title: Fine-grain modeling of species' response to climate change: holdouts, stepping-stones, and microrefugia.
abstract: Microclimates have played a critical role in past species range shifts, suggesting that they could be important in biological response to future change. Terms are needed to discuss these future effects. We propose that populations occupying microclimates be referred to as holdouts, stepping stones and microrefugia. A holdout is a population that persists in a microclimate for a limited period of time under deteriorating climatic conditions. Stepping stones successively occupy microclimates in a way that facilitates species' range shifts. Microrefugia refer to populations that persist in microclimates through a period of unfavorable climate. Because climate projections show that return to present climate is highly unlikely, conservation strategies need to be built around holdouts and stepping stones, rather than low-probability microrefugia.
authors.affiliation: Betty and Gordon Moore Center for Science and Oceans, Conservation International, Arlington, VA, USA. Electronic address: lhannah@conservation.org.
authors.forename: Lee
authors.initials: L
authors.lastname: Hannah
authors.affiliation: United States Geological Survey, Sacramento, CA, USA.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Flint
authors.affiliation: Conservation Biology Institute, La Mesa, CA, USA.
authors.forename: Alexandra D
authors.initials: AD
authors.lastname: Syphard
authors.affiliation: Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA.
authors.forename: Max A
authors.initials: MA
authors.lastname: Moritz
authors.affiliation: Department of Biology, University of Washington, Seattle, WA, USA.
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Buckley
authors.affiliation: Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA, USA.
authors.forename: Ian M
authors.initials: IM
authors.lastname: McCullough
mesh_terms: D063147:Animal Distribution; D057231:Climate Change; D003247:Conservation of Natural Resources; D008834:Microclimate; D063148:Plant Dispersal
keywords: climate change; conservation; holdout; microrefugia; range shift; stepping-stone