Boise Basin Experimental Forest

A map of Boise Basin Experimental Forest shows the three units (Headquarters Unit, Bear Run Unit, and Bannock Creek Unit) surrounding Idaho City.

The Boise Basin Experimental Forest lies near the small town of Idaho City, Idaho, approximately 30 miles northeast of Boise, Idaho. Established in 1933 to study management of ponderosa pine (Pinus ponderosa), Boise Basin consists of 8,740 acres (3,540 ha). Early research at Boise Basin was on timber production, slash disposal, and ponderosa pine regeneration. The experimental forest is divided into three units—Bannock Creek, Bear Run, and Headquarters, which surround Idaho City. The Headquarters unit contains the old headquarters facilities, which are now administered by the Idaho City Ranger District. This small unit has a mixture of climax ponderosa pine and Douglas-fir as well as ponderosa plantations that were terraced in the 1950s. The Bear Run unit is a younger ponderosa pine climax forest, with trees that are 80 to 100 years old. The Bannock Creek unit contains old ponderosa pine with younger Douglas-fir in the understory. The Bannock Creek unit is on steeper slopes and has many undisturbed areas, including Bannock Creek Research Natural Area. 

The Boise Basin Experimental Forest has had a history of disturbance and mixed uses. Idaho City was a booming mining town in the 1870s, and mining caused major impacts on the two units north of Idaho City. The majority of trees in these units now are the result of post-mining regeneration. As part of the Boise National Forest, Boise Basin regularly experiences heavy recreational use by the public with activities including: fishing, hiking, biking, horseback riding, camping and hunting—as well as panning for gold on Bannock Creek. Today, research at Boise Basin focuses on multiple use management, wildland-urban interface, forest restoration, erosion control, and wildlife habitat. 

Ponderosa pine dominated forest in Boise Basin Experimental Forest

Climate 

Boise Basin has warm, dry summers and cool, wet winters are the usual climate. Annual precipitation averages 25 inches (635 mm), with the most falling from October through June. Downpours and severe lightning can arrive in summer. Temperatures average 24.8 °F (-4 °C) in winter and 66.2 °F (19 °C) in summer.

Vegetation

Interior ponderosa pine dominates the forest cover at Boise Basin. Prior to successful fire exclusion, frequent surface fires maintained the pine with patches of quaking aspen. Douglas-fir occupies many settings, with mountain shrubs occupying the cooler aspects and shallow soils. For more information, see this species list of vascular plants, bryophytes, lichens, and fungi that have been recorded within Boise Basin Experimental Forest. 

Soils

Soils come from granitic rocks of the Idaho Batholith. They are generally deep and mostly Typic or Lithic Xeropsamments, Cryumbrepts, Cryoboralls, Cryorthents, and Cryocrepts with pH ranges from 5.5 to 7.0. The 50-year ponderosa pine site index ranges from 53 to 66.

Elevation

Elevation in Boise Basin ranges from 1,200 to 3,630 m (3,937-11,909 ft). 

Although they are situated within the experimental forest boundaries, facilities on Boise Basin are administered by the Idaho City District. Research collaborators can request the use of housing facilities on the Boise Basin Experimental Forest through the Boise National Forest Idaho City District.

Historical Research

The earliest studies, beginning in 1933, evaluated different methods of selecting mature trees for harvest and the effects of remaining tree patterns on tree growth, reproduction, and understory plants. Crews installed permanent transects for monitoring tree reproduction and understory plants. Subsequent studies evaluated factors affecting germination, survival, and growth of young ponderosa pine, and the life histories of trees and understory plants in ponderosa pine forests. Researchers investigated competition factors for planted and natural pine seedlings in 1937. Two later studies examined seed storage, viability, germination, root systems of trees and seedlings, porcupine feeding relationships with ponderosa pine, and thinning and pruning methods.  Later studies of timber production compared using individual tree to group selection harvest methods; viability of seeds stored in soil; site preparation methods for tree planting; tree seed dispersal; applying plant hormones; and converting old-growth stands to second-growth.

Current and Ongoing Research

A forester taking tree measurement on the Experimental Forest.

Research at Boise Basin has provided important information on ponderosa pine management, habitat types in dry forests, ponderosa pine regeneration, and response of ponderosa pine to prescribed fire. Ongoing monitoring and research project include:

• Forest Restoration: Developing practices to encourage integrated restoration in dry-mixed conifer forest planning
• Forest Resiliency to management and climate change: Investigating different methods to create more resilient ponderosa pine forests - such as forest floor treatments, mid-story treatments, and overstory canopy treatments - on more than 1976 acres (800 ha) on the Bannock unit
• Investigating fuel treatments: Fuel development over time, including when and how they should be maintained
• Forest Management and Canopy Openings: Studying tree and understory response under different canopy openings
• Long-term growth and stand development: Monitoring long-term plots
• Surface, Terrain, and Canopy Height Models: These data publications each contain three raster datasets with a spatial resolution of one meter: 1) a digital surface model (DSM), which represents the highest lidar return in each grid cell; 2) a digital terrain model (DTM), a representation of the ground surface with vegetation and other non-ground returns removed; and 3) a canopy height model (CHM), a representation of the height of vegetation above the ground surface. Data can be found here: Boise Basin Experimental Forest digital surface, terrain, and canopy models in 2018; Bannock Creek unit of Boise Basin Experimental Forest digital surface, terrain, and canopy models in 2007)
• Runoff and erosion from small forest watersheds on the Boise Basin Experimental Forest: dataset

Conducting Research

Due to its history of disturbance and heavy recreational use, Boise Basin has research opportunities related to ponderosa pine restoration, the wildland-urban interface, and recreation. 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 Boise Basin. All research conducted at Boise Basin Experimental Forest requires an approved study plan, regardless of type, extent, duration, or impact. Data collected at Boise Basin 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, Boise Basin 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 Boise Basin Experimental Forest. 

Long-term databases on historical fire return intervals, soils, habitat types, and vegetation trends at Boise Basin are available. Please contact the scientist in charge for more information. 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).