About inventory and analysis

Three inventory levels of detail are used by forest managers in the Northwest Territories (NWT). These are reconnaissance, management and operational inventories.

The level of inventory required within an area is determined by the various capabilities of the forest resource, the level of use of the forest resource and the types of decisions related to the use of the forest vegetation. All these criteria must be balanced with the high cost of inventory work when considering the level of inventory required.

Levels of inventory are evolving to more effectively achieve data collection goals for the NWT and to better address a full range of values related to sustainable management. Additional attributes are being collected to provide information for non-timber values such as wildlife habitat and rare plant species. New approaches to inventory updates are being implemented to provide data on sustainable forests and changes to the resource over time. Alternative approaches to data collection are also being researched to identify more cost effective options.

A satellite based reconnaissance inventory has been completed for the entire NWT and a partnership established with Natural Resources Canada for inventory update. More detailed inventory at the management level, about 40,000 km², has been completed in the Mackenzie Valley, Dehcho and South Slave regions.

A detailed inventory project takes three to five years to complete and priority areas are identified. Many productive forest areas have been inventoried but large areas still require detailed forest inventory work to ensure sustainable use of forest resources.

Reconnaissance inventory

A broad land cover classification using Landsat TM5 and TM7A broad land cover classification using Landsat TM5 and TM7 satellite imagery has been developed and completed for all forested lands in the NWT. Information is developed using satellite imagery and a field program. This new approach to forest inventory allows for the collection of data on large areas where it was not economically feasible to carry out inventory work previously.

This work has resulted in the development of a NWT lands area poster for large format printing a NWT land areas map and, a NWT EOSD vegetation classification map.  These tools assist in strategic planning in forest fire management, wildlife management and to determine priority areas for more detailed inventories.

Management inventory

Management level inventories are detailed forest vegetation inventories of an area.  They provide information for resource and land use planning that can be used for timber supply analysis and to guide forest development activities. This level of inventory is generally carried out on areas where the capacity to produce timber for commercial or local use exists, where development concerns must be addressed at a more detailed level or where there is a need for more detailed information on forest vegetation for other purposes.

Two scales of aerial photography are being used in the NWT management inventory program: 1:20:000 and 1:40:000. The inventory involves the acquisition of aerial photography, photo interpretation, data transfer into a Geographic Information System (GIS) and ground sampling. Most of the potentially commercial forest in the NWT has been inventoried at the 1:20:000 scale.

Operational inventory

An operation inventory is usually carried out when a permit or license for timber harvesting is requested. It provides detailed stand level information including a volume assessment and verifies information provided from management inventories or provides stand level information if no management inventory exists.

An operational inventory usually consists of compiling existing maps, reports and field data to approximate the amount of volume available in an area of interest. A detailed field survey is then be carried out to gain specific information on the targeted stands.

Volume sampling

Ground sampling programs always accompany a management level inventory and may also be carried out on reconnaissance or operational inventories. They are conducted to provide additional information not available from aerial photography, most importantly volume. Temporary sample plots are established in the field and the data are used to provide information on a wide range of attributes including trees, ecology, site and soils.