Sourcing seed for restoration in an era of climate change: conceptual frameworks and available evidence

Rapid climate change has prompted concerns that seed sourced from plant populations near restoration sites will be poorly adapted to future climate conditions and will fail to adapt as conditions change. As a result, some researchers and practitioners advocate for actively translocating non-local genetic material with the intention of enhancing pre-adaptation of restored populations to future climate (i.e., “assisted migration”). However, the paucity of direct experimental evidence that such “predictively” sourced seed outperforms seed from locally sourced populations as the climate changes undermines confidence in this approach. In contrast, a large body of research has shown that evolutionary adaptation can be rapid, and recent experiments demonstrate that populations—including highly fragmented ones—retain capacity for ongoing adaptation. Thus, available experimental evidence supports sourcing seeds from populations near restoration sites as a key component of a proactive strategy to establish resilient and well adapted plant populations.