, 2012 and Milad et al., 2013). This evidence includes reliable science-based estimates of risks and the benefits of management for the mitigation of climate change impacts. Responses based on assisted migration need to include the consideration of all

environmental factors, as the consequences of only partial consideration (response to a single or a few variables only) may be catastrophic (cf. Timbal et al., 2005), with such measures then losing credibility with forest managers. For assisted migration, modelling should consider potential damage by biotic and abiotic disturbances; for example, potential increases in pest and fire risk as a result of stress in the new area (Murdock et al., 2013). Assisted migration responses to climate change that are based on greater dependency on the trans-national exchange selleck inhibitor of forest genetic resources require an appropriate policy and legislative environment to support transfer, including by the harmonisation of phytosanitary requirements, as noted by Koskela et al. (2009).

At a national level, policies defining seed zones will need to be modified to allow the assisted migration of genetic material within nations. Countries developing national forestry action plans should also be encouraged to specifically include genetic level responses to climate change in their plans, which has sometimes, but not always, been the case to date (Hubert and Cottrell, 2007). Designing proper responses to climate change requires a greater understanding of the extent of phenotypic plasticity in trees for important Selleckchem Y27632 Farnesyltransferase traits, the adaptive significance of plasticity, the differences in phenotypic plasticity amongst different genetic levels (genotypes, families, populations, etc.), and the trade-offs between plastic and adaptive responses (Aitken et al., 2008). Also required is further research

on epigenetic effects, especially in angiosperm trees (Rohde and Junttila, 2008). Plastic and adaptive responses can be studied in multi-locational common garden experiments that specifically consider climate-related traits in measurement and design (Rehfeldt et al., 2002 and Vitasse et al., 2010). For animal-pollinated species in particular, research is also needed on the effects of climate change on tree reproductive capacity, such as how elevated temperatures may affect mutualisms with pollinators, and how the changed availability of mutualistic partners influences the persistence of interacting species (Hegland et al., 2009). As in previous climate change episodes, forest genetic resources will recombine to produce new variants, which through natural or assisted selection will produce the genotypes required to continue providing the ecosystem services that societies need from forests. But, as climate change progresses it will be important to monitor the adaptation of trees, stands and ecosystems, and to intervene with efforts to support adaptation where needed.