A landscape-scale framework to identify refugia from multiple stressors

Area of Science:

• Ecology
• Conservation Biology
• Environmental Science

Background:

• Climate refugia are critical for species persistence, but other anthropogenic stressors like altered fire and hydrology regimes also threaten habitats.
• Conservation efforts focused solely on climate may be undermined by unaddressed human-induced habitat loss, degradation, and fragmentation.
• Advances in quantifying refugial capacity across multiple stressors are vital for effective conservation planning.

Purpose of the Study:

• To introduce a novel conceptual framework, the domains of refugia, for assessing conservation refugial capacity by identifying areas with low exposure to multiple anthropogenic stressors.
• To apply this framework to a Southern California landscape to identify and evaluate potential super-refugia sites.
• To inform conservation strategies and protected area network expansion by highlighting underrepresented refugial areas.

Main Methods:

• Developed the domains of refugia conceptual approach, integrating environmental variability, resilience thresholds, and stressor extent/intensity.
• Applied the framework to a Southern California landscape, assessing exposure to stressors including extreme temperatures, fire, altered hydrology, and recreational trails.
• Quantified differences in stressor exposure between identified super-refugia sites and the surrounding landscape.

Main Results:

• Identified super-refugia sites characterized by significantly lower exposure to extremely warm summers (30% less), fire events (20% less), altered river channels/riparian areas (10% less), and recreational trails (50% less).
• Approximately 8200 km² of potential super-refugia sites were identified for certain natural communities within the study area.
• These identified super-refugia sites are currently underrepresented in the existing protected area network.

Conclusions:

• The domains of refugia framework provides a robust method for assessing conservation potential across multiple anthropogenic stressors.
• Integrating multiple stressors into refugia identification is essential for comprehensive biodiversity conservation planning.
• Findings underscore the need to expand protected areas to encompass identified super-refugia sites to enhance long-term biodiversity persistence.