The National Forest Inventory

Updated: 30 August 2023

Next update: 30 August 2024

Cubic metres growing stock in Norwegian forests
Cubic metres growing stock in Norwegian forests
2022
998 735
Growing stock and annual increment. Volume inside bark
Growing stock and annual increment. Volume inside bark
2022Change, per cent
1 000 cubic meterShare2021 - 20222013 - 2022
Growing stock
Total998 7351000.39.5
Spruce435 70544-0.29.8
Pine309 364310.79.4
Broad-leaved253 666250.89.3
Annual increment
Total23 995100-0.2-6.3
Spruce12 63653-1.5-6.6
Pine5 481231.2-10.4
Broad-leaved5 878241.3-1.2
Explanation of symbols

Selected tables and charts from this statistics

  • Growing stock inside bark and annual increment inside bark. 1 000 m³
    Growing stock inside bark and annual increment inside bark. 1 000 m³
    Growing stockAnnual increment
    TotalSprucePineBroad-leavedTotalSprucePineBroad-leaved
    2000697 998308 614233 949155 43623 48811 8586 2735 357
    2002685 885306 527228 492150 86623 19712 1355 9525 109
    2003704 487313 979235 030155 47823 99712 6276 0645 306
    2004720 789323 213238 137159 43925 54013 7096 1515 680
    2005735 610331 236241 730162 64425 67413 8686 0925 714
    2006747 945336 201244 622167 12225 52613 7466 0105 769
    2007764 952343 720249 201172 03125 26213 6445 9445 674
    2008783 982352 558254 554176 87024 89713 4825 8575 559
    2009822 569360 501260 521201 54724 83912 9695 7486 122
    2010842 419369 747265 439207 23324 60612 9085 7835 915
    2011877 731379 823273 905224 00324 94213 0305 9785 935
    2012894 133387 844278 516227 77325 27413 2616 0715 942
    2013911 711396 891282 789232 03125 59813 5296 1175 952
    2007-2011929 393407 099286 489235 80425 91213 8216 1155 975
    2008-2012941 659412 984289 685238 68526 12013 9276 0986 095
    2009-2013911 712396 891282 790232 03125 59813 5296 1175 952
    2010-2014929 393407 100286 490235 80425 91113 8216 1155 975
    2011-2015941 659412 984289 685238 98926 12013 9286 0986 095
    2012-2016952 103417 955292 031242 11725 81913 7475 9206 152
    2013-2017964 915424 433296 255244 22925 42113 6355 7196 068
    2014-2018974 453427 798299 754246 90124 90613 3325 5726 003
    2015-2019978 479428 329301 858248 29024 18612 8455 4505 889
    2018-2022998 735435 705309 364253 66623 99412 6365 4815 877
    Explanation of symbols
  • Total area surveyed, by type of vegetation and regions. Km²
    Total area surveyed, by type of vegetation and regions. Km²
    2018-2022
    TotalProductive forest landUnproductive forestBroadleaved bogs and pine bogsSedge and peat bogsOther area
    Appraised regions, total323 77482 50448 4919 04413 850169 885
    Oslo and Viken25 13211 6712 4705147449 733
    Innlandet51 96321 5404 7471 8742 38921 413
    Vestfold og Telemark17 3846 8802 9423686046 590
    Agder16 5346 2633 2923875736 019
    Rogaland, Vestland and Møre og Romsdal57 45210 2937 8547611 40137 143
    Trøndelag - Trööndelage42 11010 9877 1312 3303 96817 694
    Nordland - Nordlánnda38 3166 6286 0148051 24923 620
    Troms og Finnmark - Romsa ja Finnmárku74 8828 24114 0392 0052 92447 673
    Explanation of symbols
  • Productive forest area, by development class. 1 000 hectares and per cent
    Productive forest area, by development class. 1 000 hectares and per cent1
    1 000 hectaresPer cent
    TotalDevelopment class IDevelopment class IIDevelopment class IIIDevelopment class IVDevelopment class VTotalDevelopment class IDevelopment class IIDevelopment class IIIDevelopment class IVDevelopment class V
    2005-20093 519957847597301 151100322212133
    2006-20103 513927797627141 166100322222033
    2007-20113 510777677837021 180100222222034
    2008-20123 507747627877111 174100222222034
    2009-20133 500697457857141 187100221222034
    2010-20143 499597407867181 196100221222134
    2011-20153 483617257867181 193100221232134
    2012-20163 488667117897181 203100220232135
    2013-20173 483706877927331 201100220232135
    2014-20183 473706857807371 202100220222135
    2015-20193 461806737747391 195100219222135
    2016-20203 450846667757401 186100219222134
    2017-20213 444856727517501 186100220222234
    2018-20223 442866837517391 182100320222134
    1Refer to the counties Østfold, Akershus, Oslo, Hedmark, Oppland, Buskerud og Vestfold.These are the only counties that are included in all the inventory cycles presented. As from the inventory cycle 2006-2010, areas above the coniferous forest line are also included.
    Explanation of symbols
  • Growing stock, by type of land, tree species and regions. 1 000 m³ under bark
    Growing stock, by type of land, tree species and regions. 1 000 m³ under bark
    2018-2022
    TotalProductive forest landOther type of land
    TotalSprucePineBroad-leavedTotalSprucePineBroad-leaved
    Total998 735879 280406 516261 036211 728119 45529 18948 32841 938
    Oslo and Viken181 328164 12083 67753 87226 57017 2086 9526 5933 663
    Innlandet246 966227 772120 73375 77331 26719 1947 1036 5025 589
    Vestfold og Telemark105 12591 42543 40626 42321 59613 7004 4905 7383 472
    Agder97 19583 86226 10838 06819 68713 3332 1448 2482 940
    Rogaland, Vestland and Møre og Romsdal142 453124 16139 69240 24544 22418 2928047 9479 540
    Trøndelag - Trööndelage129 912110 82169 69618 50622 61919 0915 4179 0294 645
    Nordland - Nordlánnda54 74744 90520 4383 14921 3189 8422 2782 0595 506
    Troms og Finnmark - Romsa ja Finnmárku41 00932 2142 7665 00024 4478 79502 2126 583
    Explanation of symbols
  • Annual increment under bark , by type of land, tree species and surveyed regions. 1 000 m3
    Annual increment under bark , by type of land, tree species and surveyed regions. 1 000 m3
    2018-2022
    TotalProductive forest areaOther type of land
    TotalSprucePineBroad-leavedTotalSprucePineBroad-leaved
    Total23 99421 80712 1004 7424 9652 187536739912
    Oslo and Viken4 2664 0082 2689997412581118068
    Innlandet6 0885 7423 4331 570739346135101110
    Vestfold og Telemark2 5082 2641 203510551244858575
    Agder1 9971 7607996153472374813951
    Rogaland, Vestland and Møre og Romsdal3 4173 0051 4365421 02741232124257
    Trøndelag - Trööndelage3 4503 1222 15132065132882142103
    Nordland - Nordlánnda1 4461 225680724742214433144
    Troms og Finnmark - Romsa ja Finnmárku822682130115436140036104
    Explanation of symbols
  • Registered incidence of different habitats in productive forest, by region. Per cent
    Registered incidence of different habitats in productive forest, by region. Per cent1
    2018-2022
    Productive forest area below the coniferous forest lineStanding dead treesDead wood lyingTrees with nutrient-rich barkTrees with pendant lichensLate succsessions of deciduousOld treesRich ground vegetation
    The whole country100.02.518.50.32.91.62.63.3
    Oslo and Viken100.02.617.70.03.02.03.13.8
    Innlandet100.01.413.00.05.20.83.31.9
    Vestfold og Telemark100.03.326.80.81.33.64.96.5
    Agder100.04.719.70.30.05.70.41.6
    Rogaland, Vestland and Møre og Romsdal100.03.218.60.50.90.81.33.3
    Trøndelag - Trööndelage100.01.921.10.35.21.73.92.5
    Nordland - Nordlánnda100.01.824.80.62.70.61.35.6
    Troms og Finnmark - Romsa ja Finnmárku100.03.717.80.10.00.00.53.6
    1Corresponds to the registration of habitats for vulnerable and endangered species (red listed species) in ordinaryforest management planning. Two of more habitats may be registered within the same area.
    Explanation of symbols

About the statistics

The statistics provide information on the condition and development of Norway’s forest resources. They give figures on growing stock, annual increments, forest area, age distribution, type of land and tree species.

Last updated: 5 June 2023

Growing stock

Total volume of the standing forest under bark. Comprises trees with a diamter of at least 5 cm at breast height (1.3 metre above ground level).

Annual increment, forest

Annual gross increment in volume in standing forest inside bark.

Development class

Describes the forest's development class from non- regenerated forest to old forest.

Site quality

An expression of the area's capacity to produce wood when stocked with a tree species suitable for the local growing conditions. The site quality of the H40-system is based upon the top height (the average height of the hundred trees per hectare with the largest diameter) of the trees at the age of 40 years at breast height (1.3 m above ground level).

Name: The National Forest Inventory
Topic: Agriculture, forestry, hunting and fishing

30 August 2024

Division for Housing, Property, Spatial and Agricultural Statistics

The results are mainly published at region level.

The results are published yearly. The National Forest Inventory has an inventory cycle of five years. From 1994 the assessment is running. A new result based on the registrations from the last 5 years can always be estimated for the regions and for the country.

International reporting of results from The National Forest Inventory are reported by the The Norwegian Institute of Bioeconomy Reasearch.

Microdata are stored by The National Forest Inventory.

The National Forest Inventory is a sample plot inventory aimed at providing data on natural resources and the environment for forest land in Norway. The Inventory is conducted by the Norwegian Forest and Landscape Institute. Inventory work was started in 1919, with the different inventory cycles taking place in the following years:

1: 1919-30 2: 1937-56 3: 1957-64 4: 1964-76 5: 1980-86 6: 1986-93 7: 1994-98 8: 2000-04 9: 2005-09 10: 2010-2014 11: 2015-2019 12: 2020-2024

As from the inventory cycle 2007-2011 Finnmark county was surveyed for the first time.

Each inventory cycle covers the most important forest districts, while inventories in western and northern Norway have been carried out less frequently and are sometimes incomplete.

The most central users of the results from the National Forest Inventory are public administration at national and county level. The results serve as important input for the formation of forestry policies and control the effects of it.

In recent years, the demand for national forestry statistics has increased, and the National Forest Inventory is a central data source. Data from the inventories are used for example in research to develop descriptive models of forest dynamics.

The forest industry is an important user of the data. Among others thing, they need the data for strategic planning in the sawmill and pulp industry. The data are also used by educational institutions and by professionals in agriculture, forestry and environmental protection.

No external users have access to statistics before they are released at 8 a.m. on ssb.no after at least three months’ advance notice in the release calendar. This is one of the most important principles in Statistics Norway for ensuring the equal treatment of users.

Statistics Norway has estimated the productive forest area in The Sample Surveys of Agriculture and Forestry 2004 and 2008, The Census of Agriculture and Forestry 1979 and 1989. The Farm Register of the Norwegian Agricultural Authority also contains information about productive forest area at property level. Total productive forest area based on the Farm Register is published in the annual structural statsitics of forestry.

The statistics are developed, produced and disseminated pursuant to Act no. 32 of 21 June 2019 relating to official statistics and Statistics Norway (the Statistics Act).

Not relevant

As from the inventory cycle 2007-2011, the statistics include all counties. Finnnmark was surveyed for the first time during the five-year cycle 2007-2011. As from the inventory cycle 2005-2009, areas above the coniferous forest line are also included. Protected or other closed-off areas of productive forest are not included.

The figures are published annually.

The only data source is the National Forest Inventory's database. One of the main tasks of the National Forest Inventory is the assessment of timber resources. Data are collected so that the volume can be computed for different tree species, diameters and quality classes. Numbers of trees and annual increments are also calculated.

The National Forest Inventory's data collection is based on data from permanent sample plots. For the entire country except Finnmark, a systematic sample plot inventory in a bond by 3 x 3 kilometres is established. In the present inventory cycle, sample plots for Finnmark are also established. The plots are visited every five years and the survey forms the basis for statistics for the whole of Norway. In order to publish data by county, temporary plots are established in the counties when each county is appraised. Each county is appraised every fifteen years. An extensive number of attributes concerning forest conditions are recorded on the plots, some of which describe the area. Parameters that characterise level of development and species composition of the vegetation, certain aspects of biodiversity, utilisation and yield capacity of the land, forest treatment, conditions surrounding forest operations, etc., are measured or estimated. Inside a 250 square metre circle, every tree with a diameter of more than five centimetres in breast height (1.3 metres above ground level) is callipered.

The sampling design has changed considerably over the years. The first two cycles were carried out as strip sampling inventories. A system of parallel strips was established throughout the area of interest, and measurements were taken within these strips. In the middle of the 1950s, the strip sampling was replaced by a systematic sample plot inventory, a method which has also been used subsequently. However, minor alterations concerning sampling design have been made several times.

An important difference between the period 1986-1993 and the previous inventory cycles was the introduction of permanent sample plots. A sub-sample of the established plots was marked in order to be able to re-measure the exact same area in future inventories. This was to provide greater possibilities for detecting changes in forest conditions. The permanent plots were re-measured during the period 1994-1998, according to a specific pattern. The inventory of one single year will provide representative results for the whole country.

Highly conspicuous markings are avoided in order to prevent the location of the plots from being too obvious to passers-by. The permanent plots should represent a random sample of the forests in Norway, and should not be treated any different than the rest of the forests. A total of approximately 16 000 permanent sample plots have been established, of which about 10 500 are located on productive forest and other wooded land below the coniferous forest limit. On average, the sampled area comprises about 3 x 10 -5 of the surveyable area.

Before each field season, training is held for the field crew. During the field season, the office staff visit the field workers at least once and some controls are carried out. In most cases, a control of the assessment is done. About 5 per cent of the sample plots are surveyed once more.

Corrections of the field instructions are made before every field season. A main revision is carried out every five years.

In order to estimate figures, for instance for a county, the area factor must be known. In a 3 x 3 kilometre net the area factor will be close to nine square kilometres or 900 hectares. Each sample plot will represent 900 hectares. For each tree measured, a volume with and without bark and the increment are estimated. Multiplying this with the area factor will establish how much each tree represents in this area. The volume for the growing stock in a county for instance can be found by summarising the volume of each measured tree in the county multiplied with the area factor.

Not relevant

Employees of Statistics Norway have a duty of confidentiality.

Statistics Norway does not publish figures if there is a risk of the respondent’s contribution being identified. This means that, as a general rule, figures are not published if fewer than three units form the basis of a cell in a table or if the contribution of one or two respondents constitutes a very large part of the cell total.

Statistics Norway can make exceptions to the general rule if deemed necessary to meet the requirements of the EEA agreement, if the respondent is a public authority, if the respondent has consented to this, or when the information disclosed is openly accessible to the public.

More information can be found on Statistics Norway’s website under Methods in official statistics, in the ‘Confidentiality’ section.

Figures on property level are not published.

The National Forest Inventory carried out the first assessment at county level in 1919.

Systematic errors are caused by errors or uncertainties in measurement, estimation and recording in the field, which are one-sided. Efforts are being made to reduce these errors as far as possible by training the field crews and checking their measurements. An example of errors of this type is the possibility of apparent area changes for productive forest land, which are really caused by different methods of judging the coniferous forest limit. The magnitude of systematic errors cannot normally be calculated.

Random errors of the results are caused by the limited sample of the forest area and wood resources measured by the inventory, in addition to random errors of measurement. A measure for the random error is the so-called standard error, which is possible to calculate. The root mean square error (RMS error) depends on the number of sample plots and the variance of the parameter of interest, for instance volume of growing stock. If the observations are divided into more groups, the magnitude of the RMS error will be higher within each group.

Not relevant

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