ylivirrankestäjä

The ylivirrankestäjä (*Pseudotsuga menziesii* var. *glauca*), commonly known as the Rocky Mountain Douglas-fir or blue Douglas-fir, is a variant of the Douglas-fir tree native to western North America. It is distinguished by its silvery-blue needles, which give it a unique appearance compared to other Douglas-fir varieties. This variant thrives in mountainous regions, particularly in the Rocky Mountains and the Cascade Range, where it often grows at higher elevations than the more common coastal Douglas-fir (*Pseudotsuga menziesii* var. *menziesii*).

The ylivirrankestäjä typically reaches heights of 40–60 meters (130–200 feet) in mature conditions, though it may be smaller in colder, alpine environments. Its bark is fibrous and scaly, providing some protection against harsh weather. The tree’s cones are small, 3–6 centimeters (1–2.5 inches) long, and hang downward, a characteristic feature of the Douglas-fir genus. Unlike some conifers, the ylivirrankestäjä is not particularly shade-tolerant and prefers full sunlight, though it can adapt to partial shade in its natural habitat.

This variant plays an important ecological role in its range, serving as a habitat for various wildlife species and contributing to soil stability in mountainous terrain. Historically, Indigenous peoples of the region utilized the wood for construction and toolmaking, though it is less commonly used commercially than the coastal Douglas-fir due to its smaller size and slower growth rate. The ylivirrankestäjä is also valued in forestry for its ability to grow in cooler, subalpine climates where other conifers struggle.

Climate change and habitat fragmentation pose challenges to the long-term survival of the ylivirrankestäjä, as rising temperatures and altered precipitation patterns may shift its range upward or reduce suitable growing conditions. Conservation efforts focus on protecting old-growth stands and maintaining forest health to ensure the persistence of this distinctive tree variant.