Context

Drought occurrence and severity are expected to increase in large parts of Britain as a consequence of climate change. Sitka spruce (Picea sitchensis), which accounts for 60% of UK timber production, originates from the oceanic north west of America and is not adapted to drought conditions. Evidence from central Europe shows that drought is a major driver of pest outbreaks that have devastated large areas of native Norway spruce (Picea abies).

Additionally, drought is suspected to be a factor in internal wood failure, which greatly reduces the value of the timber produced. Given this context, the resilience of spruce forests needs to be enhanced in Britain in order to secure the provision of high-quality timber to industry. This is a major objective of the Forestry Commission and one of the key elements of the UK Net Zero Strategy.

Research aims and objectives

Aim

To identify a series of heritable traits for drought tolerance in the Sitka spruce breeding population, which can be used to select for more resilient trees.

Objectives:

• Study the genetic control of relevant resilience traits – different traits known to be associated with resilience to drought will be extracted from wood samples from a number of different cloned genetic families from Forest Research’s clone banks to assess their heritability. These traits will also be calculated in the original clones to determine evaluation of the full breeding population from clone banks is possible.
• Test proxies such as wood density and drought cracks, that can be used as markers of the existence of the above traits. These proxies will also be tested in clone banks.
• Economically quantify the benefits of including drought tolerance in the breeding criteria against the current system.

Expected outcomes

• A trade article on heritability estimates for resilience traits.
• Report on resilience proxies.
• New criteria in index selection (if applicable).
• Submission of manuscript aimed at a scientific publication on the economic quantification of considering drought tolerance as a breeding criterium.