Environmental consideration
Here you can find statistics on environmental consideration in regeneration fellings in Sweden. The results are based on inventories of areas subject to regeneration felling, where information on different types of consideration, structures and measures is recorded. The statistics include, among other things, environmental consideration areas, edge zones along water, consideration trees and dead wood, as well as a number of other indicators related to environmental consideration in connection with regeneration felling. Inventories of environmental consideration have been carried out using varying methods since the late 1990’s.
In the most recent results, from felling season 2022/2023, the average share of environmental consideration areas represents 8.5 percent of the area subject to regeneration felling. Just under half of the environmental consideration area consists of areas with a high or very high conservation value, while the remaining parts consists of areas of a more ordinary character. The average width of edge zones along water amounts to 15 metres, and just over 30 percent of the shoreline lacks an edge zone. On average, approximately 10.5 conservation trees are left on the regeneration felling area. The average volume of dead wood left on the regeneration felling area amounts to 7.5 cubic metres per hectare.
Method
The Consideration Monitoring is carried out as a sample survey. From 2025 onwards, results are reported from a newly developed inventory of environmental consideration. The inventory is conducted after regeneration felling, approximately one year after the felling has been completed.
In the new method, data are collected through measurements in sample plots and by delineating consideration areas directly in the field. Edge zones are measured by recording the full extent of the zone as polygons on a map using GPS. This differs from the previous method, which was based on point and transect measurements. The classification of consideration areas into subcategories also differs from previous reporting.
Three-season average
For all results, a mid-year (2022/2023) is stated, referring to a three-season average for the felling seasons 2021/2022–2023/2024.
Consideration area
A consideration area must be located on productive forest land that has reached the minimum age for final felling and must either border on or be surrounded by the felled area.
To be included in the inventory, the area must be at least 100 square metres and no more than 1 hectare. However, consideration areas may exceed 1 hectare if they are elongated and border features such as watercourses, mire edges or steep slopes.
Consideration areas are classified into the categories total edge zone and other consideration. Total edge zone is further divided into edge zones along water and other edge zones.
Total edge zone
Includes edge zones along water as well as other edge zones.
Edge zone along water
Includes edge zones along lakes, seas and watercourses, including ditches (although ditches are not included in the reporting for the period 2021/2022–2023/2024).
Other edge zones
Includes edge zones adjacent to mire impediments, rocky impediments, formally protected areas, areas with high or very high conservation value, and other land-use types or management units.
Other consideration
Includes consideration areas that do not constitute edge zones as defined above.
High or very high conservation value
A consideration area can be classified as having high or very high conservation value. The conservation value of a consideration area is assessed based on a large number of variables collected in the field, such as the number of conservation trees, dead wood, or forest characteristics such as boulder richness or similar features.
Ordinary nature value
A consideration area has ordinary conservation value if it is not classified as having high or very high conservation value according to the above.
Crossing over watercourses
A crossing occurs when a forest machine crosses a watercourse in order to carry out felling or the transport of timber. Crossings may consist of bridges, crossings using laid timber (log crossing), or crossings where machines drive directly over the streambed.
Damage at crossings
Damage at crossings refers to situations where the ground at the entry or exit point (within 3 metres of the shoreline) or the streambed has been affected by machine traffic in such a way that tracks, deposited material or soil disturbance cause, or risk causing, sediment transport, obstruction of water flow, or other negative impacts on the aquatic environment.
Consideration areas
Extent of consideration areas
During regeneration felling, smaller areas are left as consideration areas to preserve natural values and landscape structures. The results show that consideration areas account for an average of 8.5 percent of the area subject to regeneration felling in 2022/2023.
Estimates for the proportion of forest land area left as environmental consideration areas after regeneration felling are available from the Swedish Forestry Agency's inventories from 1999 onwards. Due to changes in inventory methods, the time series is divided into four parts with a 1–2 year gap.
In 2008, the inventory R Polytax were developed into Polytax II and in 2015 the Consideration Monitoring 1.0took over from Polytax II. Between 2019/2020 and 2022/2023, the monitoring system shifted from Consideration Monitoring 1.0to Consideration Monitoring 2.0. The difference in levels between the time series is most likely mainly due to differences in the inventory methods.
The proportion of forest land area left as consideration areas following a regeneration felling is lower for individual owners (6.6. percent) than for other owners (10.7 percent).
The proportion of forest land area left as consideration areas after regeneration felling varies between different felling objects. On 15 percent of the felled area, there are no consideration areas. On 29 percent of the felled area, consideration areas were left on up to 5 percent of the area. On 7 percent of the area of felling, consideration areas amounted to of 20–30 percent whereas on 5 percent of the area of felling, 30 percent or more had been left as consideration areas.
Conservation value of consideration areas
Consideration areas may be left for different purposes and are classified in the statistics both by type of consideration and by conservation value. Across the country, the average proportion of consideration areas amounts to 8.5 percent of the area subject to regeneration felling, of which:
- approximately 2 percent are edge zones along water
- approximately 2.9 percent are edge zones along other landuses such as wetland or unproductive areas
- approximately 3.6 percent are other forms of consideration area
Within all types of consideration areas, almost half of the areas are areas with high or very high conservation values, while the other half are areas with ordinary conservation value. Within sample plots in consideration areas, living and dead trees are registered, and environmental characteristics relating to geology/topography, hydrological influence, cultural influence and natural forest qualities are noted. The data from the sample plots form the basis for statistics on the conservation value of consideration areas.
Results are also presented for selective felling within consideration areas. For 86 percent of the consideration area, the proportion of selective felling is 10 percent or less.
Consideration areas along water in regeneration felling
Edge zones along water
In regeneration fellings next to water, edge zones have been left along just under 70 percent of the shoreline length. This means that just over 30 percent of the shoreline length lacks edge zones. Where an edge zone has been left, the average width is approximately 15 metres. Individual owners have a larger proportion of shoreline without edge zones than other owners, 37 and 25 percent respectively.
Water crossings
In some cases, machinery needs to cross watercourses in order to carry out a felling. Crossings can be undertaken both with and without preventive measures against watercourse damage. These crossings can be constructed and designed in different ways, for example as bridges or crossings with laid timber (log crossing). In cases where no measures have been taken, the machines drive directly over the streambed (streambed crossing). The statistics present both the type of crossing and whether damage to watercourses has been observed.
The results show that streambed crossing is the most common type of crossing with 37 percent, followed by log crossings and bridges, each accounting for approximately one fourth. For a smaller proportion of the crossings, the type could not be determined.
The proportion of observed damage varies between types of crossings. At steam bed crossings where machines drive directly over the streambed, damage occurs in approximately 86 percent of the cases. The corresponding proportion for bridge crossings is approximately 17 percent.
Damage at crossings refers to situations where the ground at the entry or exit point (within 3 metres of the shoreline) or the streambed has been affected by machine traffic in such a way that tracks, deposited material or soil disturbance cause, or risk causing, sediment transport, obstruction of water flow, or other negative impacts on the aquatic environment.
Living trees and dead wood left as consideration on the felled area
In addition to consideration areas, individual trees and dead wood are also retained on the regeneration felling area. The living and dead trees are retained to promote biodiversity and are intended to serve as habitats for other species. The statistics report both the volume and the number of retained trees, logs and snags.
It is important to note that there are breaks in the time series in the statistics on retained trees, logs and snags on regeneration felling areas. These breaks are clearly visible in the figure below. The results are based on inventories carried out at different points in time after regeneration felling: approximately 6–8 years in the first period (2000/2001–2014/2015, data from the Regeneration Survey), approximately 2.5 years in the second period (2017/2018–2019/2020, data from Consideration Monitoring 1.0), and approximately 1.5 years in the third period (2022/2023 onwards, data from Consideration Monitoring 2.0). In addition, the inventory method was changed from transects in the first period to sample plots in the later periods. The results are therefore not fully comparable between periods, which primarily affects the reporting of consideration trees and logs.
For example, an increased volume per hectare of seed trees may be due to the inventory being conducted closer to the time of felling than in earlier inventories. This may also apply to logs, where the change in method from transects to sample plots may also affect volume per hectare. Due to the existing breaks in the time series, no statistically significant increase can be established.
In total, individual owners leave a larger volume of trees per hectare for trees, logs and snags on the regeneration felling area then other owners. The difference mainly consists of a greater use of seed and shelter trees by individual owners.
The dead wood left on felled areas consists of standing dead trees, logs and snags (both natural and artificial snags). On average, 7.5 cubic metres of dead wood are left per hectare, of which just over two thirds is hard dead wood. On average there are 30 individual dead wood substrates, per hectare.
On average, 10.5 conservation trees per hectare are left on the regeneration felling area. Individual owners leave 11.7 conservation trees per hectare while other owners leave 10.5 trees per hectare. On average, 1.3 trees per hectare with a diameter of at least 45 cm are left. There are differences between ownership classes and individual owners leave 1.8 trees per hectare and other owners leave 0.7 trees per hectare larger than 45 cm.
The most common tree species among the conservation trees are Scots pine and birch.
Size of contiguous bare forest land
Fellings that, within a period of three felling seasons from the time of felling, are located less than 20 metres from each other are, in this context, considered to form a contiguous bare forest land. This is regardless of whether they extend across property boundaries or were felled at different times, provided that this occurred within the specified time interval.
In Sweden, the average size of contiguous areas was 4.5 hectares and the median size is 2.5 hectares for 2023. The 95th percentile (the five percent largest contiguous areas) was 15.1 hectares or larger. The median size was 4.3 hectares in Northern Norrland, which is the region with the largest contiguous bare forest land. The size decreases further south in the country, with a median size of 1.9 hectares in Götaland.
The county with the largest contiguous areas is Norrbotten, where the largest five percent of bare forest land areas are 27.8 hectares or larger. Kronoberg County has the smallest areas of contiguous bare forest land, where the largest five percent are 6.5 hectares or larger.
From 2013 onwards, a slightly decreasing trend can be observed in the size of contiguous bare forest land areas in the 95th percentile. A break in this trend can be seen from 2018 onwards. Changes in the size of contiguous bare forest land areas are observable in the 95th percentile, while neither the mean nor the median shows any clear trend over the period (Figure 9).