Increment and drain of growing stock
|Updated: 1.12.2017 - Next update: 2.10.2018|
Timber reserves increasing each year
Over the past 50 years, the timber reserves in forests have increased annually. According to data on timber reserves from the 12th National Forest Inventory (NFI12), the growing stock volume in forest land and forest land of low productivity is 2,464 million cubic metres. Compared with the previous inventory, the volume has grown by five per cent. The annual increase in the growing stock volume in forest land and forest land of low productivity totals 110 million cubic metres with a four per cent growth from the previous inventory. Average growth per hectare in the whole country was 4.8 cubic metres.
The annual growing stock volume started growing strongly in the 1970s, prior to that it had remained slightly below 60 million cubic metres for two decades. The increase in growth has been mostly affected by peatland drainage, improved forestry and the age structure of forests becoming more even. The area of forests with limited standing timber has also decreased.
The main trend in the drain of Finland’s growing stock has also been upwards. In 2016, the drain reached a new high of nearly 86 million cubic metres. In 2000 to 2015, the average drain of the growing stock was 71 million cubic metres of which the share of private forests was 83 per cent. The forest industry has cut the production capacity of the paper industry, in particular, but at the same time, the use of energy wood in heating and power plants has increased.
Natural Resources Institute Finland
Description of indicator
Comparison of the growing stock increment and drain (forest balance) shows whether the stemwood stock in forests is growing, remaining unchanged or decreasing. The volume is expressed as million solid cubic metres with bark.
The latest data on growing stock increment are based on the National Forest Inventory (NFI12, years of measuring 2014 to 2016), performed by the Natural Resources Institute Finland. The Finnish Forest Research Institute started the National Forest Inventory already at the beginning of the 1920s. The NFI data are sample data that cover the entire country. According to the current system, one inventory measures nearly 60,000 sample plots and 500,000 trees on forest land over a five-year period.
The estimate of the growing stock drain is based on wood consumption studies until 1984 and after that on annual wood consumption and felling statistics. In addition to felled stemwood, the growing stock drain also includes stemwood waste left in forests and naturally died stemwood.