Jack Dykinga / Douglas firs (Pseudotsuga menziesii) in 'Wall Street' Canyon. Bryce Canyon National Park, Utah, USA, October.

Konstantin Mikhailov / Lake Ann surrounded by Douglas firs (Pseudotsuga menziesii) Silver firs (Abies alba) and other conifers in the area of Rainy Pass of North Cascades National Park, North Cascades National Park, Cascade...

Jack Dykinga / Long Canyon on the historic Burr Trail, with Douglas fir (Pseudotsuga menziesii) against the 'varnished' canyon walls. Grand Staircase-Escalante National Monument, Utah, USA. October 2018.

Jack Dykinga / Long Canyon on the historic Burr Trail, with Douglas fir (Pseudotsuga menziesii) against the 'varnished' canyon walls with sheets of water flowing over the sandstone. Grand Staircase-Escalante...

Marie Read / White-winged Crossbill (Loxia leucoptera), male feeding on Douglas-fir cones, Ithaca, New York, USA, January.

Markus Varesvuo / Coal tit (Periparus ater) feeding amongst Douglas fir (Pseudotsuga sp) cones. Helsinki, Finland. December.

Jack Dykinga / Rays of low sunlight through Douglas fir (Pseudotsuga menziesii) trees in early morning fog, Redwood State and National Parks, California, USA. May.

Jack Dykinga / Rays of low sunlight through Douglas fir (Pseudotsuga menziesii) trees in early morning fog, Redwood State and National Parks, California, USA. May.

Jack Dykinga / Rays of low sunlight through Douglas fir (Pseudotsuga menziesii) trees in early morning fog, Redwood State and National Parks, California, USA. May.

Matthew Maran / Douglas fir (Pseudotsuga menziesii) planted with protective sleeve to prevent browsing, Devon, England, UK, July.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) collecting, Douglas Fir (Pseudotsuga menziesii) cones, Montana, USA.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) feeding on Douglas Fir (Pseudotsuga menziesii) cones, Montana, USA.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) feeding on Douglas Fir (Pseudotsuga menziesii) seeds in cone, Montana, USA.

Stephen Dalton / Douglas fir (Pseudotsuga menziesii) Rookery Wood, Sussex, England, UK, March.

Cheryl-Samantha Owen / Woman walking over a fallen tree trunk in old growth forest of Red cedar trees (Thuja plicata) and Douglas fir trees (Pseudotsuga menziesii) Avatar Grove, near Port Renfrew, Vancouver Island, Canada,...

Konstantin Mikhailov / Mt. Shuksan and the forest of Douglas firs on the shore of Picture Lake, North Cascades National Park – Mt. Baker Recreatation Area, Washington, USA, January 2000. Stiched panorama.

Steven David Miller / Female Bennett's tree kangaroo (Dendrolagus bennettianus) sitting in tree, captive in breeding program, The Wildlife Habitat, Port Douglas, North Queensland, Australia, August

George Sanker / Rocky Mountain Douglas-fir (Pseudotsuga menziesii). Lamar Valley, Yellowstone National Park, Wyoming, USA, May.

Klaus Echle / Weighing cone harvest of Douglas Fir (Pseudotsuga menziesii) trees . Black Forest, Germany, August.

Klaus Echle / Cone harvest from Douglas Fir (Pseudotsuga menziesii) trees, Black Forest, Germany, August.

Michele Westmorland / View of Douglas Bay, Cabrits National Park area. Dominica, West Indies, Caribbean. July 2008.

George Sanker / Black bear (Ursus americanus) cub, brown phase, climbing a mature Douglas fir (Pseudotsuga menziesii) Yellowstone National Park, Wyoming, USA, May

Tim Laman / Red Mangrove (Rhizophora mangle) trees with roots exposed, Peter Douglas Cay, Belize.

Tim Laman / Red Mangrove (Rhizophora mangle) trees with roots exposed, Peter Douglas Cay, Belize.

Donald M. Jones / Black Bear (Ursus americanus) male in Douglas Fir (Pseudotsuga menziesii), western Alberta, Canada

Eric Baccega / Old growth forest with trunk of a Douglas fir in foreground, MacMillan Provincial park, Cathedral Grove forest, Vancouver Island, British Columbia, Canada

Eric Baccega / Gigantic old Douglas fir tree (Pseudotsuga menziesii) in old growth forest, MacMillan Provincial Park, Cathedral Grove, Vancouver Island, British Columbia, Canada

Kirkendall-Spring / Trunks of Douglas fir trees (Pseudotsuga menziesii) Lewis River Valley, Gifford Pinchot National Forest, Washington, USA

Jack Dykinga / Douglas fir tree {Pseudotsuga menziesii} in front of Long Canyon with vertical desert varnish striations, Grand Staircase-Escalante, Utah, USA

Michael Durham / Hoary Bat (Lasiurus cinereus) climbing through a Douglas Fir (Pseudotsuga menziesii) branch, the Hoary Bat Will often roost in the branches of trees in more exposed areas than is typical for most bats...

Michael Durham / Hoary Bat (Lasiurus cinereus) climbing through a Douglas Fir (Pseudotsuga menziesii) branch, the Hoary Bat Will often roost in the branches of trees in more exposed areas than is typical for most bats...

Jack Dykinga / Quaking aspen {Populus tremuloides} Douglas fir {Pseudotsuga menziesii} and Red Gambel oak {Quercus gambelii} trees in autumn colours, Mt Timpanogos, Uinta National Forest, Utah, USA

Adrian Davies / Douglas fir tree in a churchyard, uprooted during storm in February 1990, Surrey, UK.

Barry Bland / New Zealand Forestry Industry, Harvesting of Douglas Fir Trees, Dunedin, New Zealand. 2004. Caterpillar moving log

Barry Bland / New Zealand Forestry Industry, Harvesting Douglas Fir Trees, Dunedin, New Zealand. 2004

Barry Bland / New Zealand Forestry Industry, harvesting of Douglas Fir Trees, Dunedin, New Zealand. 2004

Barry Bland / New Zealand Forestry Industry, Aerial view of Douglas Fir Tree plantation and cleared area, Dunedin, New Zealand. 2004

Barry Bland / High angle shot through Douglas Fir Trees {Pseudotsuga menziesii} Dunedin, New Zealand. 2004

Barry Bland / New Zealand Forestry Industry, felling of Douglas Fir Tree - lumberjack watching tree falling, Dunedin, New Zealand. 2004

Mark Taylor / Douglas fir tree {Pseudotsuga menziesii} in Utah, USA.

Kim Taylor / Woolly aphids covered in wax filaments {Aphididae} on douglas fir tree. UK.

Jim Brandenburg / Douglas Fir (Pseudotsuga menziesii) pair reaching towards the sky, Bryce Canyon National Park, Utah

Yva Momatiuk & John Eastcott / Pond surrounded by trees and wetland vegetation, summer, Douglas Island, Alaska

Jim Brandenburg / Douglas Fir (Pseudotsuga menziesii) tree reaching towards the sky, Bryce Canyon National Park, Utah

Jim Brandenburg / Douglas Fir (Pseudotsuga menziesii) pair reaching towards the sky, Bryce Canyon National Park, Utah

Mark Moffett / Douglas Fir (Pseudotsuga menziesii) canopy, Wind River, Washington

Mark Moffett / Douglas Fir (Pseudotsuga menziesii) canopy, Wind River, Washington

Mark Moffett / Aerial view researcher Joel Clement studying lichen on Douglas Fir (Pseudotsuga menziesii) snag, Wind River, Washington

Michael Quinton / Douglas Fir (Pseudotsuga menziesii) trees casting long shadows in winter, Yellowstone National Park, Wyoming

Mark Moffett / Bark Beetle (Dendroctonus pseudotsugae) larvae riddles Fir trees with channels where larvae will mature, Flat Creek, Idaho

Jeff Foott / Redwood National Park - Rhodedendron {R macrophyllum} and Douglas fir, California, USA

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) feeding on Douglas Fir (Pseudotsuga menziesii) seeds in cone, Montana, USA. October.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) collecting, Douglas Fir (Pseudotsuga menziesii) cones, Montana, USA. October.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) collecting, Douglas Fir (Pseudotsuga menziesii) cones, Montana, USA. September.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) on Douglas Fir (Pseudotsuga menziesii) Montana, USA. October.

Phil Savoie / American red squirrel (Tamiasciurus hudsonicus) collecting, Douglas Fir (Pseudotsuga menziesii) cones, Montana, USA.

Tim Fitzharris / Douglas Fir (Pseudotsuga menziesii) and Coast Redwood (Sequoia sempervirens) trees, Redwood National Park, California

Jim Brandenburg / Douglas Fir (Pseudotsuga menziesii) pair reaching towards the sky, Bryce Canyon National Park, Utah

Kirkendall-Spring / Douglas fir (Pseudotsuga menziesii) branch with cones on white background, Washington, USA. April.

Jack Dykinga / Two fallen Douglas fir trees (Pseudotsuga menziesii) across a forest trail in temperate rainforest, Hoh Rain Forest, Olympic National Park, Washington, USA. June.

Nigel Cattlin / Needle cast (Rhabdocline pseudotsugae) discolouration and symptoms of infection on douglas fir needles

John Shaw / Western hemlock (Tsuga heterophylla) in Douglas-fir forest (Pseudotsuga menziesii), Oregon, USA, June.

John Shaw / Moss-draped Douglas-fir (Pseudotsuga menziesii) in temporate rainforest, Oregon, USA, June.

Jack Dykinga / Bigtooth maple (Acer grandidentatum) trees in autumn amongst Douglas fir (Pseudotsuga menziesii), against canyon wall. Kolob, Zion National Park, Utah, USA. October 1995.