Climate-adjusted provenancing: a strategy for climate-resilient ecological restoration

Investments in ecological restoration are estimated at $US 2 trillion per annum worldwide and are increasing rapidly ( Cunningham, 2008 ; Williams et al., 2014 ). These investments are occurring in an environment of accelerated climate change that is projected to continue into the next century, yet they currently take little account of such change. This has significant implications for the long-term success of restoration plantings across millions of hectares, with germplasm used in current restoration efforts potentially poorly-adapted to future climates. New approaches that optimize the climate-resilience of these restoration efforts are thus essential ( Breed et al., 2013 ; Williams et al., 2014 ; Havens et al., 2015 ). A promising, but as yet untapped, opportunity for enhancing the climate-resilience of restoration investments rests in the exploitation of natural genetic variability of plant species. The capacity of plants to adapt to environmental change through plasticity, selection, or gene flow is only beginning to be explored ( Nicotra et al., 2010 ; Hoffmann and Sgro, 2011 ; Aitken and Whitlock, 2013 ; Alberto et al., 2013 ). Informed strategies for sourcing germplasm that capitalize on inherent genetic diversity and adaptive capacity offer significant promise for improving the success of extensive plantings to restore landscapes that are eroded, salinized, desertified, highly fragmented or degraded through introduced competitors, herbivores, or diseases. Here we describe a new strategy for sourcing germplasm for ecological restoration to promote adaptation in a changing climate. We argue that a "climate-adjusted" provenancing strategy (Figure 1A ) should combine genetic diversity and adaptability, targeting projected climate change directions whilst allowing for uncertainty in such projections as well as unforeseen selective agents. We introduce climate-adjusted provenancing in the context of historical approaches to provenancing, and highlight emerging research to test this strategy.