• Estimates of merchantable timber
Deciduous forests in the Quesnel Timber Supply Area are naturally very susceptible to diseases that cause extensive decay and reduce their suitability for timber harvesting. A preliminary analysis based on the current forest inventory and the management practices used to evaluate the sawlog timber supply indicates the timber supply is closely related to the maximum age that these forests are considered to be suitable for timber harvesting. Based on a minimum harvest age of 80 years and an average merchantable volume of 113 cubic metres per hectare, it is estimated that the following timber supply levels could be maintained over the long term:
• no maximum age - approximately 45,200 cubic metres per year
• maximum age 150 years - approximately 42,400 cubic metres per year
• maximum age 120 years - approximately 24,300 cubic metres per year
• Natural transition of deciduous forests to coniferous forests
The current inventory of the predominantly deciduous forests is 10 to 20 years old. Over time, the conifer trees in some of these forests are likely to exceed the growth of the deciduous trees. This would eventually result in a change in the classification of these forests from predominantly deciduous to a conifer forest which would be a candidate for sawlog harvesting.
• Integrated resource management practices
Deciduous forests often occur in riparian areas that provide critical wildlife habitat. Management practices that are more restrictive to timber harvesting than the practices that were used in the sawlog analyses may be required in these areas. This may reduce the available timber supply.
In addition, harvesting of deciduous forests may affect the availability of mature timber for sawlog harvesting, or conversely, harvesting of sawlog forests may limit by the availability of deciduous forests for harvesting. This may occur because of the requirement that cutover areas must be reforested and reach three metres in height before adjacent forests can be harvested.
• Deciduous timber in predominantly conifer forests
The timber volume from deciduous trees growing in predominantly coniferous forests was not included in the analysis of the sawlog and problem forest type timber supply, or in the above estimates for the predominantly deciduous forests. Currently, when these forests are harvested, the deciduous trees are not utilized. Some recovery of these trees has occurred recently.
It may be possible to harvest more of the deciduous timber within predominantly coniferous forests without compromising biodiversity or riparian management requirements. This would permit more timber volume to be recovered without requiring additional area to be harvested.
