Predicted Impacts of Hard Pine Rusts in Lodgepole Pine Dominated Juvenile Stands in the Central BC
Project Reference Number: 2004-05
Project Status: Complete
Led by: Alex Woods, Forest Pathologist, Ministry of Forests and Range, SmithersPro-Tech Forest Resources Ltd., Telkwa; Cedrus Consulting, Smithers; Silvicon Services Inc., Smithers
Funder: Forest Investment Account - Forest Science Program
Hard pine rusts can have a large influence on the productivity of juvenile lodgepole pine stands. Because of the devastation in mature and oldgrowth stands due to the mountain pine beetle epidemic, much greater emphasis and reliance will be placed on second growth stands to alleviate timber supply pressures. It is therefore essential that accurate estimates of the productivity of those second growth stands are made.
This project was initiated in order to predict the impacts of hard pine rusts on the timber supply in the Lakes TSA. In 1997, 30 one-hectare stem mapped plots were established in randomly selected juvenile lodgepole pine stands throughout the Lakes TSA. The growth and yield model TASS was used to estimate the timber supply impacts of hard pine rusts; however, in order to do so, assumptions had to be made regarding the time required for rust infected trees to die. TASS model results indicated that the impact estimates due to rusts were sensitive to this “time to death” assumption. The results of this study have been used to refine the Operational Adjustment Factors (OAF1) for managed stands in the Lakes Timber Supply Review (TSR). Specifically the OAF1 estimate for managed lodgepole pine stands was increased to 20% from the provincial default of 15% in the most recent TSR to account for losses due to rusts.
Questions have arisen regarding the validity of the assumptions used in modelling hard pine rust impacts. In 2004, seven years will have elapsed since the time of plot establishment and the initial rust assessment. This current research proposal would involve re-assessing the stem mapped lodgepole pine plots with an emphasis on updating the rust status of the trees. The results from this re-assessment would then be modelled once again in TASS to refine the impact estimate of rusts.