Overview - Opax Mountain Research Project

The Interior Douglas-fir forests occur throughout the lower slopes of the the Thompson, Nicola and Columbia River basins, and the Cariboo Plateau. The climate is warm and dry in summer and cool with a moderate amount of snow in winter. Douglas-fir is the dominant tree species with trembling aspen scattered through out and lodgepole pine on cooler sites. Hotter and drier areas are dominated by grassland and open ponderosa pine forests while hybrid white spruce and white birch occur where it is wetter and cooler.

All forest ecosystems undergo periodic disturbances. In dry Interior Douglas-fir forests, the most common natural disturbances include defoliating insects and bark beetles, windthrow, root disease and wildfire. Disturbances are important to the ecological processes that maintain the diverse flora and fauna in the Interior Douglas-fir ecosystems. Naturally occurring disturbances, along with logging, fire suppression and range use, shape the way our forests look and evolve.

In the Opax Mountain Area, six harvesting treatment were designed to create a range of structural conditions found naturally in Interior Douglas-fir forest stands.


Control, no treatment Used as a baseline area against which results will be compared.	Low volume removal (20%) spread uniformly across the treatment area; all large trees (>50cm dbh) harvested as a single tree system.


Low volume removal (20%) spread uniformly across the treatment area; all large trees (>50cm dbh) harvested as a single tree system.	Moderate volume removal (35%) large (>35 cm dbh) diameter merchantable timber removed but leaving 0.1 to 1.0 ha unharvested patches centered around snags and large trees.


High volume removal (50+%) removing large merchantable timber spread uniformly across the treatment area. Large (>35cm dbh) trees harvested as a single tree system.	High volume removal (50+%) as patches. Three patch sizes were used: 0.1 ha, 0.4 ha, and 1.6 ha.

For general information about the studies, please contact:
Andre Arsenault
Southern Interior Forest Region
515 Columbia Street, Kamloops, BC V2C 2T7