–107 (2024). https://doi.org/10.1038/s41586-024-07702-8