National Forest Inventory
The National Forest Inventory (NFI) provides information on the condition and development of Norway’s forest resources, based on a nation-wide survey of permanent sample plots visited every five years.
The data serves as an important basis for national forest policy development, and for fulfilling Norway’s commitments to international reporting within the Kyoto an UNFCC framework. High-quality data on the forest resources and the condition of the forest based on long time-series are also vital to sustainable forest management, and represents a unique data source for a wide suite of research purposes.
Norway’s NFI was established in 1919. Since then, the vast majority of the country has been covered ten times, and we are now (2015) starting on the 11th inventory cycle. The NFI is a representative sample-based survey, which apart from the field-based assessment of forest resources also yields a classification of the Norwegian mainland with respect to land types and land use, including non-forest land. The data and statistics are used by both Governmental bodies and other public administration, as well as by the forest industry. The data is also widely used for research and teaching purposes.
The inventory scheme is based on a network of permanent plots, distributed in a grid across all of Norway. The plots are assessed on a five-year rotation basis. On plots located on forest land or other land types with tree cover, all trees growing within a 250 m² plot are measured with their coordinates included, thus enabling time-series to be established at the tree level. In addition to stand volume, increment and tree species, a range of parameters are measured to provide information about e.g. site productivity, stand structure, forest health, forest operation conditions, and biological diversity.
Different remote sensing platforms are increasingly used to provide information about the forest resources, both in Norway and internationally. Development and testing of remote sensing applications is thus an important field of research within the NFI.