Assisted Migration

Assisted migration” is the human-assisted movement of organisms to new environments. It has been used in forestry and conservation biology to hedge against the effects of climate change. In its simplest form, plants from warmer climates are moved to cooler climates in anticipation of future warming.

The application of assisted migration has stimulated much debate in the scientific community. Detractors adhere to traditional notions that “local is best” and point out the possibilities of failure — and even harm. Proponents point out the risks of extinction and loss of economic value for those species that are unable to adapt to a changing climate without human assistance.

Little of the scientific literature on assisted migration focuses on home landscaping (the focus of the plant sync) — but the attendant controversy may be moot in this sector. Urban and residential landscapes have used plants from outside of their historic range for centuries. This trend is amplified in modern times by a widespread commercial nursery industry and global commerce (See Van der Veken et al., 2008 below). Selection and breeding programs continuously create plant varieties for ornament that are quite different from their native progenitors. Neither of these facts are likely to change within a time window in which climate change action would be effectual, and, broadly speaking, there is no functional reason they should. The question instead is how to manage the diversity of plants in home landscapes to optimize ecosystem services and avoid environmental harm — regardless of genetics or provenance. The provision of ecosystem services by plants in urban and residential environments is not a new idea, but deploying plants in consideration of climate change (e.g. assisted migration) is not a major topic in the ornamental horticulture scientific community, the industry, and the gardening public.

Ornamental plants are chosen for urban and residential landscapes for beauty, shade, wildlife, pollinators, noise reduction, pollution remediation, etc. etc. Shall we make climate change resilience, mitigation, and adaptation a prominent member of this list? And can assisted migration — mindful of risks — play a role?

See also: 

Ode to Provenance

References – Assisted Migration