Picea sitchensis Sitka Spruce

Sitka Spruce is the most important timber tree in Britain and Ireland and simply in terms of the number of individuals growing here, it is our most common tree. It is native to the fog-belt, coastal forests of the Pacific Northwest from northern California to Alaska and grows to produce massive trees in the 'old growth' forests of that region. Giant Sitka Spruce trees are found on some of the islands off British Columbia and along the Olympic peninsula in Washington. It forms the subalpine timberline in the mountains of southern Alaska. It was first introduced to Britain in 1831 where it is now planted on about one third of the area of forest land. Most of the Sitka Spruce in West Glamorgan is in the Neath and Afan Valleys where it was first planted in large amounts in the second half of the 20th Century. Sitka Spruce grows exceedingly well in the mild, wet climate of south Wales where it is cultivated in monoculture coupes for up to 60 years before harvest. Like many other conifers, Sitka Spruce will not coppice but exposed trees, after thinning or clearfell, often produce large amounts of epicormic sprouts on their trunks. Older trees produce copious amounts of seed in cones that hang down from the higher branches and the seed rain that results from this gives rise to significant amount of regeneration in non-forest areas of plantations, e.g. in dwarf shrub heath, roadside banks and verges and quarries. This poses a significant problem for the conservation and management of biodiverse habitats and communities in those habitats. Large amounts of Sitka Spruce have also been planted on areas of undrelying deep peat which has led to significant drying of these important carbon sequestration sinks. The Sitka Spruce forests in our plantations do not support a diverse vascular plant flora, but some have bryophyte floras that resemble those of upland Sessile-oak woodland. The diverity of macrofungal fruiting bodies is often significant however and mature coupes are important habitats for birds such as Siskin, Lesser Redpoll and Crossbill.

Planted extensively but frequently regenerates and naturalises as a neophyte.