0640-B1
Mark D. Gillis, Tamara Brierley, Katja Power and Stephen Gray 1
Canada's current National Forest Inventory is a periodic compilation of existing inventory material from across the country. While this approach has many advantages, it lacks information about the nature and rate of changes to the resource, and does not permit projections or forecasts. Being a compilation of inventories undertaken at different dates, the current national forest inventory cannot reflect the current state of the forests and therefore cannot serve as a satisfactory baseline for monitoring change. The current format of Canada's National Forest Inventory has served its purpose by providing national statistical compilations and reporting. To meet new demands, Canada is adopting a new National Forest Inventory design. This consists of a plot-based system of permanent observational units located on a national grid. The objective of the new design is to assess and monitor the extent, state and sustainability of Canada's forests in a timely and accurate manner. Details of Canada's National Forest Inventory are described.
A forest management inventory in Canada is a survey of an area to determine the volume, location, extent, condition, composition, and structure of the forest resource, as well as the way it is changing. It describes the status of the resource, providing a baseline from which to model predictions or to evaluate management prescriptions. The management of Canada's forests is primarily a provincial responsibility. The provinces employ a number of inventory systems, including a reconnaissance inventory, a forest management inventory, and an operational inventory to satisfy the varied needs of forest management.
A forest management inventory is generally static in nature, providing adequate information for extensive management of an abundant resource, but it does not provide sufficient information to satisfy current needs. Changing social values, new government policies, and increased use of inventory data have all increased the need for more accurate, reliable, and timely inventory information. To satisfy these needs, a forest management inventory must present both a static picture of the forests and a dynamic picture of how the forest is changing over time.
The federal government is responsible for the compilation of a National Forest Inventory (NFI).2 To date, the NFI has been based on provincial management inventories. To meet new and evolving information needs, the format of the NFI is changing. Instead of using a periodic compilation of existing inventory information from across the country, a new plot-based system of permanent observational units located on a national grid has been designed.
This paper provides a description of Canada's NFI, outlining how it has evolved into the new plot-based design. The role of the new NFI in a larger forest measurement and forest monitoring system is also discussed.
Canada's National Forest Inventory has continually evolved. Before 1981, the National Forest Inventory was compiled on the basis of questionnaires completed by the provincial and federal forest management agencies. In 1981, a computer-based system was developed to summarize data obtained from management agencies. The Canadian Forest Resource Data System (Bonnor 1982) was developed to store, manipulate, and summarize the basic inventory data.
The approach for the 1981 Canadian National Forest Inventory (CanFI) was to aggregate the best available data from many source inventories, typically provincial/territorial forest management inventories. This approach, described in Lowe et al. 1994, is being used to compile the 2002 version of CanFI. Basically, stand-level data provided by the management agencies are converted to a national classification scheme. The data are then aggregated to the mapsheet, provincial and national levels, for storage, analysis, and reporting. Forest management inventories are the main source of data for the national inventory. Management agencies continually update their inventories; therefore the age of the information is constantly changing. In addition, agencies continually upgrade their forest inventories and introduce new standards, definitions, and measurement protocols to address new information demands. As a result, the national inventory is a snapshot of information collected at different dates and according to different standards.
The 1981 version of CanFI was the first to include maps of the resource, as well as more detailed and accurate tabular summaries. Major developments since 1981 include the following:
The 2002 version of CanFI consists of 32 source inventories and includes a national classification scheme that provides area and volume statistics by land class, ownership and status, site class, age and maturity, forest type, predominant genus, and leading species. Data are summarized to approximately 75 000 inventory units and stored in a relational database management system and a geographic information system (Gillis 2001; Gillis et al. in press). CanFI inventory units are consistent with the boundaries of the provincial inventory mapsheets. These vary in size from the township maps in Alberta (9.7 x 9.7 km) to the 1:50 000 National Topographic Series maps (27.8 x 33.5 km or larger) of some of the older inventories. The entire landbase of Canada is represented in the 2002 version of CanFI; the area of forested land within CanFI units is illustrated in Figure 1.
The national inventory has been used to support a number of applications including: carbon-budget modeling, state-of-the-forest reporting, assesments of the sustainable development of Canada's forests using criteria and indicator processes, and international requirements for forest resources-assessment reporting. Clients have included government science and policy groups, consultants acting on behalf of the different government agencies, universities, students, and the general public.
The current approach of the national inventory is cost effective in that it is based on using existing data. The process is well established and accepted by the contributing agencies. The approach provides detailed information about Canada's forests that is consistent with forest management information. The inventory also contains location-specific information about the characteristics and quantity of the forest resource, thus providing mapping and spatial analysis capabilities.
However, by design, some data in the current inventory could be up to 25 years old, and data standards vary. The current inventory lacks information about the nature and rate of changes to the resource, does not reflect the current state of the forests, and cannot be used as a satisfactory baseline to monitor change. The inventory also generally lacks information about non-timber vegetation attributes and that which exists is of unknown precision.
To address these weaknesses and to meet new demands, the Canadian Forest Inventory Committee (a group of inventory professionals from federal, provincial, and territorial governments, and industry) has developed a new approach for the National Forest Inventory. Instead of undertaking a periodic compilation of existing information from across the country, the Committee decided to use a plot-based system of permanent observational units located on a national grid. The new plot-based National Forest Inventory design (NFI) will collect accurate and timely information about the extent and state of Canada's forests to establish a baseline description of today's forests and to help describe how they are changing over time.
Flexibility was a guiding principle in the development of the new plot-based NFI. Design details should be flexible as long as data consistency can be assured. The same attributes must be measured using the same standards in a statistically defensible manner at an acceptable level of precision. A core design described in A Plot-Based National Forest Inventory for Canada (Natural Resources Canada 1999) has been developed with the following essential elements:
The new inventory will cover all of Canada. All potential sample locations reside on a countrywide 4 x 4-km network. Each province and territory of Canada will decide on a `best design' that will include samples located on a subset of the NFI sample locations or samples selected by a different yet statistically valid design. To provide reliable area statistics, the objective is to survey a minimum of 1% of Canada's land mass. A 1% sample translates into a nominal design of 2 x 2-km photo plots located on a 20 x 20-km network, resulting in approximately 20 000 sample photo plots for Canada. The 2 x 2-km plot will be identified on conventional, mid-scale, aerial photography, and will be delineated and interpreted in full according to land cover classes and other forest stand attributes. Satellite imagery will be used as a surrogate for aerial photography to provide attribute data for areas otherwise not covered by photo or ground plots (e.g., Canada's north). Attributes to be estimated from the interpretation of aerial photographs are listed in Table 1. The flexibility of the design allows the sampling to be more intense to achieve regional objectives, or less intense for non-forested or remote areas, such as Canada's north.
The new NFI design also calls for a minimum of 50 forested ground plots per ecozone. More intensive sampling will be required in some areas to meet regional objectives. There will be no field samples established in the three non-treed, Arctic ecozones. The ground samples will, in most cases, be located at the center point of the photo plot. Approximately 10% of the photo-plot locations will be selected at random for ground sampling. Whenever a random location happens to fall on a non-treed area, a substitute sample location will be chosen, again at random. The initial locations will maintain their status as NFI ground plots, and although no measurements are taken, the locations will be retained in the analysis. Measurements of the ground plots will be synchronized, to the best extent possible, with the interpretation of photo plots. Attributes and data collected in ground plots will complement and enhance the attributes and data from the photo plots. Additional attributes to be measured on the ground are listed in Table 1. The ground plots will also contain information that is not normally collected in forest inventories, such as litter and soil carbon data. Auxiliary NFI attributes (Table 1) will be collected from management records, other data sources, and mapped information.
Remote-sensing data will also be used to enhance the NFI, to assess whether the location of plots are skewed in any fashion, to assess the extent of change and the need to revisit plots, to extend the inventory beyond the 1%, and to provide other area-based parameters such as forest condition. A new project is underway to provide remote-sensing products to assist in the monitoring of the sustainable development of Canada's forests. The project, called Earth Observation for Sustainable Development of Forests3 (EOSD), is designed to provide, at regular intervals, complete (wall-to-wall) satellite coverage of Canada's forested areas. The data will be used to generate the land cover, biomass, and change products required to enhance the plot-based NFI design.
Table 1. Summary of NFI attributes.
The NFI will be on-going. Change will be estimated from repeated sampling of photo and ground plots. The intent is to sample the entire country within the next five years and to spread the re-measurement over a ten-year period covering 10% of the area each year in a statistically defensible manner. Each subsequent re-measurement will be spread over subsequent ten-year periods.
Canada has made a number of commitments to the global community. Canada took a leadership role at the United Nations Conference on Environment and Development (UNCED) in 1992, particularly with respect to forestry and the sustainable management of the resource. A number of initiatives of international significance that followed from UNCEDinclude the Framework Convention on Climate Change, the United Nations Convention on Biological Diversity, and Criteria and Indicators for the Conservation and Sustainable Management of Temperate and Boreal Forests (The Montreal Process).
Over the last decade, in response to international criticism, the federal, provincial, and territorial governments, and industrial agencies have also committed to a number of national initiatives such as Criteria and Indicators of Sustainable Forest Management (The Canadian Council of Forest Ministers 1997), as well as regional criteria and indicator processes and forest certification.
Canada's reporting requirements resulting from these national and international commitments are beyond the capacity of any existing forest inventory or information system. As a result, Canada is developing a next-generation forest measurement and forest monitoring system that can provide timely information for responding, at both the national and international levels, to policy issues related to sustainable development of Canada's forests. The next-generation forest measurement and forest monitoring system (Figure 2) will address key policy issues by identifying and bringing together the best-available geographic information and tabular data.
Recognizing that many complex policy questions cannot be answered by individual scientific studies or single disciplines, many core data sets-such as public inventories (including the new NFI, earth observation from satellite imagery, and other federal and provincial geographic information)-will be integrated using the latest data-handling technologies in a nationally distributed system (e.g., the National Forest Information System4) (Morrison et al. 1999). The data will be available to modelers to conduct analysis and to generate reports. The NFI will provide data for the criteria and indicator processes to monitor sustainable development; to support policy as well as national and international inquiries (e.g., FAO/ECE Forest Resources Assessments); and for reports about climate change. The NFI should also provide a framework for studying the factors affecting forest health and productivity.
Canada's National Forest Inventory is an interagency partnership project. The Canadian Forest Service, under the guidance of the Canadian Forest Inventory Committee (CFIC), coordinates NFI activities. Through the interagency arrangement the provincial and territorial partners develop their designs and provide data. The federal government's role is to develop the standards, procedures, and infrastructure, and to conduct the analysis and reporting.
Since the CFIC meeting in 1997, considerable progress has been made on the development and implementation of the new NFI design. A number of documents have been produced including a design document (Natural Resources Canada 1999) and planning documents examining the approaches, tasks, and costs associated with the implementation of the plot-based NFI. Many jurisdictions have participated in pilot projects that led to a refinement of data standards and procedures. Data standards have been defined, providing the basis for the construction of data models, databases, and supporting data-management tools. The information management systems will be finalized over the next two years with the development of analysis and reporting functions.
The NFI is being implemented through memoranda of understanding between the federal government and the partner provinces or territories. The field implementation has begun in a number of jurisdictions, and agreements are being finalized with the expectation that the remaining jurisdictions will begin implementation this year.
Bonnor, G.M., 1982. Canada's forest inventory. Department of the Environment, Canadian Forest Service, Forestry Statistics and Systems Branch, Chalk River, ON. 79 pp.
Canadian Council of Forest Ministers, 1997. Criteria and indicators of sustainable forest management in Canada. Natural Resources Canada, Canadian Forest Service, Ottawa, ON. Technical Report. 37 pp.
Ecological Stratification Working Group, 1994. Terrestrial ecozones and ecoregions of Canada, 1:7 500 000 scale map. Agriculture and Agri-Food Canada, Research Branch, Centre for Land and Biological Resources Research and Environment Canada, State of the Environment Directorate, Ottawa/Hull.
Gillis, M.D., 2001. Canada's national forest inventory (responding to current information needs). Environmental Monitoring and Assessment 67:121-29.
Gillis, M.D., S.L. Gray, and K. Power, in press. Canada's national forest inventory-what it can tell us about old-growth.
Lowe, J.J., K. Power, and S.L. Gray, 1994. Canada's forest inventory, 1991. Canadian Forest Service, Petawawa National Forestry Institute, Chalk River, ON. 67 pp.
Morrison, R., B. Low, G. Kucera, and H. Kucera, 1999. "A spatial data warehouse for NFIS" pp. 242-247 in Proceedings of the 13th Annual Conference on Geographic Information Systems (GIS 99), March 1-4, 1999, Vancouver, BC. Canadian Forest Service, Pacific Forestry Center, Victoria, BC.
Natural Resources Canada, 1999. A plot-based national forest inventory design for Canada. Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. 70 pp.
Figure 2. Linkage of monitoring systems, data processing, and modeling to information outputs generated from national measurement and monitoring systems.
Figure 1. Area of forest land in Canada (%).
1 Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC, V8Z 1M5, Canada. [email protected]; Website: http://www.pfc.cfs.nrcan.gc.ca/monitoring/inventory/
2 http://www.pfc.cfs.nrcan.gc.ca/monitoring/inventory/
3 www.pfc.cfs.nrcan.gc.ca/eosd/index_e.html
4 See http://www.nfis.org.