title: Andean microrefugia: testing the Holocene to predict the Anthropocene.
abstract: Microrefugia are important for supporting populations during periods of unfavourable climate change and in facilitating rapid migration as conditions ameliorate. With ongoing anthropogenic climate change, microrefugia could have an important conservation value; however, a simple tool has not been developed and tested to predict which settings are microrefugial. We provide a tool based on terrain ruggedness modelling of individual catchments to predict Andean microrefugia. We tested the predictions using nine Holocene Polylepis pollen records. We used the mid-Holocene dry event, a period of peak aridity for the last 100 000 yr, as an analogue climate scenario for the near future. The results suggest that sites with high terrain rugosity have the greatest chance of sustaining mesic conditions under drier-than-modern climates. Fire is a feature of all catchments; however, an increase in fire is only recorded in settings with low rugosity. Owing to rising temperatures and greater precipitation variability, Andean ecosystems are threatened by increasing moisture stress. Our results suggest that high terrain rugosity helps to create more resilient catchments by trapping moisture through orographic rainfall and providing firebreaks that shelter forest from fire. On this basis, conservation policy should target protection and management of catchments with high terrain rugosity.
authors.affiliation: Department of Biological Sciences, Florida Institute of Technology, 150 West University Blvd, Melbourne, FL, 32901, USA.
authors.forename: Bryan G
authors.initials: BG
authors.lastname: Valencia
authors.affiliation: Department of Biological Sciences, Florida Institute of Technology, 150 West University Blvd, Melbourne, FL, 32901, USA. matthewsbirdf@fit.edu.
authors.forename: Frazer
authors.initials: F
authors.lastname: Matthews-Bird
authors.affiliation: Department of Geography, University of Exeter, Amory Building, Rennes Drive, Exeter, EX4 4RJ, UK.
authors.forename: Dunia H
authors.initials: DH
authors.lastname: Urrego
authors.affiliation: Geography & Earth Sciences, Aberystwyth University, Llandinam Building, Penglais Campus, Aberystwyth, SY23 3DB, UK.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Williams
authors.affiliation: Palaeoecology & Landscape Ecology, Institute of Biodiversity & Ecosystem Dynamics (IBED), University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, the Netherlands.
authors.forename: William D
authors.initials: WD
authors.lastname: Gosling
authors.affiliation: Department of Biological Sciences, Florida Institute of Technology, 150 West University Blvd, Melbourne, FL, 32901, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Bush
mesh_terms: D017753:Ecosystem; D065928:Forests; D005843:Geography; D019015:Geologic Sediments / Q000737:chemistry; D010163:Paleontology; D010568:Peru; D013997:Time Factors
keywords: Andes; Polylepis; climate change; conservation; fire; microrefugia; palaeoecology; rugosity