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Coram Experimental Forest

Coram Experimental Forest lies within the Flathead National Forest in the Northern Rocky Mountains of Montana. Spanning 7,500 acres (3,020 hectares), Coram Experimental Forest was established in 1933 for researchers to study western larch regeneration and management. Today, the research conducted and the extensive datasets collected at Coram continue to be critical for western larch management.  

Check out the Coram Experimental Forest Brochure for more information.  Check out the Coram Experimental Forest Brochure for more information.

Background Information and History

Map of the Coram Experimental Forest

For more than 60 years, Coram Experimental Forest is used by scientists for research, education and conservation, as well as by recreationalists for activities including hiking, biking, hunting, horseback riding, fall color peeping, and wild berry collecting. Coram was established in 1933 on the Flathead National Forest in northwest Montana as an area representative of the western larch (Larix occidentalis Nutt.) forest cover type distributed within the upper Columbia River basin. At the Coram Headquarters on the Hungry Horse District Ranger Station adjacent to the Experimental Forest boundaries, the International Larix Arboretum contains specimens of many larch trees of the world.  Coram Experimental Forest offers educational opportunities in the award-winning Walk With Larch Trail, which demonstrates the long-term effects of numerous silvicultural and forest management choices. Additionally, in the autumn, the western larch tree foliage turns golden throughout the experimental forest, providing an opportunity for recreational viewing.

The Coram Experimental Forest represents western larch-mixed conifer forests of the Northern Rockies. The western larch forest cover type is diverse and productive, making it highly valuable for land managers for timber production. Western larch is a tree species that regenerates well in the exposed soil and sunny conditions that are typical after a fire or other disturbances, making it important for reforestation efforts. Research at Coram has historically centered around the regeneration, ecology, and management of this important and valuable species. For example, the long-term silvicultural studies are allowing researchers and managers to understand the effects of multiple entries into stands on soil and forest productivity, as well as the potential of various silvicultural approaches to designing restoration of wildlife habitat.  Within the Coram Experimental Forest, the Coram Research Natural Area contains old, large forest used as a reference site for comparison to managed areas. 

Ecology

Climate 

Climate at Coram Experimental Forest is classified as a modified Pacific maritime-type. Occasional winter, continental-type polar air moves westward over the Continental Divide, and temperatures drop substantially for a few days. Annual precipitation ranges from an average of about 35 inches (890 mm) at the lowest elevations, to 50 inches (1,270 mm) at the higher elevations. Precipitation falls mostly as snow. May through August mean temperature is about 61 °F (16 °C ). Winter temperatures average about 20 °F (-7 °C ). Growing season length (the number of frost-free days) ranges from 81-days near Abbot Creek, to about 160-days on a nearby east-facing slope.  

people overlooking Coram experimental forest

Coram Experimental Forest hosts a diversity of tree species and other vegetation. The prominently western larch puts on a show in the fall.

Vegetation

Coram Experimental Forest has a diverse mix of plants. Western larch (Larix occidentalis) grows almost everywhere at Coram with Douglas-fir (Pseudotsuga menziesii), subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii). Hybrids of P. engelmannii and P. glauca (white spruce) grow at lower elevations. Less common plants are lodgepole pine (Pinus contorta), western white pine (Pinus monticola), western hemlock (Tsuga heterophylla), and western redcedar (Thuja plicata). Western larch (L. occidentalis) and ponderosa pine (Pinus ponderosa) grow together on dry, lower-elevation ridges that have shallow soil, the only sites where ponderosa pine grows. At high elevations, larch grows with whitebark pine (Pinus albicaulis), a species nearly eliminated from Coram by white pine blister rust (Cronatrium ribicola).  See Coram Experimental Forest: 50 years of research in western larch forest for a full survey of tree, shrub, forb, and non-native plant species found in the Experimental Forest.  

Soils & Geology

Coram Experimental Forest has rich loamy soils. Soil depths range from a few centimeters on steep, upper slopes to over 9 ft (3 m) on gentle, lower terrain. A rock layer primarily made of argillite and quartzite underlies most of the upper slopes. The lower areas have deposits of glacial outwash and till. A thin layer of volcanic ash covers about half of the forest.   

Elevation & Topography

Coram Experimental Forest is transected by Abbot Creek and it's tributaries, resulting in steep gradients. Elevation ranges from 3,300 ft (1,006 m) near the drainages to 6,370 ft (1,942 m) atop the slopes. 

Facilities Information

Coram Experimental Forest headquarters in Hungry Horse, MT

Coram Experimental Forest headquarters are located on the grounds of the Hungry Horse Ranger District, roughly 3 miles (5 km) west of the experimental forest. They include two houses built around 1948 by the Federal Bureau of Reclamation during the construction of the Hungry Horse Dam. The houses function as offices and sleeping quarters for Rocky Mountain Research Station staff and collaborators. Please contact the manager with questions concerning housing for activities related to cooperative research.

Coram Experimental Forest has approximately 33 miles (54 km) of roads. Two roads—FS 497 (the Desert Ridge Road) and FS 38 (the South Fork Road) are open to the public. Except for limited administrative access, all other roads in Coram are closed to motor vehicle use due to grizzly bear habitat restrictions. 

Visitor Information

Located only 11 mi (18 km) west of Glacier National Park, there are many reasons to visit the Coram Experimental Forest: 

A photo of the International Larix Arboretum at Coram Experimental Forest.
  • Walk With Larch Trail: Walk With Larch is a self-guided trail that provides opportunities for students and forest visitors to explore this unique area. A brochure can be picked up at the Hungry Horse Ranger District office or downloaded above.
  • International Larix Arboretum: This arboretum houses the world’s ten species of larch. The arboretum is located at the Hungry Horse District Ranger Station adjacent to the Experimental Forest boundaries.
  • Coram Research Natural Area: The Coram Research Natural Area includes 200+ year-old stands of late-successional western larch and Douglas-fir.
  • Recreation: Recreational activities in the Coram Experimental Forest include hiking trails, biking and horseback riding on gravel roads, wild berry collecting and big game and upland bird hunting.

Frequently Asked Questions

Q: I want to do research at Coram. Whom do I contact?

A: Research at Coram is coordinated through the Scientist in Charge.

Q: How can I reserve the Coram housing facilities located on the Hungry Horse Ranger District administrative site?

A: The houses are reserved for administrative use by research staff and cooperators and not available to the public. Researchers should contact the Manager to schedule use of the houses.

Q: Can I camp, build a campfire, or collect firewood on Coram Experimental Forest?

A: No, these activities are not permitted on the experimental forest to help preserve the integrity of the past and present research studies and to minimize the disturbance to the current natural ecological conditions for future studies.

Historical Research

Research began on the Coram Experimental Forest (CEF) in 1948 to study western larch management. The focus of the research has expanded over time to include topics such as climate change, wildlife habitat, and restoration activities.  

Coram Experimental Forest Research Timeline:

  • 1950s: Researchers studied how to regenerate western larch and the conifers that grow along with them using even-aged methods of harvest cutting, also known as clear-cutting. Researchers coupled this with a wide range of site preparation treatments, including burning.
  • 1960s: Researchers determined how to regenerate larch by seeding and planting, and how the growth of young larch forests, grown under a wide range of stand densities, respond as individual trees and as stands.
  • 1970s: Studies featured multidisciplinary research in using forest residues and developing forest productivity. Researchers evaluated water use, soil conditions, forest living matter, understory plants, and tree characteristics.
  • 1980s: Researchers studied late-ecosystem-stage changes within the Coram Research Natural Area, cone production in young larch stands, and differences in bird populations within logged and unlogged areas.
  • 1990s-2000s: Ongoing long-term studies continued and efforts to share results through conservation education locally, regionally, and internationally were expanded. Researchers performed the last active treatment on the Coram Experimental Forest in 2000. Due to several staff retirements, personnel reassignments, and conflicting priorities, work on the CEF slowed in the 2000s.
  • 2010s: People have recognized this forest type’s importance to wildlife habitat and its potential loss due to changing climate, leading to increased attention to the need for restoration approaches. CEF and its cache of long-term experimental silviculture studies can provide valuable guidance for restoration management. 

Ongoing Research

Today, research conducted at Coram Experimental Forest includes questions about managing forests for climate change resiliency and adaptation, wildlife habitat, prescribed fire, carbon sequestration, soils and more. Additionally, Coram has long-term monitoring and research projects that began 40+ years ago and continue to be monitored today. These studies are on-going and provide insights about legacy effects of forest management actions on the ecosystem that are valuable for informing contemporary forest management.

Some recent and ongoing collaborative studies being conducted at Coram Experimental Forest are described below:

The Northern Rocky Mountains Adaptive Silviculture for Climate Change (ASCC) Study: This study is located on the Hungry Horse Ranger District of the Flathead National Forest, and partially on Coram Experimental Forest. As outlined on the associated Project Page, the intent of the study is to provide resource managers with the silvicultural tools and frameworks to manage western larch communities into an uncertain future, culturing varying levels of climate adaptation in forest stands. This study is part of an international network of ASCC sites being evaluated to improve forest management across North America. As of 2021, logging and planting of the experimental units is still in progress.

Pre-commercial thinning effects on snowshoe hare (Lepus americanus) habitat: Evaluating snowshoe hare usage of plots on pre-commercially thinned larch-mixed-conifer stands to determine which treatments might be applicable for snowshoe hare/Canada lynx habitat restoration. Data is being synthesized for publication.

Monitoring Forest Recovery and C & N Pools 30 Over Years: This study takes advantage of a long-term study installed at the CEF in 1974 to address contemporary and critical management information needs about the sustainability of harvesting forests for biomass utilization. The original treatment included three regeneration harvest types (clearcut, group selections, and shelterwood), three biomass removal levels (high, medium, and low) combined with prescribed post-harvest burning treatments (burned and unburned). Plots were re-measured in 2012. Several recent papers summarize long-term effects and outcomes of biomass removal on forest ecosystem and soil in Coram (Woongsoon et al. 2015a, 2015b, 2016a, 2016b, 2017).

Influence of thinning density in young western larch stands on individual tree and stand growth, 1961-present: Long-term analysis: In 1961 a study was installed in 10-year old second-growth larch stands to determine the trade-offs between individual tree growth and stand yield that were pre-commercially thinned at varying densities. The study was remeasured every five years until 2000 and then again in 2015. Publications on describe the influence of thinning densities on stand characteristics and above-ground Carbon distribution. 

Coram Research Natural Area

In 1938, 339 ha (838 ac) in the southeastern corner of Coram Experimental Forest was reserved to preserve examples of late-successional western larch and interior Douglas-fir stands. Approximately 80 percent of the natural area is forested with 200+ year-old stands of mixed western larch and Douglas-fir. It was officially recognized as the Coram Research Natural Area (CRNA) in 1988 and provides a reference site to compare to managed forest areas.

Long-term Monitoring and Data

Coram Experimental Forest has long-term datasets (some 60+ years old) on climate, precipitation, streamflow, tree density/characteristics, and woody biomass accumulation. The Experimental Forest and Range network encourages re-use of data from among its collaborators. We also recognize that it is important for scientists to receive proper credit for the contribution their data make to other projects. Thus, the data user must properly cite the data publication in any other publications or in the metadata of any derived products developed using Forest Service data (Conditions of Use).  

Weather  Data

Scientists have maintained two weather stations, Desert Ridge (elevation 6,000 ft, 1,830 m) and Terrace Hills (elevation 3,500 ft, 1,070 m), at the Coram Experimental Forest since 1986. Available weather data includes precipitation, air temperature, relative humidity, soil temperature, wind speed, wind direction, and solar radiation. Daily meteorology data for Desert Ridge and Terrence Hills weather stations: 1996-2015 is available for download. For access to any additional data, please contact the Coram Experimental Forest Manager.

Parshall Flume

Streamflow Data

Hydrologic flow measurements on the Abbot Creek and the Lunch Fork of Abbot Creek began in 1974. Both Abbot Creek and the Lunch Fork of Abbot Creek currently contain a one-foot Parshall flume. The Abbot Creek flume is located approximately 200 meters downstream from the spring-fed source of Abbot Creek. The Lunch Fork flume is located on the Lunch Fork of Abbot Creek just above the confluence of Abbot Creek and the Lunch Fork. A sediment dam was constructed in 1974 immediately above the Abbot Creek flume to prevent sediment build-up in the flume.  Streamflow data from 2004-2017  reported every 15 minutes for these two sites, are available for download.

Snowfall Data

The Emery Creek SNOTEL site, a meteorological station maintained by the Natural Resources Conservation Service near Coram Experimental Forest, monitors accumulated precipitation, snow depth, snow water equivalent, and temperature. There is also a snow course located along Desert Ridge where snow depth and water content values are measured and calculated to augment the SNOTEL site.

Western Larch Spacing & Thinning Data

In 1961, researcher established four replicate sites to study thinning treatments and stocking levels of western larch. Multiple long-term datasets emerged from this study, including:

Long-term Vegetation Monitoring

In 1985, researchers established four long-term baseline vegetation monitoring plots within the Coram Research Natural Area; four additional plots were established in 1993. Researchers re-measured all plots in 2014. They recorded stand dynamics and photopoints at each plot. Vegetation data available upon request.

researchers in front of a weather station

Coram Experimental Forest provides the ideal setting to answer study questions related to 

forest restoration, the effects of climate change on ecosystems or plant communities, prescribed fire, species adaptation, plant ecology, hydrology, watersheds, sedimentation, forest management techniques, animal ecology, and more. We welcome future research projects and collaborations that fit within the overall research goals of the Rocky Mountain Research Station and are compatible with other ongoing research at Coram. All research conducted at Coram Experimental Forest requires an approved study plan, regardless of type, extent, duration, or impact. Data collected at Coram for use in any publication or product must be submitted to the Forest Service Research Data Archive for a data DOI (how to submit data). It is routine professional ethics to acknowledge RMRS, Coram Experimental Forest, and the efforts of collaborating Forest Service scientists and staff in any subsequent publications. Please also forward subsequent publications to RMRS collaborator.  

 

Contact Scientist-in-charge Justin Crotteau for more information on research opportunities, setting up a study plan, or archiving data collected at Coram Experimental Forest. 

Key Personnel

Scientist in Charge

Manager

  • Person
    David K. Wright

    David K. Wright

    Ecologist
    https://research.fs.usda.gov/about/people/david.wright2

Collaborators

Projects

Understory Publications

External Publications

Treesearch Publications

Last updated January 22, 2024
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