Groundwater-dependent ecosystem map exposes global dryland protection needs.

Area of Science:

• Environmental Science
• Ecology
• Hydrology

Background:

• Groundwater is a critical freshwater source globally, yet its role in supporting ecosystems is often overlooked.
• The extent and location of groundwater-dependent ecosystems (GDEs) are largely unknown, hindering conservation efforts.
• Existing protection measures for GDEs are insufficient to address threats like groundwater depletion.

Purpose of the Study:

• To map groundwater-dependent ecosystems (GDEs) globally at high resolution.
• To assess the extent of GDEs in drylands and their overlap with biodiversity hotspots.
• To evaluate the current protection status of GDEs and identify regions at risk from groundwater depletion.

Main Methods:

• High-resolution mapping of GDEs (approximately 30m).
• Analysis of GDE distribution in relation to land use, pastoralism, and groundwater trends.
• Assessment of GDEs within protected areas and regions with sustainable groundwater management policies.

Main Results:

• GDEs are found on over one-third of analyzed global drylands, including biodiversity hotspots.
• GDEs are more extensive in pastoral landscapes with lower groundwater depletion rates.
• 53% of GDEs are in areas with declining groundwater trends, and only 21% are protected.

Conclusions:

• A significant portion of global GDEs are unprotected and threatened by groundwater depletion.
• Mapping GDEs is crucial for developing effective conservation policies and management strategies.
• Integrating socio-economic factors is essential for protecting GDEs, especially in vulnerable regions like the Greater Sahel.