Pseudotsuga macrocarpa (Vasey) Mayr

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Pseudotsuga macrocarpa, commonly called the bigcone spruce or bigcone Douglas-fir, is an evergreen conifer native to the mountains of southern California. It is notable for having the largest (by far) cones in the genus Pseudotsuga, hence the name.

The tree occurs from the San Rafael Mountains in central Santa Barbara County and the Tehachapi Mountains of southwestern Kern County, south through the Transverse Ranges, to the Cuyamaca Mountains in San Diego County. The tree is shade-tolerant and prefers to grow on slopes.

Name

Pseudotsuga macrocarpa is a Douglas-fir. The name "bigcone spruce", though confusing as it is not a spruce species, is often still used, and occurs in place names.

Description

Pseudotsuga macrocarpa typically grows from 15–30 m (49–98 ft) in height and 56–155 cm (1 ft 10 in – 5 ft 1 in) in trunk diameter. The growth form is straight, with a conical crown from 12–30 m (39–98 ft) broad, and a strong and spreading root system. The bark is deeply ridged, composed of thin, woodlike plates separating heavy layers of cork; bark of trees over 1 m (3.3 ft) in diameter is from 15–20 cm (5.9–7.9 in) thick. The main branches are long and spreading with pendulous side shoots.

The leaves are needle-like, 2.5–4.5 cm (0.98–1.77 in) long, are shed when about 5 years old. The female cones are from 11–17 cm (4.3–6.7 in) long, larger and with thicker scales than those of other douglas-firs, and with exserted tridentine bracts. The seeds are large and heavy, 10 mm long and 8 mm broad, with a short rounded wing 13 mm long; they may be bird or mammal dispersed as the wing is too small to be effective for wind dispersal. Trees start producing seeds at about 20 years of age.

The largest known individual of this species is 53 m (174 ft) tall, 231 cm (91 in) in diameter, and is estimated to be from 600 to 700 years of age.

Distribution

Pseudotsuga macrocarpa is restricted to the California montane chaparral and woodlands and California coastal sage and chaparral ecoregions of California.

 

It prefers a Mediterranean climate, characterized by hot dry summers and wet, mild winters. Annual rainfall during a 30-year period on a bigcone Douglas-fir site in the San Gabriel Mountains averaged 75 cm (30 in) and ranged from 25–125 cm (9.8–49.2 in).

Bigcone Douglas-fir occurs between 300–2,700 m (980–8,860 ft). At low elevation, it occurs near streams in moist, shaded canyons and draws where aspects are mostly north and east. At elevations from 1,350–1,700 m (4,430–5,580 ft), aspects include south- and east-facing slopes. At these elevations, it also grows on sloping hillsides, ridges, and benches. At higher elevations, it occurs on south and west aspects on all types of terrain. The average angle of slope on which it grows is 35 degrees, ranging from level to 90 degrees, although these extremes are uncommon.

Ranges the tree is found in, south to north, include:

Pseudotsuga macrocarpa - Wikipedia

https://youtu.be/X94uKLxNke0

 

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