According to Swedish official statistics the total annual increment in Sweden is 123 million forest cubic metres per year in the most recent estimate, compared to almost 130 million forest cubic metres per year estimated five years ago.
– This trend needs to be analysed further, but can likely be attributed to many coinciding factors, such as harvesting levels, forest management, weather conditions and damages, says Jonas Fridman, Program Manager of the Swedish National Forest Inventory (NFI), SLU, Umeå.
The National Forest Agency publishes gross felling statistics annually, and estimates of felling's exceeding 90 million forest cubic metres per year have been recorded at the same time as the annual natural loss (trees die for other reasons than felling, i.e. wind throw) according to the NFI has contributed to add almost another 14 million forest cubic metres per year to the total drain. Omitting an exceptional storm in 2005 the total drain has never been higher for an individual five-year-period.
Forest available for wood supply is decreasing
An analysis of productive forest lands in Sweden since the 1950ies until today, shows that the area of productive forest land which is available for wood supply has decreased and that protected areas for nature conservation have increased substantially during the same period.
– In addition to the decrease in annual increment this contributes to decreasing harvesting potential in forestry if sustained standing volume is a priority, notes Jonas Fridman.
Theme section on dead wood
This year's theme section is entitled The dead wood, and presents results on measurements and assessments of deadwood on NFI field plots. Dead wood is of great importance to biodiversity.
– The amount of hard dead wood has more than doubled since 1926, says Cornelia Roberge, analyst at the NFI. The total volume of dead wood on forest land is 244 million m3 today, which corresponds to 8.9 m3 per hectare. The amount of dead wood within formally protected areas is 20.4 m3/ha, compared to 7.9 m3/ha outside.
For decomposed dead wood there are no data for comparisons over the same time period.