Forest Resource Inventory

forest, techician measuring treeThe Forest Resource Inventory (FRI) is an extensive survey of the forest resources of Ontario. It was originally designed in 1946 to locate merchantable timber species for supplying mills.


The FRI was designed as a large-scale survey that would allow general characterization of the forest in terms of species, forest conditions and regeneration. Traditionally, the FRI has been based on aerial photo interpretation, as well as some field surveys.


Program Enhancements


In recent years, the public and users of the FRI have expressed a need for an improved inventory in terms of its ability to provide more timely information, meet the increasing demands of forest management planning, provincial reporting, industry operations, and corporate data management. In response to these needs, the Ontario Ministry of Natural Resources (MNR) announced plans to redesign the FRI program on September 29, 2005. As part of the response, responsibility for the production of the FRI will shift from forest industry to MNR.


The new FRI program will apply to approximately 555,000 km2 of forest land which includes licensed areas, non-licensed areas within designated forest management units, provincial parks, federal parks, and protected areas (see Figure 1).


Planned enhancements to the FRI program include:


  • a move to a ten year re-inventory cycle from a twenty year cycle
  • evolution to a continuous forest inventory from a periodic inventory
  • an improved field sampling component intended to create closer linkages with the Growth and Yield program,
  • provide additional, non-traditional information


The new forest inventory product will be ecologically based and incorporate the use of new interpreting aerial photographs using computer technologytechnologies, data sources, and processes in an effort to achieve higher quality information.
The Inventory, Monitoring, and Assessment Section, responsible for program implementation, is currently confirming business requirements for the new FRI program. This process provides users of the FRI with opportunities to provide input to the development of the new FRI program in order to meet specific business needs.


FRI Production Process


The current FRI production process is a three-year effort involving a number of manual and automated procedures.


First Year:


The primary data source used for the production of the new FRI is digital aerial photography, usually acquired through contracts with private industry.


Digital cameras that capture black and white imagery at 20 centimetre resolution and colour infrared imagery at 40 centimetre resolution are used for data acquisition during summer conditions when trees are in a leaf-out condition.


Potential efficiencies associated with the relatively faster delivery of digital aerial imagery to MNR may allow traditional second year activities to begin in year one, thereby reducing the three year production cycle for an individual forest inventory.


Second Year:


In the second year, photo interpreters determine sample plots on digital aerial imagery and coordinate the collection of field data. The redesigned FRI program will introduce a new series of fixed area plots to the production process. These plots are an addition to the suite of traditional prism/variable plots normally established and measured during inventory production efforts.


As forest stands are delineated, a number of attributes are interpreted including species composition, stand age, stand height, stocking and Forest Ecosystem Classification (FEC) site types. Site class, an indicator of stand growth and productivity, is derived from the relationship between age and height.Data collected by ground crews serves to calibrate the interpretation of forest conditions depicted on aerial photographs.


In addition to field plot data, information supplied by local FRI users is often utilized during the interpretation process and incorporated into the inventory. Although productive forested stands make up the vast majority of the areas inventoried, non-productive and non-forested lands are also delineated, described, and inventoried.


Third Year:


The third year of the FRI production process involves the transfer of boundaries and attribute data from the aerial photographs onto work maps that are based on the Ontario Base Map (OBM) system.


A customized data entry system then validates the information collected as it is transferred to a digital format. Previously constructed work maps are scanned into the system and a number of automated conversion processes are carried out to develop the final product. Information products that can be delivered to clients include:


  • forest stand maps
  • area summary reports
  • forest stand attribute files for both individual maps and entire management units
  • other digital map information.


FRI Planning Cycle


For management purposes, Ontario’s Crown forests are divided into 46 management units. Forest Resource Inventories are required on each management unit about every 10 years. They and must be updated at the start of each new forest management plan (every 10 years) to reflect all changes to the forest. Such changes could include depletions due to harvest or natural reductions, such as those caused by wildfire, insects, disease, and blowdowns. Accruals can also take place as a result of forest renewal and tending activities for both assisted and naturally regenerated areas.


Information generated from forest inventories has contributed greatly to our knowledge of one of Ontario’s renewable resources and continues to serve as the basis for major forest resource planning and policy decisions in the Ontario Ministry of Natural Resources (MNR).


Figure 1 - proposed lands to be inventoried 2006-2016

Figure 1