Yellow tree leaves

Provenance and therefore genetic diversity, in addition to species diversity, is important in the context of climate change, especially in the fight against the increasing threat from pests and pathogens.

The role of natural selection

The natural variation within a species is a source of resilience that could be used by foresters to reduce the risk of crop failure.

New pests and diseases will present new challenges and through the process of natural selection, individuals with certain variants of genes or gene combinations will be favoured if they confer resistance. Consequently these will be the individuals that survive the challenge and produce the next generation.

The importance of seed source

Correct choice of seed source will be an important part of adaptation to climate change given that trees planted in this decade may well experience the climate of latitudes two to three degrees further south by the time they reach maturity.

Diversity in native and semi-natural woodlands

Evidence suggests that most populations of trees in semi-natural woodlands contain high levels of genetic diversity. Linking and expanding native woods using natural regeneration as part of a habitat network, or planting with well-adapted stock, will increase gene flows and strengthen the capacity of tree populations to adapt.

This increased interest and understanding of the importance of genetic diversity has been reflected within the UK Forestry Strategy and other policy documents.

Further information

We have produced a forest resilience Good Practice Guide on managing the genetic diversity of Welsh woodlands.

Natural Resources Wales is continuing to support research that will help us provide more information.

If you would like to contact the Sustainable Forest Management Team in Natural Resources Wales you can send your enquiry to

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