The area in each primary sampling unit available for timber harvest should be available by querying existing forest management records. The complete landuse classification of all primary sampling units will provide a national figure for permanent forest loss. At the first assessment, historic material must be incorporated to distinguish changes during the last 10 years prior to classification. The NFI survey will provide unbiased estimates of the area visibly affected by insects. It does not provide the area of a given attack.
Severity is classified into broad categories from mild to severe.
No positive identification of causing agent will be made. Area and severity of visible disease infestation see 17 19. Area and severity of visible fire damage see 17 20. Total biomass by forest type, age, succession stage Photo plots provide only indirect measures based on model predictions. Ground plots will sample biomass, but samples will be small and the within-plot error will be large.