FOREST MANAGEMENT AND DIVERSIFICATION
UK Eucalyptus silviculture in 2022 Bryan Elliot of Eucalyptus Renewables explains the silvicultural requirements to successfully grow high-yield Eucalyptus species in the UK.
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ucalyptus is suited to Short Rotation Forestry (SRF) as a biomass crop due to producing a high yield at a fast growth rate, typically providing chip or firewood after the fourth year of growth. The wood produced has a high density and produces a very high calorific value. Eucalyptus species typically have a strong apical dominance, meaning that they produce straight stems, perfect for harvesting, handling and transportation, keeping processing costs low using conventional machinery. Many of these Eucalyptus species provenances originate from higher elevations and generally lower average annual temperatures than much of UK. They will thrive given structured silvicultural treatments, which are no different from expected traditional standards of establishment that we should be carrying out for all other trees.
Soil Eucalypts grow well on a range of soils, alkaline as well as acidic and neutral soils within the pH range 4.5 – 7.5, with most species preferring moderately fertile soil types. The vast differences within the Eucalyptus genus’ indigenous habitat have resulted in an inherent adaptability and variation between species to optimal soil type. As a consequence, species such as Eucalyptus dalrympleana (Mountain white gum) and Eucalyptus coccifera (Snow peppermint) can be seen to grow best on rocky dolerite soils, yet more adaptable species such as Eucalyptus glaucescens (Tingiringi gum) will thrive in a wider range of well-drained soil types and pH. Most notable for sites with poor soil quality is Eucalyptus rodwayi (Swamp Peppermint) which has a low site nutrient requirement and an extensive rooting ability
which translates to suitability for land reclamation and shelterbelt qualities.
Eucalyptus and the British climate Eucalypts do not have a true dormant period and retain foliage which enables growth during warm winter periods. As a result the rewards of eucalyptus are yields dramatically higher to those of traditional forestry. Yields will vary greatly depending on the species of Eucalyptus planted, to suit climatic conditions and specific site characteristics. Eucalyptus glaucescens has been successfully established throughout drier East Coast locations, Wales, Midlands and Scotland with annual yields in the region of 25m3/ha/annum. Throughout the southern parts of Britain, Eucalyptus nitens and Eucalyptus denticulata are two similar species that are well suited to temperate climates with
CASE STUDY: Bawtry Plantation, Tiln Farm Estates, Nottingham Bawtry plantation was almost entirely mature single age pines on sandy/ light loam soils. Future Management strategy was based on diversification of age class structure with a varied crop type and productivity objective. As part of this strategy, Compartment 104 was planted with Eucalyptus glaucescens in 2014. Line thinning with some intermediates were felled in 2020, with an estimated 20m3/ha being removed over five hectares. All of the timber was sold locally standing to a firewood merchant with a relatively high return per metre. In 2022 production thinning will again take place with the capacity for higher volumes of removals whilst retaining stand viability. Thinning is important for the crop as light competition reduces tree piece sizes significantly. Complex and evolving silvicultural decisions will be taken in the future to assess maximum yield capacity whilst retaining a thriving deep canopy structure.
50 FORESTRY & TIMBER NEWS • February 2022
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