Sep 30, 2009

Sitka spruce - picea sitchensis

The Sitka Spruce is named after a place called Sitka in Alaska although its natural range is all along the coast of NW America. It was introduced to Britain in 1831 and is therefore a non native conifer. The tree grows with a very straight conical shape trunk. Long downward flowing branches hang down low from the pointed crown.

It can grow up to 50 m or more with a trunk over 2m in diameter.

Is greyish brown which gets curved fissures and flaky plates as it grows.

Leaves Flowers and Cones

Leaves are green flattened needles that grow individually. They are stiff, hard and very sharp. The red flositka flowerswers are seldom seen as they are found right at the top of the older trees. They ripen into pale brown, blunt and domed cones. The thin, hard, crinkled scales of the cones protect the seeds inside.

Where and how does the Sitka Spruce grow?

This conifer naturally grows on the west coast of North America . It has a very fast growth rate compared to some other trees. This means it can yield high volumes of timber in a comparatively short time. Foresters have developed models for growth or yield. The “yield class” figure is the mean cubic metres growth, for each hectare of tree species for each years growth. Sitka spruce has a yield class of 14 (14 cubic metres per hectare per year); Oak can be as low as 4. In terms of time, a Sitka spruce only needs to grow for 40 -60 years to reach its maximum timber potential. An oak can take up to and over 150 years.

The Sitka Spruce has been grown commercially for timber especially in upland locations. Deep, moist and well drained soils are best for growth and so it flourishes in the North and West of the country on damper and elevated sites. Seeds dropped naturally from this conifer grow extremely well and at enormous rates; this “natural regeneration” is encouraged in many Forest sites.

Wildlife around the Sitka Spruce

Sitka Spruce can grow close together to make a very dense canopy. It is difficult for sunlight to find it’s way through to the woodland floor so few plants can grow underneath them. Sitka Spruce do, however, give excellent shelter from wind, rain, cold and sometimes the heat of the sun. Larger animals such as deer and foxes like to find cover amongst the branches. Birds of prey, like Goshawks and Sparrowhawks can find excellent nesting and hunting sites on and around the Sitka Spruce.

Smaller birds such as the Crossbill, Tree Creeper, Coal tit and Siskin also enjoy living and feeding around the Sitka Spruce. picture


The wood from this tree is top quality - it is very versatile and is easy to work with. “Thinnings” (smaller trees taken from plantation) are particularly valuable for paper making as the white colour of the wood and long cellulose fibres make strong but smooth paper

Sitka spruce wood today

Boat and ship construction, pallets, packing boxes, board manufacture and paper making
Old uses - Used for aircraft frames and gliders.

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