Elm in the Highlands: Current status and potential management responses to Dutch elm disease (Ongoing)

Euan Bowditch & Elspeth Macdonald (Collaboration with Forestry Commission Scotland)

Deformed tree trunk

This project examined the current population of elm species in Scotland, focussed on the Highlands and Islands, examining their distribution, structure and condition.  Additionally economic, landscape and cultural value is assessed to inform the wider importance of the species to the region.  From the analysis of both species distribution and spread of Dutch elm disease management responses and planting strategies have been formulated to create a regionally specific management plan for restoration of the species and management of DED.

Walking the land: Examining an ecosystem approach for private estates through the lens of woodland expansion (2016)

Euan Bowditch (PhD Thesis)

This project presents a local interpretation of an ecosystem approach; ‘energyscapes’ constructed through mixed methods, which captures private estate manager perception on land use, woodland expansion and collaboration over four case study areas in the Scottish Highlands.  Each case study area of three contiguous estates forms a small landscape cluster, with every estate participating in field interviews, woodland planning and collaborative discussions.  Private estates in Scotland cover a significant area of the Highlands and are dominated by traditional sporting interests and recreation that is not always considered compatible with woodland expansion, creating a culture of woodland neglect.  Subsequently planting rates are falling and Scottish government woodland expansion targets are not being met, despite large areas of vacant land.

Key areas of estate and woodland resilience are identified by land managers to improve social and structural connectivity using the novel landscape resilience mapping method, which presents land manager perceptions over a spatial scale linked to resilience concepts.  The Forest Energy Tool developed in response to the need for economic justification for woodland expansion demonstrates the potential profitability of local woodfuel markets, as well as providing silvicultural treatments for further management aims.  Estate resilience involves fostering effective integration between sporting uses, renewable energy and enhanced rural markets, such as value added forestry.

Ecosystem approaches are normally expressed through aspirational policy that is difficult to translate into relevant practice for individual land managers.  Energyscapes provides meaning to ecosystem approach policy through CBD principles and operational guidelines, and local practice; including integration of hydro schemes, forest energy and carbon sequestration at estate level and bridging of local and regional scales through six land manager identified landscape partnerships.  However, developing leadership, as well as expertise and social capacity in landscape management, is required to mobilise such frameworks.  Fundamental to realising these local ecosystem approaches is land manager trust and confidence, which can generate support for emerging land uses alongside tradition, increasing resilience by capturing and utilising the culture embedded within the landscape.

Improving the mechanical properties and performance of Sitka spruce timber through selection and breeding (current)

Elspeth Macdonald (part-time PhD project), in collaboration with Forest Research and the University of Aberdeen

Sitka spruce is the main commercial conifer species grown in Britain, accounting for 60% of total softwood timber production. A 50-year programme of selection and breeding has focused on improving growth rate and stem form while maintaining wood density. There has been little work to date on breeding to improve wood stiffness, a critical property in the mechanical performance of construction timber. This study aims to determine whether selective breeding can improve the mechanical properties of Sitka spruce by first calculating the heritabilities of key wood traits using non-destructive techniques, then correlating these values with direct measurements made through destructive sampling.

Two progeny trials planted in 1985, at Spadeadam in northern England and at Radnor in Wales, were selected for this study. Each trial contains 61 full-sibling families derived from controlled pollination between selected Sitka spruce plus-trees, plus unimproved controls. Measurements of tree growth (diameter at breast height), wood density (assessed indirectly by Pilodyn pin penetration) and wood stiffness (assessed indirectly using acoustic velocity) were made on all live trees in both trials. A sub-sample of 30 families were selected for destructive analysis and 10 trees in each family were felled to obtain sample material for assessment of physical and mechanical properties: clearwood stiffness and strength, earlywood and latewood width, wood density, grain angle and cell wall thickness. Correlations between indirect assessments of stiffness and density and the destructive measurements made in the laboratory are being investigated, together with correlations between and among the wood properties measured and their genetic parameters.

Extraction of sample logs at Spadeadam forest

extraction of sample logs at Spadeadam forest

Measuring grain angle at Spadeadam forest

measuring grain angle at Spadeadam forest

Bending test on wood sample at Forest Research

bending test on wood sample at Forest Research

Cutting sample logs at SSF

Cutting sample logs at SSF