* Forests can also be classified more specifically based on the climate and the dominant tree species present, resulting in numerous different forest types ( e. g., ponderosa pine / Douglas-fir forest ).

The Old Norse name is still used for pines in some modern north European languages, in Danish, fyr, in Norwegian fura / fure / furu, Swedish, fura / furu, and Föhre in German, but in modern English, fir is now restricted to Fir ( Abies ) and Douglas-fir ( Pseudotsuga ).

In spring and winter ( in British Columbia, Idaho, and Montana ) elk browse on south-and southwest-facing Rocky Mountain Douglas-fir and Ponderosa pine stands, particularly when shrubs and / or grasses are productive.

In western Oregon, western tanagers were not observed using the grass and forb successional stages, but were observed foraging in areas not used for nesting, such as shrub / sapling and young 2nd growth ( 16 – 40 years old ) stands typically made up of Douglas-fir.

Western tanagers occurred at an average density of 53. 2 birds / 100 ha in sawtimber Douglas-fir stands (> 80 – 150 years old ), 37. 0 / 100 ha in mature Douglas-fir stands (> 100 years old ), and 3. 1 / 100 ha in sapling Douglas-fir stands (< 20 years old ) in northern California.

In 35-to 45-year-old Douglas-fir and red alder-dominated stands, an average of 322 % more western tanagers were detected on sites logged to a density of 240 to 320 trees / ha, and an average of 363 % more western tanagers were detected on sites logged to a density of 180 to 220 trees / ha, compared to controls with 410 to 710 trees / ha.

In Arizona, western tanager occurred at significantly ( p < 0. 05 ) higher densities ( 15. 8 / 40 ha ) in forest dominated by Douglas-fir and ponderosa pine the year after logging to an average of 167. 7 trees / ha compared to control stands ( 7. 7 / 40 ha ) with average tree density of 626. 2 trees / ha.

Northern Spotted Owls occur in ponderosa pine / Douglas-fir ( Pinus ponderosa / Pseudotsuga menzeizii ) forests in the eastern Cascade Ranges of Washington and in Douglas-fir / evergreen hardwood forests in northwestern California.

In addition, western tanager was significantly ( p < 0. 05 ) positively associated with large saw timber (> 20 % cover, > 21 inch (> 53. 2 cm ) mean dbh ) and significantly ( p < 0. 05 ) negatively associated with pole timber (> 20 % cover ; conifers > 10 feet (> 3 m ) tall and 4 – 12 inch ( 10. 2 – 30. 4 cm ) mean dbh ; hardwoods 10 – 50 feet ( 3 – 15 m ) tall and 4 – 12 inch mean dbh ) stands dominated by Douglas-fir, western hemlock ( Tsuga heterophylla ), and red alder in the central Oregon Coast Ranges.

In a nearby mixed-conifer forest, nests were found in Douglas-fir and ponderosa pine ( P. ponderosa ).

Ponderosa Pine-Gambel oak ( Q. gambelii ) and mixed-conifer forests, typically dominated by Douglas-fir and / or white fir ( Abies concolor ), are often used.

Low Northern Spotted Owl reproductive output in Douglas-fir / hardwood and mixed-conifer forests of northwestern California was associated with cold, wet springs.

Northern Spotted owl survival in Douglas-fir / hardwood and mixed-conifer forests of northwestern California was detrimentally affected by cold, wet springs.

For example, data from Douglas-fir / hardwood and mixed-conifer forests of northwestern California suggest that decreases in Northern Spotted Owl survival associated with cold, wet weather were more gradual in landscapes with features considered high quality compared to landscapes with low-quality features.

However, relationships between roost sites and climatic variables were weak in mixed-conifer and Douglas-fir forests in southwestern Oregon.

In Douglas-fir / hardwood, mixed-conifer, and Oregon white oak forests of California, 500 acre ( 200 ha ) plots centered on nesting and roosting sites contained significantly ( P = 0. 003 ) more mature and old-growth habitat than random plots.

In mixed-conifer and Douglas-fir forests of southwestern Oregon, home range size was inversely correlated ( r =- 0. 83 ) with the percentage of old-growth habitat.

Northern Spotted Owl home range size in Douglas-fir and mixed-conifer study areas in southwestern Oregon and northwestern California was inversely correlated with proportion of woodrats ( Neotoma spp.

The 1, 700-ha area of old growth used by Northern Spotted Owls in western hemlock forests of Washington was much greater than the 500-ha area of old growth used in mixed-conifer and Douglas-fir forests of Oregon, possibly due to the greater prey biomass density in the Oregon study area ( 388 g / ha ) than the Washington study area ( 61 g / ha ).

In Douglas-fir / hardwood and mixed-conifer forests of northwestern California, Northern Spotted Owl nest sites were significantly ( P < 0. 01 ) less fragmented than random plots at approximately 500 acre ( 200 ha ) and 1, 100 acre ( 450 ha ) scales.

Effects at large scales were observed in mixed-conifer and Douglas-fir landscapes in southwestern Oregon.

For example, in coniferous forests in southwestern Oregon, Northern Spotted Owl home range size varied from 1, 320 acres ( 533 ha ) in clumped mixed-conifer forest to 7, 190 acres ( 2, 908 ha ) in fragmented Douglas-fir forest.

In mixed-conifer and Douglas-fir forests in southwestern Oregon, density of resident Northern Spotted Owl pairs ranged from 0. 046 pairs / km² in fragmented Douglas-fir forest to 0. 190 pairs / km² in clumped mixed-conifer habitat.

In mixed-conifer and Douglas-fir forests of southwestern Oregon, Northern Spotted Owl roost sites averaged 45 feet ( 13. 7 m ) above ground and ranged from ground level to 256 feet ( 78 m ).

In mixed-conifer and Douglas-fir forests of southwestern Oregon, 46 % of Northern SpottedOwl roost sites were in Douglas-fir.

Pseudotsuga menziesii, known as Douglas-fir ( in the UK, ' Douglas fir ' without the hyphen ), Oregon pine, or Douglas spruce, is an evergreen conifer species native to western North America.

Mice, voles, shrews, and chipmunks consumed an estimated 65 percent of a Douglas-fir seed crop following dispersal in western Oregon.

The nearby Olympic National Forest lands Douglas-fir, blooming pacific rhododendrons in May and June, salal, and Oregon Grape.

In west-central Oregon, an old-growth Douglas-fir forest was clearcut and monitored through 10 years of succession.

In northwestern Oregon, winter foods include needles and tender bark of Sitka spruce, Douglas-fir, and western hemlock ( Tsuga heterophylla ); leaves and green twigs of salal ; buds, twigs, and bark of willows ; and green herbs.

With fire suppression and conversion to agriculture, Garry oak woodlands and bunch grass prairies were invaded by Douglas-fir, Oregon ash ( Fraxinus latifolia

Bird communities in commercially thinned and unthinned Douglas-fir stands of western Oregon.

Western tanager nesting was confined to older 2nd-growth (> 40 years ) and mature ( 120 + years ) Douglas-fir ( Pseudotsuga menziesii ) communities in the western Cascade Range in Oregon.

Although western tanagers occurred at higher densities in young Douglas-fir forest in Oregon, the stands were 40 to 72 years old.

In Oregon, California, and most of Washington, more than 80 % of Northern Spotted Owl nests occurred in Douglas-fir.

The study took place in the White River and Lussier River Watershed, southeastern British Columbia, in a forest dominated by Douglas-fir, white spruce, and western larch.

For instance, in a California mixed conifer-oak forest consisting mainly of white fir, Douglas-fir, incense-cedar, and California black oak, about 47 % of western tanager foraging observations were gleaning, about 40 % were hawking, while lunging and hovering occurred in about 6 % and 7 % of observations, respectively.

Tree species include hemlock, spruce, white cedar, pine, Douglas-fir, and larch or tamarack.

In Douglas-fir, ponderosa pine, and white fir dominated forests of the Sierra Nevada, early-successional stands including clearcuts, shrublands, and plantations were avoided by foraging individuals.

Several sources note Mexican Spotted Owls ' use of large, mature trees, including roosting in areas with high densities of relatively large Douglas-fir and southwestern white pine ( Pinus strobiformis ) in coniferous forests of New Mexico.

Habitat associations in Arizona and New Mexico, 50 % of nests were in Douglas-fir, 20 % in Gambel oak, and 19 % in white fir.

A study in ponderosa pine-Gambel oak communities found 6 of 11 nests in Gambel oak and the rest in ponderosa pine, while in the Tularosa Mountains of New Mexico, 78 % of nests were in Douglas-fir, 11 % were in white fir, 7 % were in ponderosa pine, and 4 % were in southwestern white pine.

Finally, alpine uplands known as ' The Bowl ' exceeding elevations of are clothed with denser forests of ponderosa pine ( Pinus ponderosa ), southwestern white pine ( Pinus flexilis ), and Rocky Mountain Douglas-fir ( Pseudotsuga menziesii subsp.

The five are opportunities for recreation such as white water rafting near the Portland metropolitan area ; anadromous fish habitat supporting wild late winter coho, spring chinook, and winter steelhead ; habitat for the federally threatened Bald Eagle and Northern Spotted Owl and potential habitat for the threatened Peregrine Falcon ; the forests of old-growth Douglas-fir along its banks ; and historic importance.

In eastern Washington that typically means replacing Douglas-fir or true fir stands with ponderosa pine, western larch, western white pine, lodgepole pine, western red cedar, alder, or spruce.

At higher elevations, associates include southwestern white pine ( Pinus strobiformis ), Rocky Mountain Douglas-fir, ( Pseudotsuga menziesii var.

At mid-elevations sugar pine, incense-cedar, white fir and Jeffrey pine join Douglas-fir, ponderosa pine, and canyon live oak, while the other pines and oaks drop out of the mix.