Forestry England takes part in 25-year Norway spruce provenance planting trial

Forestry England takes part in 25-year Norway spruce provenance planting trial

A provenance trial studying Norway spruce trees growing from seeds sourced from 16 different European locations has got underway in a long-term project to identify trees likely to be resilient to climate conditions 50 years from now. Forestry England, a partner in the Conifer Breeding Co-operative, has recently planted 2,300 trees in Delamere Forest, Cheshire, as part of a total 17,200 trees planted across five sites in England, Scotland and Wales by co-op members.

The trees were grown in Scotland from orchard seeds from Sweden, the Czech Republic, Denmark, Germany and France, and a Forestry England selected-quality seed stand near the Forest of Dean. Used extensively for construction, Norway Spruce produces strong timber with a straight grain and fine texture, as well as being used for paper milling.

The provenance trial will compare trees from the 16 different sources as they grow to identify which have the best overall performance and show the strongest growth and good form. The trees will be monitored at different times over the next 25 years with the first two years assessing survival rates at each site. After that the height, diameter, stem form and density of plants from each of the 16 seed provenances will be compared. Co-op members involved in the trial will do additional assessments on their planting sites after extreme events like flooding, drought, or pest invasions to see how the trees have fared.

Norway spruce was chosen for the trial because it has high drought tolerance compared to Sitka spruce, and can cope with upland acid soils making it ideally suited to a more uncertain future climate in the UK. Some areas where Sitka spruce thrives now are predicted to become too dry for it to be a suitable species as they won’t provide its high demand for soil moisture.

The Conifer Breeding Co-operative has a long-term ambition to develop an improved domestic population of Norway spruce to meet national demand and is working to a 30-year timescale carrying out selection and testing. This 25-year Norway spruce provenance trial is running alongside as an interim project to see which existing widely available European orchard and UK select seed sources are the best to grow before the domestic improved seed becomes available.

Nicola Rivett, Forestry England Seed Resource Manager spokesperson said:

“Being able to compare Norway spruce trees growing from such a diverse range of seed sources in this provenance trial will give valuable information about which seed is genetically best suited for future soil and climate conditions, and help Forestry England and partner organisations focus seed and plant supply on those varieties. We’re working long-term on this, and it will be 2046before the trees we’ve all planted this spring reach maturity. But the information they give us along the way will be crucial in helping steer the right course in adapting and planning our future Norway spruce growth and supply.”

As well as focusing on Norway spruce, The Conifer Breeding Co-operative is also looking at Douglas fir, Sitka spruce, Scots pine and hybrid spruce, identifying the best genetic planting material, and selecting trees growing in good quality stands to create new seed orchards for future planting stock.

Visitors to Forestry England’s planting site in Delamere Forest will have the chance to see the trial progress over the coming years as the trees mature.