National Forest Inventory
The National Forest Inventory (NFI) conducts a systematic sample-based survey of the Norwegian forest, providing vital resource and environmental data for the whole of Norway as well as for regions. It records variables that provide information about growing stock and annual increment, operating conditions and environmental conditions. The content of the inventory is regularly updated to meet new demands from the society.
The Norwegian NFI started in 1919, and the establishment was triggered by concern and uncertainty about the conditions of our forests. Norway was the first country in the world to start a systematic inventory of its forests to ensure sustainable forest management.
What is the main use of the NFI data?
The data from the NFI forms part of Norway's official statistics. Its most important users are:
- The public administration at both national and regional level. The data and results provide a basis for developing forest policies and monitoring the effects of policy measures.
- The forest industry, which uses the information for strategic planning as regards bio-energy, wood processing and the sawmill industry.
- Researchers, who use NFI data to increase knowledge of forest dynamics. The data form the basis for the development of e.g. prediction models for various purposes.
- National reporting. The NFI produces miscellaneous statistics about the Norwegian forests, including basic forest statistics reported by Statistics Norway.
- International reporting. We report miscellaneous forest information, including indicators for sustainable forestry, to the Food and Agricultural Organization of the United Nations (FAO), the United Nations Economic Commission for Europe (UNECE) and Forest Europe.
- The Norwegian Environment Agency which, according to the UN Framework Convention on Climate Change, reports statistics on uptake and emissions of greenhouse gases from the forest. Figures for emissions or sequestration of greenhouse gases from land use and land use changes are also included in the report.
The inventory is carried out as a systematic sample. Each sample plot is 250 m2 and located at the intersections of 3 x 3 km grid, except for areas above the coniferous tree line and in the northernmost county (Finnmark), where the grid is sparser (3 x 9 and 9 x 9 km, respectively). In total, there are approximately 22,000 sample plots, of which ca. 12,000 are in forests. The inventory is conducted by a staff of approximately 25 field workers, and each plot is re-measured regularly according to a five-year rotation. This means that one fifth of the plots are measured per year and it takes five years to collect data from all plots. The entire country is however included in each year’s selection of plots, making it possible to obtain updated forest statistics for the entire country on a yearly basis.
Monitoring and development
Monitoring of forest conditions is an important function of the inventory, and involves:
- Monitoring the effect of forest policy measures, for example the felling and re-establishment of forests, and the availability of timber resources.
- Monitoring carbon stores in forests to report on emissions and sequestration of greenhouse gases from forests, forestry and land use changes.
- Monitoring forest damage through the recording of various diseases and damages to individual trees and forest stands.