The role of true fir species in the silviculture of British forests: past, present and future.
There are no true fir species (Abies spp.) native to the British Isles: the first to be introduced was Abies alba in the 1600s which was planted on some scale until the late 1800s when it proved vulnerable to an insect pest. Thereafter interest switched to North American species, particularly grand (Abies grandis) and noble (Abies procera) firs. Provenance tests were established for A. alba, A. amabilis, A. grandis, and A. procera. Other silver fir species were trialled in forest plots with varying success. Although species such as grand fir have proved highly productive on favourable sites, their initial slow growth on new planting sites and limited tolerance of the moist nutrient-poor soils characteristic of upland Britain restricted their use in the afforestation programmes of the last century. As a consequence, in 2010, there were about 8000 ha of Abies species in Britain, comprising less than one per cent of the forest area. Recent species trials have confirmed that best growth is on mineral soils and that, in open ground conditions, establishment takes longer than for other conifers. However, changes in forest policies increasingly favour the use of Continuous Cover Forestry and the shade tolerant nature of many fir species makes them candidates for use with selection or shelterwood silvicultural systems. Supporting evidence is provided by analysis of the regeneration in a long term study of transformation of first rotation conifer plantations. The need to adapt forests to climate change has identified some other silver fir species from southern Europe and Asia as having potential to help increase the resilience of British forests against the impacts of a warmer climate. This paper is the first review of experiments, operational experience with, and the potential role of silver firs in British forestry for more than 20 years. It suggests that previous reviews of the potential role of Abies species have been unduly pessimistic and that there should be an expanded place for silver fir species in British forestry in the future.