Douglas fir Douglas-fir forest is the primary habitat of the red tree vole ("Arborimus longicaudus") and the spotted owl ("Strix occidentalis"). Home range requirements for breeding pairs of spotted owls are at least 400 ha () of old growth. Red tree voles may also be found in immature forests if Douglas-fir is a significant component. The red vole nests almost exclusively in the foliage of the trees, typically above the ground, and its diet consists chiefly of Douglas-fir needles. A parasitic plant sometimes utilizing "P. menziesii" is Douglas-fir dwarf mistletoe ("Arceuthobium douglasii"). The leaves are also used by the woolly conifer aphid
Douglas Ranges Douglas Ranges The Douglas Ranges are a subrange of the Pacific Ranges of the Coast Mountains of the Canadian province of British Columbia, about east of downtown Vancouver, north of the Fraser River and between the valleys of Stave and Harrison Lakes. They are approximately in area. Their highest peak is Mount Robertson , at the northwest limit of the range. The Douglas Ranges among the smallest and lowest of the major named subranges Coast Mountains, but in addition to being smallest and lowest they are also the southernmost part of the Coast Mountains and therefore also of the Pacific