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Owen Lewis

Tom Sim

Macedonian pine (MCP)

Macedonian pine is a five-needled pine native to the Balkan peninsula. Little planted as a forest species but it has demonstrated potential as hardy, healthy specimens in botanic collections across Britain. Limited trials in Britain have indicated its productive potential and its apparent resistance to several of the diseases affecting pines. This could mean an increase in importance with climate change, not least if other pine species are further affected by disease. Macedonian pine is listed as near threatened by the IUCN. Macedonian pine is categorised as a plot-stage species. These are species that have demonstrated some positive silvicultural characteristics at the Specimen-stage and are now subject to further testing and development in a limited number of trial plots.

Leyland cypress (LEC)

Leyland cypress is a hybrid between Cupressus macrocarpa and Cupressus nootkatensis. It is believed to have originated at Leighton Hall, Welshpool, from cones collected in 1888. There are many clones which have been widely used in horticulture and garden settings. The timber is naturally durable and valuable, but its stem form makes utilisation very difficult. For this reason, Leyland cypress has historically had little place in British forestry.  It is being planted on a limited scale for forest diversification and has survived and grown well on a wide range of sites. Future use of this tree could expand if climate warming progresses as predicted, particularly in western Britain and elsewhere with adequate soil moisture. Leyland cypress is categorised as a Secondary tree species. These are species that have demonstrated positive silvicultural characteristics in trial plots but gaps in knowledge constrain wider use. The species are being actively evaluated to increase understanding and inform future deployment.

Lawson cypress (LC)

Lawson cypress (also known as Port Orford cedar) was introduced in 1854 by William Murray. Its common name derives from the plantsman Lawson who first grew it in Edinburgh. It has been trialled as plots and small plantations throughout Britain, but it is better known as a landscape tree. Lawson cypress naturally produces variable forms widely adopted for horticultural use. There is growing interest in the use of Lawson cypress in forest diversification particularly in underplanting. Wild populations have been affected by the pathogen Phytophthora lateralis and is now listed as near threatened by the IUCN. Lawson cypress is categorised as a secondary tree species. These are tree species that have demonstrated positive silvicultural characteristics in trial plots but gaps in knowledge constrain wider use. The species is undergoing active evaluation to increase understanding and inform future deployment.

Japanese red-cedar (JCR)

Japanese red-cedar is a long-lived species that grows into a large tree – records of 65 m – with straight character and moderately-strong scented wood. Tolerant of a wide range of sites and climates and has been extensively planted in Japan and elsewhere. Although not widely planted in Britain it is increasing in usage as a species for forest diversification. Japanese red-cedar is categorised as a secondary tree species. These are tree species that have demonstrated positive silvicultural characteristics in trial plots but gaps in knowledge constrain wider use. The species are being actively evaluated to increase understanding and inform future deployment.

Grand fir (GF)

A non-native, under-utilized species that has potential as a productive forest tree for forest diversification. It cannot tolerate exposure as well as noble fir, but is quicker to establish, and subsequent growth is rapid.  Its timber is perceived to be poor, but only limited testing has taken place in Britain. Grand fir is categorised as a Principal tree species. These are tree species where silvicultural knowledge provides confidence to enable successful deployment across Britain. The species are either already widely used or are increasing in usage.  They will continue to be important unless affected by a new pest or disease or become adversely affected by climate change.

European silver fir (ESF)

European silver fir is a long-lived conifer and the largest tree (up to 60 m) of the native Abies in Europe. It is not native to Britain but was an early introduction in 1603. Although widely planted as a specimen tree it has only been used on a small scale as a forestry species. Poor uptake was because early trials indicated susceptibility to silver fir wooly aphid; however, a recent reassessment of the species indicated it can be a productive species in Britain. There is growing recognition it has a place in forest diversification and is consequently being more widely used. European silver fir is categorised as a Secondary tree species. These are a group that have demonstrated positive silvicultural characteristics in trial plots but gaps in knowledge constrain wider use. The species are being actively evaluated to increase understanding and inform future deployment.

Coast redwood (RSQ)

Coast redwood is the world’s tallest tree and can regularly top 110 m in suitable conditions. It is growing in popularity particularly as a species for under planting. Fine stands can be found across Britain with one example at Leighton in Powys said to have achieved the highest standing volume of any plantation in Britain. This is a species that could be grown more widely in Britain with climate warming, not least because it grows quickly and produces a high-quality timber. Coast redwood is listed as Endangered by the IUCN. Coast redwood is categorised as a secondary tree species. These are species that have demonstrated positive silvicultural characteristics in trial plots but gaps in knowledge constrain wider use. The species are being actively evaluated to increase understanding and inform future deployment.

Common (or black) alder (CAR)

Common alder is a short-lived fast-growing tree that grows naturally throughout Britain. It thrives in the wetter areas of the north and west but grows wherever there is ample year-round water. Wet woodlands dominated by common alder are also known as ‘alder-carr.’ Although coppiced in the past for turnery and charcoal – the preferred charcoal for gunpowder production – common alder does not presently have a significant role in productive forestry but is commonly planted as part of establishing native woodlands. A warming climate and changes in water availability may see its northerly range extend and contract in the south. Common alder is native to Britain and considered a Principal tree species. These are species where silvicultural knowledge provides confidence to enable successful deployment across Britain. The species are either already widely used or are increasing in usage. They will continue to be important unless affected by a new pest or disease or become adversely affected by climate change.

Cider gum (EGU)

Cider gum was introduced into Britain over 150 years ago and is now a common ornamental often dominating small gardens in urban areas. It has been widely trialled and a number of forest plots survive in lowland and coastal areas of Britain. Probably the safest eucalypt species to plant in Britain at the present time and the potential range is likely to expand with climate warming. One of the hardiest eucalypts along with the snow gums (E. pauciflora spp.) but has been little planted despite demonstrating potential for high productivity. Like all eucalypts there is no resting bud so cold tolerance relies on hardening-off in the autumn and this leaves them vulnerable to unseasonal frosts and occasional severe winters. Cider gum is categorised as a secondary tree species.  These are species that have demonstrated positive silvicultural characteristics in trial plots but gaps in knowledge constrain wider use. The species are being actively evaluated to increase understanding and inform future deployment.

Cedar-of-Lebanon (LCR)

This Mediterranean cedar has long been valued for its fine timber and impressive stature and has been used from antiquity. While natural stands are now very fragmented, it is increasingly planted in Turkey and in many trials elsewhere including in the UK where its performance is being assessed. Earliest known introduction to Britain is 1638, and the original tree near Wantage is still thriving indicating long life and tolerance of conditions as do the numerous ornamental specimens in parks and gardens, many dating back to the 18th Century. In the UK, cedar-of-Lebanon has the potential for wider use as the climate warms. It could become a valuable addition to the suite of species for lowland planting in southern Britain, particularly where soils are neutral to calcareous. Cedar-of -Lebanon is listed as Vulnerable by the IUCN. Cedar-of-Lebanon is categorised as a plot-stage species. These are a group of species that have demonstrated some positive silvicultural characteristics at the Specimen-stage and are now subject to further testing and development in a limited number of trial plots.