Silvicultural Effectiveness Monitoring (SEM)
Silviculture effectiveness monitoring (SEM) is a program used to determine the results of management activities and analyses the causes of success or failure.
- The program consists of formal assessment of forest sites performed certain time after disturbance (known as Free-To-Grow [FTG] assessments) as well as frequent site visits with or without data collection to track the development and treatment needs before the final assessment.
- The post-assessment analysis compares the results with the objective set for each harvest site in the Forest Operations Prescriptions [FOP]. This analysis is the backbone of our adaptive management process.
- Assessments are conducted on both planned harvest sites and sites affected by major events of natural disturbance, such as wind damage.
- Aside from being a logical forest management activity, SEM is also mandatory as described in the Silvicultural Effectiveness Monitoring Manual for Ontario (2001).
- SEM data is used for many purposes:
> Understanding trends, improving silvicultural decisions and their implementation process.
> Determining site-specific treatment needs.
> Updating Forest Resources Inventory for future planning and modelling.
> Feedback to strategic planning and financial support decisions.
> Reporting to the Ontario Government [AR].
- SEM assessments are carried out typically 10 years after harvest or other disturbance but the timing varies between 3 and 15 years depending on harvest type and objective.
- We normally do not conduct SEM assessments on treatment sites where regeneration is not the primary objective, such as commercial thinning, preparatory shelterwood or selection cut, however, a sample of these treatments is included in our program every year to complement the adaptive management loop.
- Even-aged stands (shelterwood, clearcut) are assessed for Free-To-Grow [FTG] standards by determining if the desired regeneration, judged to be essentially healthy and free from competing vegetation, met the minimum stocking and height, as specified in the silvicultural ground rules [SGR].
- Uneven-aged (Selection) stands are assessed for management standards by determining if the basal are, species composition, stand structure and quality met the standards specified in the silvicultural ground rules [SGR].
- The assessment methodology is evolving. The currently used system is known as “SO_iSTARS” - Site Occupancy Index (SOI) & Silvicultural Treatment Assessment & Reporting. This methodology allows for evaluation of the status of multi-sized regeneration of various species based on data collected in clusters of variable size plots.