Brewer Spruce

Can tolerate cold but not fire

This species of spruce, which only occurs in the Klamath and Siskiyou Mountains of southwestern Oregon and northwestern California, was first discovered in 1897 by the American botanist William Henry Brewer. The tree can reach up to 40 m in height and has sloping branches from which many twigs grow vertically downwards – on mature trees they can reach more than 2 m in length.

It grows between 1000 and 2300 m in altitude, particularly on steep, north-facing slopes and ridges where snowfall is high in winter, abundant melt water in the spring, and summer drought. There is still a large handful of known natural sites in the wild on which Brewers weeping spruce is still growing. The species is sensitive to fire due to its thin bark and long, drooping branches.

Especially on steep northern slopes

The particularly striking Pinus breweriana was discovered in 1897 by the American botanist, William Henry Brewer and has a small natural distribution. It can grow to 40 m in height with obliquely pendulous branches from which many smaller branches grow vertically downwards. On a mature tree these branches can reach 2 m in length. The weeping spruce is slow growing, 20 – 30 cm per year, and is popular in gardens because of its weeping habit. The height of cultivated specimens seldom get above 15 m. The wood is of poor quality and not particularly in demand.

Ecology and habitat

Picea breweriana is endemic to the Klamath and Siskiyou Mountains in the far southwest of Oregon and the far northwest of California, not far from the Pacific Ocean. It grows between 1000 and 2300 m above sea level, mainly on steep north facing slopes and ridges where there is high snowfall in winter, lots of thaw water in the spring and summer drought. Under these harsh conditions, faster growing competitors such as the Douglas fir stand little chance. This species thrives in shade and can establish itself successfully under a nearly closed canopy. Seedlings cannot tolerate full sun and they grow very slowly. Because of its shallow roots, the weeping spruce is susceptible to high winds.

Threat

There are a handful of known sites where the weeping spruce grows in the wild and these are under pressure. This species is sensitive to fire because of its thin bark and long pendulous branches. Forest fires are an on going threat, especially through increasing drought as a result of climate change. On the other hand forest fires offer the best chance of regeneration in their natural habitat through the ‘preferential treatment’ of new seedlings, which would otherwise succumb to competition from faster growing conifers.