title: Seed supply for broadscale restoration: maximizing evolutionary potential.
abstract: Restoring degraded land to combat environmental degradation requires the collection of vast quantities of germplasm (seed). Sourcing this material raises questions related to provenance selection, seed quality and harvest sustainability. Restoration guidelines strongly recommend using local sources to maximize local adaptation and prevent outbreeding depression, but in highly modified landscapes this restricts collection to small remnants where limited, poor quality seed is available, and where harvesting impacts may be high. We review three principles guiding the sourcing of restoration germplasm: (i) the appropriateness of using 'local' seed, (ii) sample sizes and population characteristics required to capture sufficient genetic diversity to establish self-sustaining populations and (iii) the impact of over-harvesting source populations. We review these topics by examining current collection guidelines and the evidence supporting these, then we consider if the guidelines can be improved and the consequences of not doing so. We find that the emphasis on local seed sourcing will, in many cases, lead to poor restoration outcomes, particularly at broad geographic scales. We suggest that seed sourcing should concentrate less on local collection and more on capturing high quality and genetically diverse seed to maximize the adaptive potential of restoration efforts to current and future environmental change.
authors.affiliation: CSIRO Plant Industry Canberra, ACT, Australia.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Broadhurst
authors.affiliation: Ecology & Evolutionary Biology, The University of Adelaide Adelaide, SA, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lowe
authors.affiliation: Department of Environment and Conservation, Bentley Delivery Centre WA, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Coates
authors.affiliation: CSIRO Entomology Canberra, ACT, Australia.
authors.forename: Saul A
authors.initials: SA
authors.lastname: Cunningham
authors.affiliation: CSIRO Centre for Environment and Life Sciences Wembley, WA, Australia.
authors.forename: Maurice
authors.initials: M
authors.lastname: McDonald
authors.affiliation: School of Botany, The University of Melbourne Parkerville, VIC, Australia.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Vesk
authors.affiliation: Department of Environment and Conservation, Bentley Delivery Centre WA, Australia.
authors.forename: Colin
authors.initials: C
authors.lastname: Yates
keywords: evolutionary potential; genetic diversity; germplasm; provenance; restoration; seed quality