Karin Bergqvist

Woodpeckers are known as the construction workers of the forest

By: 
Karin Bergqvist

There are good reasons to listen out for drumming in our boreal and temperate forests, because the number of woodpeckers tells us something about the health of forest ecosystems.

One February day, over 30 years ago, I saw a white-backed woodpecker in real life for the first, and so far only time. It was perched high up in a tree. Its rapid, drum-like call lasted up to two seconds. Every now and then it pecked at the trunk. If it had been in Norway or the Baltic States, it might not have seemed so remarkable. But this was in Sweden, where forestry, with its clear-cutting and spruce plantations, had hit the species hard. There weren’t many white-backed woodpeckers left.

Naturally I had heard drumming in the forest and pecking from trees before, usually from the great spotted woodpecker, a relative of the white-backed. Drumming and pecking sounds are intimately associated with woodpeckers and can be heard in many parts of the world. There are around 240 species in the woodpecker family, Picidae, of which around 210 are in the subfamily Picinae – the true woodpeckers. Tropical forests harbour most species, but woodpeckers are found all the way up in the northern taiga. They have strong beaks that are used for drumming, pecking out nest holes and foraging. Many species peck holes in tree trunks and then use their long tongues to extract insects and larvae. Drumming is the “call” that woodpeckers use to mark their territory and attract a nesting partner.

There are good reasons to listen out for drumming in our boreal and temperate forests. Not just for the sake of woodpeckers, but because the number of woodpeckers tells us something about the health of other species. This is because many woodpeckers are sensitive to changes in the environment, especially because they depend on trees, often dead or dying trees. Woodpeckers are known as the construction workers of the forest. They create nests for other species and are therefore keystone species. These species have a disproportionate impact on an ecosystem in relation to their abundance or biomass.

Ecosystem engineers are keystone species that create or influence the habitats of other species. Woodpeckers peck out their own nests and thus act as ecosystem engineers. Once they have finished nesting and abandoned their holes, other species move in or use them for roosting. In northern Europe, for example, the black woodpecker’s nest hole can be reused by goosander, smew, goldeneye, stock dove, owls, jackdaw, starling, pine marten, red squirrel and bats (1). In the coniferous forests of western North America, 20 to 30 similar bird and mammal species have been reported to use nest holes or other cavities made by the pileated woodpecker (2). Examples include several owl species, the American marten, fisher bat and silver-haired bat.

Woodpeckers build fewer holes in intensively managed forests. This has been shown by a study based on inventories carried out over a period of 37 years (1986–2022) in 56 forest stands in southern Finland (3). The spruce-dominated forests consisted of coniferous and mixed forests. The nests were made by six species of woodpecker and two species of tit. The woodpecker species were black woodpecker (Dryocopus martius), great spotted woodpecker (Dendrocopos major), lesser spotted woodpecker (D. minor), white-backed woodpecker (D. leucotos), three-toed woodpecker (Picoides tridactylus) and grey-headed woodpecker (Picus canus).

The forest was divided into three groups: managed forest (based on clear-cutting, planting and repeated thinning), natural forest (largely protected forest with no signs of having been clear-cut and basically unmanaged since the early 1950s) and semi-natural forest (where there was some diversity and some natural values).

The annual median number of new nest holes made by all woodpecker species per square kilometre was 5.7 in natural forests, 4.3 in semi-natural forests and only 1.5 in managed forests. According to the researchers involved in the study, the fact that the value was also fairly high in the semi-natural forest indicates that nest hole production recovers relatively quickly when the intensity of forestry is reduced.

The great spotted woodpecker accounted for 72–78 percent of nest holes in the three forest types. According to the researchers this is because it is both the most common woodpecker species in Eurasian boreal forests and so efficient at creating nest holes, making nests in both coniferous and deciduous trees and in healthy, weakened and dead trees. However, this species also created significantly fewer nests per square kilometre in managed forests than in natural forests.

Several previous studies have shown that the great spotted woodpecker often makes holes in living but weakened trees, and in dead or damaged parts of otherwise healthy trees. There are probably fewer of these trees in intensively managed forests. In addition, there are probably more insects to feed on in natural forests, which could be equally as significant as the presence of suitable cavity trees.

The black woodpecker also usually chose living, but weakened or damaged, trees for its nests. The nests of the other four species, which were less common, were mainly in dead or dying trees.

The study also showed that woodpeckers created holes in deciduous trees more often than in conifers. It is already known that aspen (Populus tremula) is an important hole tree for woodpeckers in boreal forests. This was also confirmed in this study, as 45–55 percent of new holes in the three forest types were in aspens.

As constructors of nest holes, woodpeckers are thus keystone species. This is a well-established concept used in species conservation. Woodpeckers fit into several such concepts. They can be bioindicators (indicator species), umbrella species and flagship species. The concepts overlap to some extent, but used correctly they can facilitate conservation work.

Flagship species are popular or well-known species that are used to generate public opinion or raise funds for conservation work. Many people recognise and admire both woodpeckers and their drumming.

Bioindicators are species whose condition reflects the state of a particular environment. Woodpeckers can be indicators of deciduous forest environments with high biodiversity. For example, the white-backed woodpecker is an indicator species for forest environments with abundant dead hardwood.

Umbrella species are species with particularly demanding habitat requirements. Protecting umbrella species also helps to protect other species with similar requirements. The white-backed woodpecker is the specialist among specialists. Its diet consists largely of insects that live in hardwood and bark, especially beetle larvae. This is why it needs a plentiful and continuous supply of insect-infested, dead or dying deciduous trees. Because such environments are important for several threatened species, the white-backed is also an umbrella species. In a couple of the historically well-recognised nesting areas of white-backed woodpecker in Sweden, about 200 red-listed species have been found (4).

The reason I saw a white-backed woodpecker in the early 1990s was because I was writing an article about a new project to conserve the species: the White-backed Woodpecker Project, managed by the Swedish Society for Nature Conservation along with several other organisations. I had been invited to accompany project members to the most recently discovered site in the country. The year before, a nest had been found there, but now only the drumming of this single female was heard. That was a bad sign.

Today, the species is mainly found in three regions of Sweden, and the area where I saw the white-backed is not one of them.

White-backed woodpeckers are found in a belt from Scandinavia and Eastern Europe in the west, to Japan and the Kamchatka Peninsula in the east. In much of Europe, only small, scattered populations remain. Viable populations are found in eastern Poland, the Baltic States, western Norway and Belarus.

In the 1990s the white-backed was just as endangered in Finland as it was in Sweden, with perhaps 10 pairs in the whole country. But in the latest Finnish Red List, published in 2019, the species has jumped up two categories, from critically endangered to vulnerable. It is now estimated that there are more than 300 breeding pairs in the country. The recovery is due to active measures, such as protecting forests, removing spruce and ensuring that there is dead hardwood in areas where the white-backed woodpeckers live.

However, according to the Finnish Forest Agency, which manages state-owned land in Finland, even more forests need to be protected to secure enough suitable nesting sites (5).

In Sweden, the species is still red-listed as critically endangered. In 2023, some 60 white-backed woodpeckers, including 20 pairs and 11 confirmed nests, were observed in the country (6). The figures are described as both encouraging and worrying. On one hand, this is the best result in the three-decade history of the White-backed Woodpecker Project, but on the other, it is a long way from the 250 individuals which, according to the project, set the lower limit for a viable population.

In addition to protecting and restoring the species’ habitats, the project now also works on releasing young birds raised for breeding. Influencing forest policy is also a priority. This is not an easy task.

For example, Sweden, which has a large forest industry that has strong lobbying power, made concerted efforts to block the EU Nature Restoration Law and voted against it when it was finally approved by the Environment Council on 17 June 2024.

Clear-cutting of deciduous forests, thinning and other felling of deciduous trees is a constant threat to the white-backed woodpecker. Lack of regeneration of deciduous forests, especially aspen and goat willow (Salix caprea), in the areas where the white-backed woodpecker is found is also a major problem. Spruce is taking over and the numerous deer and moose graze on deciduous saplings.

If the species is to survive in the long term, larger and better connected areas with a high proportion of deciduous trees and dead wood are ultimately needed.

Karin Bergqvist

(Karin Berqvist is a science writer/journalist from Sweden)

 

References

1. SLU Artdatabanken. https://artfakta.se/taxa/Dryocopus-martius-100049/information

2 Aubry KB, et al. (2002) The Pileated Woodpecker as a Keystone Habitat Modifier in the Pacific Northwest. USDA Forest Service, PNW Research Station, Olympia, WA. https://www.fs.fed.us/psw/publications/documents/gtr-181/023_AubryRaley.pdf

3 Pakkala T, et al. The intensity of forest management affects the nest cavity production of woodpeckers and tits in mature boreal forests. Eur. J. Forest Res. 143, 617–634 (2024). https://doi.org/10.1007/s10342-023-01645-x

4. Action programme for the white-backed woodpecker 2017–2021. Swedish Environmental Protection Agency Report 6770; May 2017. https://www.naturvardsverket.se/4a6920/globalassets/media/publikationer-...

5. Metsähallitus. https://www.metsa.fi/sv/natur-och-kulturarv/skydd-av-arter/vitryggig-hac...

6. Swedish Society for Nature Conservation. https://www.naturskyddsforeningen.se/artiklar/projekt-vitryggig-hackspett/

Carbon uptake by Swedish forests falls sharply

By: 
Karin Bergqvist

Net uptake in Swedish forest land 1990–2023, source Swedish Environmental Protection Agency. Diagram, available on the Swedish EPA website: https://www.naturvardsverket.se/data-och-statistik/klimat/vaxthusgaser-nettoutslapp-och-nettoupptag-fran-markanvandning/

Sweden faces an uphill struggle to meet EU climate targets for its forests by 2030. Under EU legislation, net greenhouse gas uptake by forests and land in Sweden should increase by 4 million tonnes of carbon dioxide equivalent by 2030, compared with 2016–2018. But the trend is heading in the opposite direction. Instead, the latest figures show a decrease of 15 million tonnes.

Net greenhouse gas uptake by land use and forestry in Sweden remains high, accounting for around 70 percent of the country’s emissions from all other sectors. But the level of uptake is decreasing year on year.

In December 2024, the Swedish Environmental Protection Agency published its latest statistics on greenhouse gas emissions and removals (1). They show that net uptake by forests and land in 2023 was 31 million tonnes of carbon dioxide equivalents, the lowest value since measurements began and 7 percent less than the previous year. This figure can also be compared with the annual average for the entire measurement period 1990–2023, which is around 55 million tonnes.

The figures were produced using an improved methodology and more data than in previous years. The estimates become more reliable as the methodology becomes more refined, and the figures for the whole period can then be updated. This means that the net uptake figure for a given year, 2016 for example, is no longer the same as in last year’s report, and may change again in the future.

Under the Land Use and Forestry Regulation (LULUCF), Sweden is obliged to increase its net uptake in the sector by 4 million tonnes of carbon dioxide equivalent by 2030 compared to the average for 2016–2018. The latest figures give an average value for 2016–2018 of 46.2 million tonnes per year. If 4 million tonnes are added to this, Sweden’s commitment would be a net removal of 50.2 million tonnes. The latest figure of 31.2 million tonnes in net removals therefore means that Sweden currently has a shortfall of 19 million tonnes below the 2030 target level.

Although the figures are continuously updated, the message is clear. We are heading in the wrong direction and it will be very difficult to reach the target.

Part of the land use sector’s net uptake is due to harvested wood products. But by far the largest share of uptake takes place on forest land – by mineral soil, dead organic matter and living trees. Arable land and the other land types in the sector are net emitters.

Forests sequester carbon dioxide through photosynthesis, but also release the gas into the air through cell respiration. Following clear-cutting, forest land emits more carbon dioxide than it absorbs. As trees grow back, uptake increases. After some time, usually decades, a balance is reached and then the forest becomes a carbon sink for many years.

Net uptake by Swedish forests has been high for many decades. There are several reasons for this. Since the mid-twentieth century, forest policy has contributed to increase timber stock. Forests have been planted on abandoned agricultural land and drained wetlands.

Environmental factors such as nitrogen deposition and climate change have also contributed to increased forest growth. Moreover, a large proportion of the country’s forests had been felled by the beginning of the 20th century, so a significant part of the increasing carbon uptake since mid-century has simply been recovery.

Nevertheless, over the last decade, annual net uptake by forests has decreased drastically, from 58 million tonnes of carbon dioxide equivalent in 2013 to 32 million tonnes in 2023. This reduction is almost double the emissions from all domestic transport in 2023 (2). The largest decrease in net uptake has been due to living trees.

According to the Swedish Environmental Protection Agency, the reason for the decline is that forest growth is no longer increasing, but has levelled off, while felling is increasing. More trees have also died due to drought and insect infestation. The increase in felling is a result of higher demand and higher prices for the raw material.

A summary of the current state of knowledge from Lund University shows that two measures in particular can increase the climate benefits of Swedish forests (3). One is to enhance carbon sequestration, mainly by reducing deforestation. The other is to use harvested wood to make more durable products and to replace fossil-intensive products, which is known as substitution. Substitution effects are difficult to calculate; they appear to have been overestimated in previous studies and are not a near-term solution. Reduced deforestation, on the other hand, provides immediate and certain climate benefits, and is the measure with the greatest effect in the coming decades.

In spring 2025 the Swedish Environmental Protection Agency will evaluate how emissions and uptake of greenhouse gases will affect Sweden’s climate goals. This evaluation will form part of the basis for the Swedish Government’s climate report.

Karin Bergqvist science writer/journalist

Sources

  1. https://www.naturvardsverket.se/data-och-statistik/klimat/vaxthusgaser-nettoutslapp-och-nettoupptag-fran-markanvandning/
  2. https://www.naturvardsverket.se/data-och-statistik/klimat/vaxthusgaser-utslapp-fran-inrikes-transporter/
  3. Rummukainen M (2024). Skogens klimatnytta 2.0 – Klimatomställning nästa. CEC Synthesis no. 8. Center for Environmental and Climate Research, Lund University.

The climate benefit of Swedish forests can be improved

By: 
Karin Bergqvist

The most effective way to improve the climate benefit of Swedish forests is by harvesting less. This is a brief summary of the current state of knowledge.

Markku Rummukainen, Professor of Climatology at Lund University, has compiled scientific literature and reports from authorities on the climate benefit of forests, primarily in Sweden (1).

There are two main ways to increase the climate benefit of forests. One is to increase their carbon uptake, mainly by reducing deforestation. The other is to use the wood from trees to make longer-lasting products and replace carbon-intensive products.

It is urgent that we limit global heating, and Sweden has binding EU targets to increase the carbon uptake of forests by 2030. Transitioning to new products will take much longer than that. Improving carbon sequestration, on the other hand, provides immediate climate benefit, and is the measure that will have the greatest impact in the next few decades.

These are the main conclusions of Markku Rummukainen’s synthesis, published in June 2024.
Forests act as carbon sinks. A carbon sink absorbs carbon dioxide from the atmosphere and stores the carbon for a period of time. From a global perspective the main carbon sinks are vegetation on land, especially forests, and the oceans.

Carbon dioxide is absorbed by the oceans when it dissolves in water or is used by phytoplankton during photosynthesis. Plants on land also use carbon dioxide for photosynthesis.
But trees and other plants, like most living organisms, also release carbon dioxide into the air during the chemical process of respiration. And carbon dioxide is released from the soil in forests through respiration, by the roots of trees and when dead plants decompose.

When a forest is clear-cut, it reduces photosynthesis more than it reduces respiration, so more carbon is released than absorbed. As the forest starts to grow back, carbon uptake and sequestration increase. After a while, a balance is reached and the forest becomes a net carbon sink for a long period of time.

In the mid-twentieth century, carbon sequestration started to increase as the forests of northern Europe grew. Forest policy, which mainly focused on increasing the supply of timber, contributed to this increase. The draining of wetlands to grow more trees is also a factor. But environmental factors such as nitrogen deposition and climate change have also had an impact on growth. In addition, large areas of forest had already been felled by the beginning of the twentieth century, so some of the increase in carbon uptake was simply part of recovery.

Over the last decade, the annual carbon sequestration of forests in the EU has actually decreased, partly due to increased harvesting. Between 2000 and 2021, EU deforestation increased by around 25 per cent. Net sequestration has also been impacted by reduced reforestation and growth, while forests have been hit by storms, fires and bark beetle infestations.
Markku Rummukainen’s research synthesis shows that the most obvious course of action to reverse this trend is to reduce deforestation.

In Sweden, 97 per cent of productive forest land is managed by clear-cutting.

It is widely accepted that clear-cutting results in net carbon emissions for a number of years after felling. Estimates of how many years emissions remain higher than uptake vary somewhat. The figure also varies from stand to stand. However, current studies show that it is a matter of decades rather than a few years.

One of the studies cited in the synthesis covers five stands in southern Sweden that were clear-cut or wind-felled (2). They produced net carbon emissions for about 10 years after felling, and it took around 20 years for total carbon uptake to balance net emissions.

Another study from northern Sweden covered around 50 stands. In this case it took an average of 18 years for net emissions to be balanced by carbon uptake. However, this time period may be greatly underestimated because the calculations omitted data for the first year after felling (3, 4), when net emissions are highest.

Carbon uptake can also be improved by thinning trees less intensively, protecting areas of forest and allowing trees to grow older before felling.

Until recently there was an incomplete understanding of the balance between carbon dioxide uptake and emissions in really old forests. But the synthesis notes that several studies have now shown that forests remain carbon sinks long after they have passed the age when they are usually felled.

One study showed that the uptake of over 1000 Norwegian coniferous forest stands continued to rise for 50–100 years after the usual felling age (5). Another showed that forests aged between 130 and 200 years old in the north-east US and south-east

Canada remained a significant carbon sink (6). In Sweden, the average final felling age for the country as a whole is just under 100 years.

The second way to increase the climate benefit of forests, alongside reducing deforestation, is to use the harvested wood in a more carbon-efficient way.

Only a fifth of the wood harvested in Sweden is used to make durable wood products. The rest is used to generate bioenergy and make pulp, paper and cardboard which, even when paper is recycled, is burned after a relatively short time, returning carbon to the atmosphere.

Substitution means that wood that is used to make long-lived or short-lived products that replace fossil-intensive materials or fossil energy. For example, cement can be replaced with timber building materials. Coal, oil and fossil gas can be replaced by biofuels.

The climate benefits of substitution are estimated by calculating a “substitution factor” (or displacement factor). This factor is based on a number of assumptions, such as which products are being substituted, how they would be produced and their life-cycle emissions. The climate benefits of substitution should also take into account the value of leaving the carbon sink in the forest instead of extracting the wood at all, as well as alternative uses for the wood.

Different studies are based on different assumptions and it is not always clear which assumptions were made. This makes it difficult to compare studies. However, the research synthesis notes that the substitution factor is generally always positive, which means that when fossil-intensive materials and fossil energy are replaced with wood, some emissions are avoided. But it should also be noted that the substitution factor tends to be lower in more recent studies than in older studies.
It is also uncertain how the estimated climate benefit of a given substitution will hold up in a changing future. It could drop considerably if new production methods and materials are developed, recycling increases, energy systems change or material use decreases.

Overall, the research shows that at current levels of wood usage, greater climate benefit can be achieved by increasing carbon uptake in forests than by increasing felling. The latter would require a large and rapid change in the way that wood is used, which is unrealistic within the next few decades. On the other hand, reducing deforestation would provide an immediate increase in climate benefit. Nevertheless, switching to new products can make a significant contribution to increasing the climate benefit of forests and is therefore an important measure.

The synthesis does not directly address the issue of forest resilience, i.e. resistance to climate-related damage. However, some studies are mentioned that touch on this subject. There are many indications that forest damage has increased in Europe in recent years, and that this is at least partly due to climate change. For example, damage has been caused by bark beetle infestations, storms, forest fires and extreme drought. These lead to increased emissions and reduced carbon sequestration. To maximise climate benefit it is therefore important to use forestry methods that increase resistance to damage. Influential factors include felling method, tree density, species selection, planting material and early detection of pests.

Finally, Markku Rummukainen concludes that it is entirely possible to increase the climate benefits of forests in ways that benefit both the forest owner and society, and hence get closer to climate goals. However, this will require changes in forestry and the forest industry. This in turn requires political decisions, economic and legal instruments and awareness-raising.
“It is reasonable that forest owners should be given the opportunities to improve the climate benefits of forests, for example by receiving compensation for measures that increase carbon uptake. This would also benefit Sweden as a whole by increasing the potential for us to meet our climate commitments, while providing other important benefits in terms of value from the forest,” commented Markku Rummukainen in a press release from Lund University in connection with the publication of the synthesis.

Karin Bergqvist
science writer/journalist

Sources

  1. Rummukainen M (2024). Forest climate benefits 2.0 – Climate transition next. CEC Synthesis No 8. Centre for Environmental and Climate Science, Lund University.
  2. Grelle, A. et al. 2023. Agricultural and Forest Meteorology. doi:10.1016/j.agrformet. 2022.109290
  3. Peichl, M. et al. 2023b. Global Change Biology. doi:10.1111/gcb.16772
  4. Lindroth, A. 2023. Global Change Biology. doi:10.1111/gcb.16771
  5. Stokland, J.N. 2021. Forest Ecology and Management. doi:10.1016/j.foreco.2021.119017
  6. Thom, D. et al. 2019. Global Change Biology. doi:10.1111/gcb.14656

Forests in Sweden

By: 
Karin Bergqvist

Introduction: Almost 70 percent of the land area of Sweden is forest land. Karin Bergqvist describes how important forests are for people, communities and biodiversity, and how they are used and managed in Sweden.

Autumn 2023: It’s Saturday morning and I’m walking through the forest towards a pine bog with about twenty other people, all with magnifying glasses hanging from lanyards around their necks. We are members of a botanical society and today we are going to learn how to identify different species of sphagnum moss.

Around Sweden, several hundred thousand people are probably out in the forest at the same time as us. In a survey conducted by Statistics Sweden in 2022, 40 percent of Swedes (16 years and older) said they had spent some of their free time out in the forest and countryside every week during the past year [1].

Visiting the forest is easy for us, as we live in a heavily forested country. Almost 70 percent of the land area is forest land, at least according to the generous definition of the Food and Agriculture Organization (FAO), which includes clearings.

Sweden’s “Right of public access” also gives residents the right to walk on private land in the countryside and pick berries, mushrooms and many other plants.

Recreation is an ecosystem service that is largely associated with the forest and is probably undervalued economically. Stepping through soft moss, filling jars with berries and baskets with mushrooms, listening to the hammering of a woodpecker and smelling the perfume of wild rosemary and bog myrtle naturally make us feel good, but also have measurable benefits for our health.

A meta-analysis of 21 studies [2] has shown that, compared to a control group, “forest therapy” lowers our blood pressure and the concentration of cortisol in saliva (biomarkers of stress).

Several studies have also shown that people perceive old-growth forests as having a greater recreational value than younger forests that are harvested regularly [3]. 

Unfortunately, old-growth forest is not as easy to find in Sweden as intensively managed forest.

Sweden is one of the world’s largest producers of pulp, paper and sawn timber. According to statistics for 2020, Sweden is the fourth largest exporter of pulp, paper, cardboard and sawn timber in the world (after Canada, Russia and the United States). According to the forest industry’s trade association, 69.5 million cubic metres of the raw material supply was domestic and 6.3 million was imported in 2022. In the same year almost 96 million cubic metres of forest were harvested in Sweden.

Clear-cutting has completely dominated Swedish forestry since the 1950s, as it does today, while many other EU countries have more or less abandoned it. In 2022, only about 3 percent of Sweden’s productive forest land was used for continuous cover (clear-cut-free) forestry [4].

Productive forest land is defined as land that on average can produce at least one cubic metre of wood per hectare per year. Out of 27.9 million hectares of forest land in Sweden, 23.5 is classed as productive forest land. Almost half of this productive land is owned by individuals/family enterprises, while private limited companies own a quarter. Public limited companies and the state together own 20 percent, much of which is located in the northernmost part of the country.

Back to autumn 2023 and our moss hunt. We tread between pine trees of various ages and sizes. The terrain is slightly hilly, but quite easy to navigate. Here and there, a blanket of star-tipped cup lichen lights up a rock face. Goldcrests chirp and we even hear a crossbill. It feels like we are in a vast wilderness in the far north of Sweden. But we are just 25 kilometres west of Stockholm. The mix of trees also breaks the illusion of northern latitudes. There are not only aspen but also oak dotted here and there among the pines, and on a steep slope some sturdy small-leaved lime trees (Tilia cordata) with yellow autumn leaves reach towards us as we tread the path beneath them. We are in the boreonemoral forest.

Swedish statistics on forest protection divide the forest into five natural geographic regions that reflect county boundaries [5] (see map): mountainous forest (9 percent of forest land), northern boreal forest (25 percent), southern boreal forest (36 percent), boreonemoral forest (26 percent) and nemoral forest (4 percent).

According to the EU’s biogeographical classification, Sweden’s land surface is divided into three regions: alpine, boreal and continental (see map). The majority of forests are located in the boreal region. Spruce (Picea abies) and pine (Pinus sylvestris) are by far the most common tree species in Sweden. Barely 19 percent of the timber stock consists of deciduous trees – up from 15 percent in 1990. Since then, some requirements to promote deciduous trees have been introduced into environmental objectives and forest certification criteria. The most common deciduous trees, measured as timber stock, are birch (Betula pendula and Betula pubescens), aspen, and alder (Alnus glutinosa and Alnus incana), which grow throughout the country, and in southern Sweden oak and beech.

During our moss hunt we repeatedly have to wait for a few stragglers. Our guide, who tries to maintain the pace, grunts “Where are they now?”.

“They’re huddled around a log,” someone says.

There are plenty of moss-covered fallen dead trees here, and for those with a keen interest in mosses these are not easy to ignore. Dead wood is vital for many of the species of moss in the forest, and for many lichen, fungi and insects.

A pine tree, perhaps 15 metres tall, stands in front of us with an elongated, vertical slash in its bark, exposing the wood. This is a scar from the heat of a forest fire. It is a sign of the high nature value of this forest, as burnt forests are becoming increasingly rare and are home to many species that can only be found there.

The signs of fire, dead wood, and trees of different heights all point to the fact that we are surrounded by a highly biodiverse forest that should be protected. But we can rest assured that this forest is already protected. It is part of a nature reserve.

Across Sweden, 7 percent of the forest land (5.9 percent of the productive forest land) is strictly protected, according to the definition of the EU Biodiversity Strategy [6, 7]. But this protection is unevenly distributed. Only 3 percent of the boreonemoral forest, where our moss hunt takes place, is strictly protected. The average figure for the country as a whole is higher because just over half of montane forest land is strictly protected, while only 4 percent of nemoral forest, 3 percent of northern boreal forest and 2 percent of southern boreal forest are strictly protected. 

8.9 percent of the total forest land in Sweden is formally protected, according to Statistics Sweden. Formal protection includes strictly protected forests as well as areas where there are special protection agreements. 61 percent of the formally protected forest land is in the mountainous region. 

In autumn 2023, the Swedish Environmental Protection Agency and the Swedish Forest Agency assessed how much primary forest and old-growth forest in Sweden lacks strict protection [7].

The starting point is the guidance issued by the European Commission in March 2023 [8] to enable member states to effectively identify and protect primary forests and old-growth forests. The EU Biodiversity Strategy for 2030 calls for 30 percent of EU land area to be protected, of which one-third should be strictly protected. All remaining ancient and natural forests in the EU should be strictly protected. 

Because the definitions of primary forest and old-growth forest are similar, both the EU and the Swedish authorities have taken the practical decision to include primary forest in the classification of old-growth forest.

The Swedish authorities have compiled existing older data from field inventories and surveys of continuous growth forests. Based on these, they assess that the area of old-growth forest in the areas covered by the data and which lack strict protection corresponds to around 8–10 percent of all forest land and around 6–8 percent of productive forest land. There may also be other natural forests without strict protection outside these areas, although not to the same extent.

As much as 35–40 percent of old-growth forest in the areas covered by the existing data is estimated to be in mountainous forests, about 30 percent in northern boreal, 20–25 percent in southern boreal, just under 10 percent in boreonemoral and a one or two percent in nemoral regions.

Our moss hunt is over and we have been able to identify more than 20 species of sphagnum moss as well as a few other moss species along the way. The diversity of species often brings to mind tropical rainforests. But when it comes to mosses (leaf mosses, liverworts and hornworts) there are almost as many species in Sweden as in Costa Rica. Can we sustain this diversity?

The forest is one of the most important environments for mosses in Sweden and they are severely impacted by clear-cutting, as are many other organisms. According to a summary published in 2022, several hundred of Sweden’s threatened species are in fact threatened because of clear-cutting [9]. At the same time, 97 percent of managed forests are harvested by clear-cutting.

Hopes are currently pinned on the EU. We cannot count on Sweden’s politicians. Between March and June 2023, the EU Council of Ministers adopted three legislative proposals for forests: the new LULUCF Regulation on carbon sequestration in forest soils; the Deforestation Regulation to prevent trade in goods such as coffee and soya, which can lead to deforestation or forest degradation; and the Regulation on the restoration of degraded land. On each occasion, Sweden voted against or abstained from the proposal.

The Swedish government justified its decision not to support the LULUCF Regulation on the grounds that “the proposal as it has been finalised entails significant restrictions on Swedish forestry”.

Karin Bergqvist
(Karin Berqvist is a science writer/journalist from Sweden)

Caption to map: Sweden, divided into the three biogeographical regions that cover the country’s land surface and the five natural geographic regions used in Swedish statistics on forest protection. Map taken from ref 7, page 39.

References

  1. SCB (2023). https://www.scb.se/hitta-statistik/statistik-efter-amne/levnadsforhallanden/levnadsforhallanden/undersokningarna-av-levnadsforhallanden-ulf-silc/pong/tabell-och-diagram/fritid/andel-som-under-de-senaste-12-manaderna-varit-ute-i-skog-och-mark-pa-fritiden-minst-en-gang-i-veckan-ulf-20082022/
  2. Qiu Q, et al. The Effects of Forest Therapy on the Blood Pressure and Salivary Cortisol Levels of Urban Residents: A Meta-Analysis. Int J Environ Res Public Health. 2022 Dec 27;20(1):458.
  3. Edwards DM, et al. “Public Preferences Across Europe for Different Forest Stand Types as Sites for Recreation.” Ecology and Society 17, no. 1 (2012). http://www.jstor.org/stable/26269008).
  4. Forestry Commission (2023). https://www.skogsstyrelsen.se/statistik/statistik-efter-amne/atgarder-i-skogsbruket/
  5. Swedish Forest Agency, Swedish Environmental Protection Agency: Forestry Organisation’s evaluation of the effects of forest policy – SUS 2001.
  6. European Commission. Criteria and guidance for protected areas designations. SWD(2022) 23 final. 
  7. The Swedish Forest Agency, Swedish Environmental Protection Agency. Primeval forests and natural forests – compilation of data and assessment of areas. Knowledge base for the Environmental Objectives Committee. SKS: 2023/3258. NV-02484-23.
  8. European Commission (2023). Commission Guidelines for Defining, Mapping, Monitoring and Strictly Protecting EU Primary and Old-Growth Forests. 
  9. SLU Artdatabanken, WWF. Forest species threatened by modern forestry. https://www.wwf.se/dokument/skogliga-arter-som-hotas-av-modernt-skogsbruk/
 
Published by AirClim (Reinhold Pape)
The views expressed here are those of the authors and not necessarily those of the publisher.
 
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