Since 1991, the PROBE (PRotocol for Operational Brushing Evaluations) project has studied the effects of operational brushing treatments on conifer seedlings and vegetation. This project currently includes experiments on 96 sites across the southern interior of BC, and 10-year data is being collected at many of these sites. The results are providing forest managers with valuable guidance regarding a) where brushing is and is not required, b) the selection of appropriate treatments, c) expected conifer and vegetation responses, d) the effects of treatment on forest health, and e) the effects of treatment on non-timber site values. PROBE sites that have already yielded 10 years of data now have the potential to provide valuable information about the long-term effects of brushing on conifer growth and yield, stand dynamics, and plant community development and diversity at relatively low cost. Data regarding the effects of brushing treatments on growth and yield and stand development have a number of important potential uses. Firstly, it can be used to validate existing policy and regulations or to suggest appropriate changes. This is especially important for broadleaf complexes because of the long time period during which conifers and broadleaves interact, because of the controversy that currently exists regarding appropriate levels of broadleaves that can be retained at free-growing, and because these complexes occur in some of the most productive ecosystems in BC. Broadleaves are well known for their contribution to ecosystem health (e.g., Gerlach et al. 1997; Simard et al. 2001; Aitken et al. 2002; Delong et al. 2002; Baleshta et al. 2004) but policy makers are hesitant to alter the free-growing guidelines without firm information regarding the effects on stand development and conifer yield. A second use of our growth and yield data is in the development and calibration of stand development models that predict the effects of silvicultural treatments on growth and yield, stand structure, and forest health over one or more rotations. Managers would find such models extremely useful for conducting accurate cost-benefit analysis regarding different treatment options, and for predicting stand development. At present, the PROGNOSISBC and SORTIE-BC models appear well suited to this purpose.
J. Heineman Forestry Consulting.
J. Heineman Forestry Consulting. 2006. Long-term effects of vegetation management treatments on growth and yield and stand development. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2006MR140