Knowledge of forest biomass is necessary for reporting on the state of Canada's forests. It is also an indicator of carbon that enables insights on the interaction between forests and the atmosphere. Forest biomass information has largely been aspatial and derived using plot estimates from Canada's National Forest Inventory. Provincial and territorial governments and private industrial organizations have broadened the diversity of information needs and demand for methods that are more spatially explicit. These realities have resulted in a variety of data sources nested within four approaches that can be applied from local to national scales. Earth observation data contribute to each of these approaches to varying degrees and not all approaches result in large area biomass maps. This paper describes the approaches for biomass mapping in Canada, their synergism, and highlights their dynamic nature as new data sources and ongoing developments will continue to refine these approaches to estimate, map, and monitor forest biomass in Canada.

Knowledge of forest biomass is necessary for reporting on the state of Canada’s forests. Biomass information is also required for ecosystem productivity and carbon budget models, and it serves as an indicator of the structural and functional attributes of forest ecosystems. Forest biomass information used in national reporting is mostly derived from regional and national estimates of forest biomass from Canada’s National Forest Inventory (NFI), and subsequent mapping of biomass using compiled NFI inventory data. Extending inventory data into maps of forest biomass, however, can be a challenging exercise that is influenced by a multitude of factors related to data availability and the scaling of tree-level allometric functions to the stand level. The spatial extent of existing forest inventories results in data gaps when regional or national biomass estimates are of interest, and this is a particular problem in the northern areas of Canada where access and resource requirements preclude the creation of large area inventories. As a result, there is a requirement to incorporate some level of remote sensing information from which biomass can be modeled and mapped. There are at least four different approaches that comprise recent, current and proposed biomass estimation and mapping activities in Canada. Earth observation data contribute to each of these approaches to varying degrees and while not all approaches result in large area biomass maps, they all provide a means of generating estimates for large regions. These four approaches for estimating and mapping biomass include: 1. Inventory Compilation, Estimation and Mapping: The historical approach involves a compilation of provincial forest inventories and was used to produce the first national forest biomass inventory in Canada. This approach has subsequently been replaced by the NFI, a plot-based system consisting of a 2 km by 2 km sample plot distributed 20 km apart in a systematic grid network across the country. Inventory data at NFI plots are now

Information needs associated with forest management and reporting requires data with a steadily increasing level of detail and temporal frequency. Remote sensing satellites commonly used for forest monitoring (eg, Landsat, SPOT) typically collect imagery with sufficient temporal frequency, but lack the requisite spatial and categorical detail for some forest inventory information needs. Aerial photography remains a principal data source for forest inventory; however, information extraction is primarily accomplished through manual processes. The spatial, categorical, and temporal information requirements of large-area forest inventories can be met through sample-based data collection. Opportunities exist for very high spatial resolution (VHSR; ie, <1 m) remotely sensed imagery to augment traditional data sources for large-area, sample-based forest inventories, especially for inventory update. In this paper, we synthesize the state-of-the-art in the use of VHSR remotely sensed imagery for forest inventory and monitoring. Based upon this review, we develop a framework for updating a sample-based, large-area forest inventory that incorporates VHSR imagery. Using the information needs of the Canadian National Forest Inventory (NFI) for context, we demonstrate the potential capabilities of VHSR imagery in four phases of the forest inventory update process: stand delineation, automated attribution, manual interpretation, and indirect attribute modelling. Although designed to support the information needs of the Canadian NFI, the framework presented herein could be adapted to support other sample-based, large-area forest monitoring initiatives.

Many countries undertake a national forest inventory to enable statistically valid monitoring in support of national and international reporting of forest conditions and change. Canada's National Forest Inventory (NFI) program is designed to operate on a 10-year remeasurement cycle, with an interim report produced at the 5-year mid-point. The NFI is a sample-based inventory, with approximately 18,850 2×2-km photo plots across the country, distributed on a 20×20-km grid of sample points; these photo plots are the primary data source for the NFI. Capacity to provide annual monitoring information is required to keep policy and decision makers apprised of current forest conditions. In this study, we implemented a multistage monitoring framework and used a Moderate Resolution Imaging Spectroradiometer (MODIS) change product to successfully identify 78% of the changes in forest cover area that were captured with a Landsat change detection approach. Of the NFI photo plots that were identified by both the Landsat and MODIS approaches as having changes in forest cover, the proportion of change area within the plots was similar (R2=0.78). Approximately 70% of the Landsat-derived change events occupied less than 40% of a single MODIS pixel, and more than 90% of the change events of this size were successfully detected with the MODIS product. Finally, MODIS estimates of the proportion of forest cover change at the NFI photo plot level were comparable to change estimates for the ecoregions as a whole (R2=0.95). High-temporal, low-spatial resolution imagery such as MODIS, in combination with other remotely sensed data sources, can provide information on disturbance events within a national forest inventory remeasurement cycle, thereby satisfying the interim information needs of policy and decision makers as well as the requirements of national and international reporting commitments.

A new national forest inventory is being installed in Canada. For the last 20 years, Canada's forest inventory has been a compilation of inventory data from across the country. Although this method has a number of advantages, it lacks information about the nature and rate of changes to the resource, and does not permit projections or forecasts. To address these limitations a new National Forest Inventory (NFI) was developed to monitor Canada's progress in meeting a commitment towards sustainable forest management, and to satisfy requirements for national and international reporting. The purpose of the new inventory is to "assess and monitor the extent, state and sustainable development of Canada's forests in a timely and accurate manner." The NFI consists of a plot-based system of permanent observational units located on a national grid. A combination of ground plot, photo plot and remote sensing data are used to capture a set of basic attributes that are used to derive indicators of sustainability. To meet the monitoring needs a re-measurement strategy and framework to guide the development of change estimation procedures has been worked out. A plan for implementation has been drafted. The proposed plan is presented and discussed in this paper. Key words: Canada, forest cover, inventory, monitoring, National Forest Inventory, re-measurement, panel

Canada is the steward of some 10% of the world’s forests. Forestry is also the single largest industry in Canada’s economy. The demand for verifiable, current, and credible information on a range of forest indicators is growing as the forests’ ecological, economic, and social functions are increasingly appreciated. To meet this demand for information, Canada is implementing, in co-operation with provincial and territorial resource management agencies, a new National Forest Inventory and a satellite-based forest mapping and monitoring program. The new plot-based forest inventory will provide a statistically valid estimate of the current forest conditions and their changes over time. The satellite-based forest cover information will be used to extend and update some of the inventory attributes. These programs are designed to address various current and future information and reporting needs. One specific application described here is the National Forest Carbon Accounting Framework. It combines data from these (and other) sources to estimate forest carbon stocks and stock changes. Information from these three integrated national programs will support international reporting requirements and will assist in the development of policies aimed at the sustainable development of Canada’s forest resources.

Canada's National Forest Inventory is a periodic compilation of existing inventory information from across the country. The main sources of information are detailed, stand-level descriptions contained in provincial, territorial, and industrial management-level inventories. Typical management inventories do not identify old growth as a specific attribute. Therefore, the National Forest Inventory, based on management-level inventories, does not specifically show old growth. Indicators of old growth, such as stand age and maturity, are contained in the national inventory and are analysed to illustrate the distribution of forest in Canada by age and maturity. A further analysis by selected species is also provided. Finally, a new plot-based national inventory that will provide additional old-growth indicators is discussed. Key words: forest inventory, inventory attributes, old growth, old-growth indicators, NFI, CanFI, EOSD

Canada requires a next generation forest measuring and monitoring system that responds to key policy drivers related to climate change and to report upon sustainable forest development of Canada's forest both nationally and internationally. The Canadian Forest Service, in partnership with the Canadian Space Agency, is using space-based Earth observation (EO) technologies to create products for forest inventory, forest carbon accounting, monitoring sustainable development, and landscape management. The Earth Observation for Sustainable Development of Forests (EOSD) initiative will work in partnership with the Provinces and Territories and develop a land cover map of the forested area of Canada. Research programs are also a component of EOSD to develop techniques for change monitoring, biomass estimates and automated processing to aid in production. Inputs from EOSD will be an important data source in the National Forest Carbon Accounting Framework and will also be used to enhance Canada's new plot-based National Forest Inventory. Initially EOSD, working with the provinces, territories, universities and industry, will work to develop a national map of the forested land cover of Canada with the long term goal of producing not only land cover maps, but maps of forest change over time, and biomass. The National Forest Information System will be used to integrate and synthesize applicable data and products and make them accessible to a wide range of users through the web.

Deforestation is a persistently important issue locally, nationally, and internationally. It is of interest to the public, foresters, environmental organizations, and governments, yet it is difficult to obtain reliable estimates of its extent and nature. Climate change and the role of forests has given a large impetus for formalizing reporting on deforestation. Under the proposed Kyoto Protocol, industrialized nations are required to report on the carbon consequences of deforestation and include them in their greenhouse gas emissions accounting. Canada must develop measurement systems to report on the area of deforestation and the carbon stock loss. Possible data sources include the new plot-based National Forest Inventory (NFI), land use records, and satellite remote sensing. The NFI is a network of 2 x 2 km plots at a 20 km spacing for which land cover and stand attributes are interpreted from medium-scale aerial photography. In this study, medium-resolution satellite imagery, such as Landsat Thematic Mapper (TM), was explored as a potential tool for deforestation estimation and a survey of available land use records was conducted. Factors affecting the utility of each data source and various system design options were examined. An integrated system is suggested that utilizes the NFI as a base, augmented by satellite remote sensing plots and supported by local records as appropriate.

Canada's current National Forest Inventory is a periodic compilation of existing inventory material from across the country. While the current approach has many advantages, it lacks information on the nature and rate of changes to the resource, and does not permit projections or forecasts. Being a compilation of inventories of different dates, the current national forest inventory cannot reflect the current state of the forests and therefore cannot be used 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. However, its useful life is coming to a conclusion. To meet new demands, Canada is considering a new National Forest Inventory design consisting of a plot-based system of permanent observational units located on a national grid. The objective of the new inventory design is to assess and monitor the extent, state and sustainability of Canada's forests in a timely and accurate manner. Details of the new inventory design are described. A strategy to respond to Canada's national and international forest reporting commitments through a National Forest Information System is also discussed.

Aerial photointerpretation is the mainstay of management forest inventories. Accuracy and consistency of this interpretation is a major concern. In addition there is a growing demand for these inventories to provide more quantitative information and data on new forest parameters. Incorporation of computer-assisted techniques to the interpretation process offers potential to improve forest inventories along these fronts.Techniques must fit into the current infrastructure of mainly small or independent interpreter groups or individuals using 1:10 000 to 1:20 000 scale stereo photography. Computer-assisted interpretation therefore must be based on digitized photography and not necessitate large computers or costly display systems or analysis software. They must be simple to apply and not require inordinate fine tuning or trial and error by the interpreter.Envisaged techniques are: 1) computer-based interpretation keys, 2) recall acid display of ancillary data, 3) computer-assisted interpretation review where interpreters can quickly compare all stands they have interpreted as a given stand type, 4) automated single tree analysis including automated single tree isolation, delineation and species classification, plus estimations of stems/ha, crown closure, crown size, numbers of snags, and gap or patch size distribution, and 5) pixel and area based features such as conventional pixel classification and various texture measures for stands that could be presented visually or numerically to the interpreter as an aid. As well, visual or parametric comparison of current and past inventory photography presents a vast array of possible benefits to interpretation.

Modern forest management presents ever increasing demands for accurate and up-to-date forest inventory information. The process of inventory update is critical. Inventory update in Canada is examined including update for harvest, burns, insect and disease, silviculture, roads and other changes. The magnitude and requirements of the update task are documented. The procedures used are described and summarized by province in table form. Usage, advantages and disadvantages of current methods (e.g. conventional 9 × 9 aerial photography, supplemental aerial photography, satellite imagery, and aerial reconnaissance) are examined, new methods discussed and trends highlighted. Also outlined are issues related to the incorporation of silviculture and insect and disease information into inventories and the structure and responsibilities for update. Key words: forest inventory, inventory update, harvest, burns, insect and disease, blowdown, silviculture, aerial photography, satellite imagery, Global Positioning System, aerial reconnaissance, video

Forest inventory procedures are likely to change or evolve at a more rapid rate over the next 15 years. Changes will be brought by changing forest management practices and priorities, increasing importance of environmental and multiple use issues, new technologies, increasing participation of industry, new market forces, and budgetary considerations.Map production is a major and costly component of forest inventory and one which will be much affected by these changes. This paper focuses on the map production component of forest inventory in Canada, but places it in the context of overall management inventory production. Inventory mapping procedures from provincial inventory cycles are summarized. The costs, time, and resources expended on each component of map production (photo acquisition, interpretation, transfer and drafting, and digitizing) are outlined. They are summarized in the context of the cost and resources needed for the total inventory process including volume sampling. Recent innovations, forces causing changes and rethinking of inventory philosophies, and future trends are discussed. Key words: forest inventory, GIS, map production, photo interpretation