Sharp decline in forest fertilisation in 2022

Nyhet | Statistik - 05 September 2023

Fertilisation of forest land fell by 77% between 2021 and 2022, according to the Swedish Forest Agency's silvicultural survey. Fertilisation has not been this low since the introduction of nitrogen fertilisation on forest land in the 1960s. The decline was caused by high fertiliser prices due to the war in Ukraine.

In 2022, 9 900 hectares of productive forest land were fertilised in Sweden. This was a decrease of 77% compared to the previous year, when 42 700 hectares were fertilised. It is the lowest level of fertilisation since 1963, when nitrogen fertilisation of forest land had just been introduced. The area of productive forest land fertilised has fluctuated over the previous 20 years, with a low of 13 800 ha in 2002 and a high of 80 400 ha in 2010. The decrease between 2021 and 2022 was caused by the sharp increase in fertiliser prices in 2022 due to the war in Ukraine. The import price index for fertilisers and nitrogen products increased by 100% in the same year, while the producer price index increased by 38%.

High level of felling leads to more regeneration

The high felling rate in recent years combined with the low use of natural regeneration as a regeneration method, continues to have an impact on regrowth measures which have increased or remained at high levels. In 2022, scarification was used on 197 500 hectares and 214 400 hectares were planted. This compares to an average of 170 400 hectares scarification and 175 100 ha planted per year over the last 10 years.

The Swedish Forestry Agency has undertaken surveys of silviculture since 1955. Artificial regeneration is a collective term for both planting and sowing. In 2022, 223 600 hectares of productive forest land were artificially regenerated, which is on a par with both 2021 and 2020. Over the past three years, forest cultivation has been at the highest levels seen in the Swedish Forest Agency's annual survey.

Supplementary planting returns to normal levels

After the dry summer of 2018, 58 million supplementary plants were planted in 2019. Before that, 20 to 36 million supplementary plants had been used per year since 2005. Since 2019, supplementary planting has gradually decreased and in 2022, 39 million plants were planted.

Non-clearcut forestry

Since 2020 the Swedish Forest Agency has estimated the extent of non-clearcut forest management in Sweden. Non-clearcut forestry is defined in the survey as forestry managed so that there is a continues tree cover without any larger patches of clearcuts.

In 2022, non-clearcut forestry covered 720 000 hectares in Sweden, about 3 per cent of the productive forest land, which is at the same level as the previous year. The estimate has a margin of error that gives a confidence interval from 608 000 hectares to 832 000 hectares. This refers to a 95 per cent confidence interval and is described in the explanation of the statistics below. The majority of non-clearcut forestry, about 512 000 hectares, was managed by individual owners and about 208 000 hectares was managed by other owners.

Explanations regarding the statistics

The statistics from the Swedish Forest Agency regarding silvicultural activities are based on two surveys: one random sample survey of small-scale forestry (owners of less than 5 000 hectares of forest land) and a total population survey of large-scale forestry (owning more than 5 000 hectares). The survey of the large-scale forestry consists of more questions which is why for example the Pinus contorta regeneration is only known for this group.

All estimates presented here have a statistical margin of error. The interval formed by the estimate and the margin of error is a 95% confidence interval. This means that if one were to repeat the survey, it would in 19 cases out of 20 cover the true (but unknown) value. The size of the interval depends on the number of observations in the sample and how widespread the variable is. The margins of error are usually not written in text but are available in the Swedish Forest Agency's statistics database together with the estimates. It has been included in the text above regarding clear-cutting forestry as variable has been surveyed a limited number of times which results in an increased uncertainty.