Douglas Fir

Habitat and Ecology

The Douglas fir is in the pine family with a species classification of evergreen conifer. There are two different geographic variations of the Douglas fir, one being the Coast Douglas fir found on the Pacific coast of California, central California, and western parts of Nevada and the other being the Rocky Mountain Douglas fir found in the Pacific Northwest area as well as British Colombia. These trees grow in a variety of different habitat conditions from the coast to mountainous areas. Alike their range in habitat, the species has a wide range of climate areas. Coast Douglas fir’s experience cold wet winters with warmer and drier summers, while the Rocky Mountain Douglas fir’s experience more intense and continual cold climates. Across both variations they share the commonality of growing in areas not susceptible to drought that provide a large surplus of precipitation.

A wide range of other species rely on the Douglas fir through providing nesting areas for the northern spotted owl, seeds for food for small animals like squirrels, rabbits, and birds, and foliage to eat for elk, mountain goats, antelope, and many other species. Douglas firs also provide many ecosystem services such as providing habitat for species to aid in sustaining biodiversity, mitigating climate change through improving air quality, filtering storm water runoff, and improving the integrity of soil to aid in erosion prevention.

History

The Douglas fir species is native to the Boise area, being found all throughout the state of Idaho as well as the Pacific Northwest as a whole.  It is currently the most common forest type found throughout Idaho. Over the last couple decades the amount of Douglas firs in the state have been able to increase due to widespread fires clearing out other tree types and opening up the opportunity for this species to occupy the area.

Values

The Douglas fir has a very large economic value as it is one of the most utilized trees in the United States for lumber production. It is a valuable commercial timber that is commonly used for construction and building.

The Douglas fir holds a very important cultural significance in that nearly half of all Christmas trees in the United States are Douglas firs. The Douglas fir also holds cultural value especially to indigenous people who utilized the tree in a multifaceted manner for fires, shoes, housing, fishing tools, and medicine. The needles of the tree were used to treat many ailments such as the common cold, asthma, headache, liver issues, and arthritis.

The forests that these trees make up hold a social value. These forested areas provide us with spaces of nature for recreation, such as hiking, skiing, snowboarding, mountain biking, and many other activities. These services are largely appreciated and utilized especially in Idaho. 

Challenges and Management

One threat to the Douglas fir species is wildfires. Though the trees have thick bark that enables them to withstand a certain degree of fire, since wildfire intensity has increased with the increase in severity of our climate crisis it is possible that the fires have pushed some area’s ability across the threshold of regeneration. Fire damaging already existing Douglas firs, seeds, and landscape has led to decreased seed availability and areas being unsuitable to foster growth. Douglas firs also face challenges due to the increase of droughts. Due to the trees natural sensitivity to drought, the species has faced threats as yearly precipitation decreases and slows the growth rates of the trees. It is projected that as drought conditions increase from the climate crisis, the growth of Douglas firs will decrease. Due to location, the majority of these trees are managed by a number of different agencies such as the Bureau of Land Management, the National Parks Service, and the U.S. Fish and Wildlife Service. 

Sources

Arbor Day Foundation. Douglasfirpseudotsuga menziesii. Douglasfir Tree on the Tree Guide at arborday.org.  https://www.arborday.org/trees/treeguide/treedetail.cfm?itemID=83 

CRD. Douglas-Fir Ecosystem.- crd.bc.ca.  https://www.crd.bc.ca/docs/default-source/es-harbours-pdf/may19-2021-ecosysteminfosheets-coastaldouglas-fir.pdf?sfvrsn=5fa94ccd_0 .

 Davis, K. T., Dobrowski, S. Z., Higuera, P. E., Holden, Z. A., Veblen, T. T., Rother, M. T., Parks, S. A., Sala, A., & Maneta, M. P. (2019, March 26). Wildfires and climate change push low-elevation forests across a critical climate threshold for tree regeneration.  https://www.pnas.org/content/116/13/6193 .  

Environmental Monitor. Douglas fir trees threatened by increasing droughts. (2016, September 15).  https://www.fondriest.com/news/douglas-fir-trees-threatened-increasing-droughts.htm .  

 Idaho Forests Products Commission. Douglas fir · Idaho Forests Products Commission. (2018, February 7).  https://www.idahoforests.org/content-item/douglas-fir/ .

Pacific Forest Trust. Douglas fir. (2018, August 22).  https://www.pacificforest.org/habitat/douglas-fir/ .  

Sierra Club BC. Douglas-fir.(2020, December 16).  https://sierraclub.bc.ca/douglas-fir/ .