Establish artificial reserves for at-risk and displaced species

EASTERN:
Species already exist outside their natural habitats in nurseries, arboretums, greenhouses, botanical gardens, and urban environments around the world. These highly controlled environments may be used to support individuals or genetic lineages that are no longer able to survive in their former location, or to serve as interim refugia for rare and endangered plant species that have specialized environmental requirements and low genetic diversity (Fiedler and Laven 1996, Havens et al. 2006, Millar 1991, Vitt et al.2010). These artificial reserves may in some cases maintain species until they can be moved to new suitable habitat. Although a controlled environment would probably require substantial resources, this approach may be critical for at-risk species (Coates and Dixon 2007). (1)

WESTERN:
Species already exist outside their natural habitats in nurseries, arboretums, greenhouses, botanical gardens, and urban environments around the world. These highly controlled environments may be used to support individuals or genetic lineages that are no longer able to survive in their former location, or to serve as interim refugia for rare and endangered plant species that have specialized environmental requirements and low genetic diversity (Millar 1991, Fiedler and Laven 1996, Havens et al. 2006, Vitt et al. 2010). These man-made reserves may in some cases maintain species until they can be moved to new suitable habitat. Although creating and maintaining a controlled environment would probably require substantial resources, this approach may be critical for at-risk species (Coates and Dixon 2007). (2)

Refugia are areas that have resisted ecological changes occurring elsewhere, often providing suitable habitat for relict populations of species that were previously more widespread (Millar et al. 2007, Keppel et al. 2012). Climate refugia are often formed by topography (e.g., north sides of slopes, or sheltered ravines), proximity to large water bodies, or connection to groundwater (Ashcroft 2010, Dobrowski 2011, Morelli et al. 2016, Cartwright 2018, Krosby et al. 2018, Krawchuk et al. 2020, Ebersole et al. 2020, Ackerly et al. 2020). An excellent example of this are the 75 or so giant sequoia (Sequoiadendron giganteum) groves scattered across the Sierra Nevada mountain range that have persisted in sites that are relatively more mesic and have reliable summer moisture (Holland and Keil 1995). Springs and other sites with strong connections to groundwater can provide cool water refugia (Cartwright et al. 2020), and are critical habitat for a variety of California’s threatened and endangered species (Rohde et al. 2019). During previous periods of rapid climate change, at-risk populations persisted in refugia that avoided extreme impacts (Noss 2001, Millar et al. 2007, Keppel et al. 2012, Nydick et al. 2018). These populations allowed species to persist until more favorable climatic conditions returned and species were able to expand into newly available habitats. This strategy seeks to identify and maintain habitats that: 1. are on sites that may be better buffered against climate change and short-term disturbances, and or 2. contain communities and species that are at risk across the greater landscape (Noss 2001, Millar et al. 2007). (2)