Trial species

Choosing the right species for biomass is about balancing two key factors - fast early growth and high wood density i.e. greater biomass per unit volume.

Fastgrowing willow (Salix spp) is considered the most appropriate Short Rotation Coppice (SRC) choice but there is a wider range of potentially useful Short Rotation Forestry (SRF) species, both native and exotic, that combine fast growth and high density.

Comparison of wood properties and potential yield of SRF and SRC species.
SpeciesAir-dried density (kg/m3 @ 12% MC)Calorific value (GJ/m3)GYCRotation (years)Yield over 50 years (Dry T/ha)
Eucalyptus gunnii 700 12.5 24+ 10 750
Ash 689 12.4 8 20 370
Silver birch 673 12.1 6 20 250
Sycamore 561 10.1 8 20 350
Common alder 513 9.2 10 15 250
Japanese larch 481 9.1 10 20 210
Aspen (native) 480 8.6 12 15 280
Nothofagus 465 8.4 18 15 590
Sitka spruce 384 7.3 16 20 360
Willow (SRC) 430 7.7 n/a 3 400

 

eucalyptus

To maximise site productivity as early as possible, all intensive trial SRF species will be planted at 2 x 1 metres (5,000 trees/ha), with the option to thin later if this will improve the yield.

The optimum rotation length will depend upon species' growth rates and
will be a balance between maximising yield and the economics of utilisation, however, it is expected to be somewhere between 10 - 20 years in Scotland.

Interim guidance on the grant aiding and planting of Eucalyptus in Scotland

This interim guidance briefly examines the various issues around Eucalyptus in a Scottish context and provides recommendations for its use: Interim Eucalyptus Guidance (PDF 1.2Mb)