Andean microrefugia: testing the Holocene to predict the Anthropocene.

Area of Science:

• Ecology
• Climate Change Biology
• Geomorphology

Background:

• Microrefugia are critical for species survival during climate shifts and aid post-disturbance recolonization.
• Anthropogenic climate change increases the need for effective microrefugia identification tools for conservation.
• Predicting microrefugial sites is challenging, lacking simple, tested methodologies.

Purpose of the Study:

• To develop and validate a simple tool for predicting microrefugia in Andean catchments.
• To assess the role of terrain ruggedness in maintaining mesic conditions under arid scenarios.
• To inform conservation strategies for Andean ecosystems facing climate-induced moisture stress.

Main Methods:

• Terrain ruggedness modelling applied to individual catchments to predict potential microrefugia.
• Validation of model predictions using nine Holocene Polylepis pollen records.
• Utilizing the mid-Holocene dry event as a paleoclimate analogue for future arid conditions.

Main Results:

• High terrain rugosity sites demonstrate a greater capacity to sustain mesic conditions during drier periods.
• Low rugosity areas exhibited increased fire incidence, while high rugosity areas showed firebreak effects.
• Catchments with high terrain rugosity are more resilient due to moisture trapping and fire protection.

Conclusions:

• Terrain ruggedness is a key predictor of microrefugia in the Andes.
• Conservation efforts should prioritize the protection and management of high terrain ruggedness catchments.
• These findings offer a practical approach to enhance Andean ecosystem resilience against climate change.