The night of January 8-9, 2005, is engrained in the memory of Swedish forest owners, the forest industry, energy utilities, and civil- and municipal agencies as storm Gudrun swept right across the southern third of Sweden in a west-to-east direction. Having felled more forest in Sweden than any other known storm, what has been learnt from a storm like Gudrun.
Overnight, the landscape in southern Sweden, primarily Götaland but also parts of southern Svealand, became unrecognizable, morphing into a surrealistic apocalyptic scene from a doomsday movie—an estimated 200 to 250 million trees had been blown over or had snapped stems.
Once the storm – which recorded hurricane gusts of 42 metres per second – subsided, nine people had lost their lives, thousands of forest owners lost their forests, 730,000 households, businesses, and industries were without electricity, many without telecommunications, and out of reach as fallen trees, and power lines blocked roads and rail lines.
Bear in mind that this is January in southern Sweden when temperatures are normally below freezing.
Unprecedented scale
While natural forest disturbance in the form of storms, insect infestation, and wildfires is not uncommon, and best management practices are in place to mitigate and handle such events, storm Gudrun felled nonetheless more forest in Sweden than any other known storm.
According to the Swedish Forest Agency, the winds which averaged speeds of 33 metres per second, felled and snapped approximately 10 percent of all forests in Götaland.
In roundwood terms, some 75 million m3 of timber – a volume equivalent to almost one year’s harvest in the entire country or three years’ harvest in Götaland – downed in a day.
A total of 270,000 hectares (ha) of forest were damaged by storm Gudrun. Between 110,000 and 130,000 ha were so devastated that reforestation obligations arose highlighting the severity of the storm for forestry and forest owners.
In other words, the forests on these holdings were wiped out or damaged beyond repair essentially equivalent to a clearcut in forest regulation terms, so starting over with reforestation was the legal outcome.
Many forest owners saw the efforts of their lifelong mission of handing over a forest estate to the next generation in better ecological and economic shape than when they acquired or inherited it, destroyed – tragically reflected in the final death toll attributed to storm Gudrun that had doubled to 18 people.
Roughly the same area was hit by a storm in December 1902. At that time, local newspapers reported from Ljungby in Småland describing the scene: “After the storm on December 25-26, the forests looked like a rye field where the scythe has passed”, a vivid description that aptly fits some of the images 103 years later.
In living memory, the most commonly referred to year when it comes to benchmarking storm damage in Swedish forests is 1969. It is also the one that many older forest owners still remember and talk about.
Figures from the Forest History Society on wind-felled forests in previous storms suggest that storm Gudrun downed over twice as much forest as the two 1969 storms did, combined:
- 1931 December storm – c. 2 million m3
- 1932 February storm – c. 2 million m3
- 1943 February & March storms (two) – c. 6 million m3 in total
- 1954 January storms (four) – c. 18 million m3 in total
- 1967 October storm – c. 10 million m3
- 1969 September & November storms (two) – c. 36 million m3 in total
- 1999 November-December storms (four) – c. 5 million m3 in total
Södra members took a heavy hit
Southern Sweden is home to Södra Skogsägare, Sweden’s largest forest owners association with around 53,000 members. Founded in 1938, Södra also owns and operates pulp mills and sawmills throughout the region.
Just over half of the total volume felled by storm Gudrun – c. 40 million m3 – was on a forest property belonging to a Södra member, while numerous other forest owners in the region including large owners such as the Church, municipalities, and National Property Board also suffered significant damage.
For Sweden’s largest forest owner, state-owned Sveaskog, storm Gudrun downed, by comparison, a modest 2.6 million m3fub on Sveaskog-owned estates in southern Sweden, which is equivalent to one and a half year’s worth of annual fellings on the said estates.
Mobilizing cleanup and timber salvage operations
Once the storm passed, clean-up priority for the first weeks was given to making roads passable and restoring the electricity supply, and telecommunications.
Some 800 military service personnel were called in to assist utilities and forest contractors with emergency clearing, transportation, and setting up new communication networks.
Ove Ohlsson, Sveaskog’s felling manager for region Götaland at the time, remembers a job that began in panic.
There was panic at the beginning and we really had to think about where to start with the resources we had. We prioritized opening roads to houses on our land and helping power companies access lines and centers. We drove harvesters along the roads and beside power lines. In many places, the wind-throws were several meters high, Ove Ohlsson recalled.
After the initial shock had subsided, and immediate emergency clearing for roads, tele- and power utilities completed, everyone working with the storm-felled forest understood that a herculean task for all parties concerned lay ahead – to salvage and extract as much timber felled by the storm as possible.
They also realized that the existing resources would not be enough.
The hunt for labor and contractors was intense with people from all over the country and Europe coming to help with salvage logging and extraction operations.
Södra commissioned machinery and personnel from throughout its organization to the hardest hit areas first, and by the spring, had over doubled the number of logging crews. At its peak, Södra had crews from 15 countries operating on its member forest holdings.
Sveaskog on the other hand was able to mobilize resources from the central and northern parts of the country where it has the lion’s share of its 3.9 million hectares (ha) forest estate.
Sveaskog was able to move resources from Bergslagen (central Sweden) to the area, and then part of the planning shifted to arranging housing and logistics for everyone who came in from outside. There were many machine groups, but also work management that came down with them. Our strength was that we could utilize Sveaskog’s potential in moving resources and machines, Ove Ohlsson said.
At its peak, Sveaskog had 152 machine teams and 120 timber trucks per day working on the affected estates compared with a normal working day when 50 machine teams and 20 trucks work in the same area.
Södra’s SEK 50 price guarantee
Industrial roundwood, such as sawlogs, and pulpwood is a fresh commodity and degrades in quality over time. Quality degradation such as sapwood blue stain or insect damage can take hold if the logs begin to dry out.
In other words, a forest owner loses money the longer potential sawlogs- and pulpwood remain in the forest as windthrows, uncollected logs at roadside, or a storage terminal if it is not equipped for long-term log storage.
To optimize safe- and rational salvage logging and extraction operations, while avoiding arguments over which forest owner gets salvaged first, Södra’s board decided on a pricing model whereby members were promised a price guarantee in which everyone received the same compensation regardless of when the timber was processed.
It was not easy to find a guaranteed price that was at a reasonable level, but it was a very good decision that reassured the members and gave the staff peace of mind, said Magnus Petersson, Head of Forest Development at Södra.
Government support
Intensive economic policy work by forest owners’ associations, along with other forestry industry stakeholders, to ensure that affected forest owners would receive financial compensation for lost timber income led to the Swedish government’s decision on an extra SEK 50 per m3 as a tax reduction.
The government also established a “storm-support” disaster fund and the Swedish Forest Agency received a total of SEK 1.065 billion during 2005-2008 to deal with the after-effects of storm Gudrun.
Funding from the storm support disaster fund was used for regeneration support, grants for the construction and operation of roundwood storage terminals, monitoring and analysis, advisory and information efforts regarding insect infestation, grants for repairs and maintenance of forest roads, preventive measures to mitigate extraction damage, and restoring forest land with high conversation values that had been affected by post-storm extraction damage.
Some SEK 450 million from the fund was earmarked for regeneration support to affected landowners – SEK 328 million was paid out in total.
Mobilize long-term storage
Hypothetically, even if salvage logging and extraction had been able to make ready 75 million m3 of timber overnight, the Swedish forest industry wouldn’t be able to process a year’s worth of industrial roundwood in a short timeframe necessitating the need for terminals for long-term storage of logs.
Wet storage by the constant sprinkling of water on log stacks is the conventional process used at sawmills to store- and preserve sawlog quality and is considered by researchers and forest practitioners to be the most reliable for long-term storage, typically two to six years depending on the species.
After storm Gudrun, Södra had over ten million m3 of storm-felled timber in long-term storage simultaneously at terminals, sawmills, pulp mills, and roadside.
In November 2009, almost five years after storm Gudrun, the last load of storm-felled timber was collected from a terminal in Asige in Halland to be processed in Södra’s industry.
According to Södra, only a very small percentage of the storm-felled timber was unusable on account of long-term storage.
Our success after storm Gudrun was a result of the strength, commitment, and expertise of Södra as a cooperative, which today has more than 50,000 family foresters and just over 3,000 employees, and in close collaboration with our forestry contractors, summarised Henrik Andersson, member manager at Södra.
For VIDA Group, Sweden’s largest independent forest industry group (now part of Canfor) the storage solution was on a spectacular scale. Having no forest of its own, VIDA is dependent on procuring logs from forest owners, and third-party suppliers to its sawmills.
In the weeks following the storm, VIDA secured permission to utilize Byholma, a former military airstrip outside Ljungby, and converted the airstrip into a gigantic temporary wet-storage terminal for storm-felled timber.
From a central passage running the length of the airstrip, a tracked harbor crane with a 20-metre reach stacked the logs in twelve rows – six on each side of the passage. Each row was 2.3 km long, and 13 metres in height.
According to Kurt Lenngren who came in from retirement to act as Site Manager for VIDA’s Byholma terminal, the site had up to 1,000 visitors a day from Sweden and abroad during the first year of operations.
VIDA began processing the stored timber at its Vislanda, and Alvesta sawmills in January 2008, and on April 29, 2010, the last truckload of storm-felled timber left Byholma.
Better equipped agency
Despite the unprecedented forest damage, storm Gudrun in itself was not an extreme storm. There have been several severe storms to hit Sweden and Swedish forests since, some recording higher wind speeds over land than Gudrun did.
Already in January 2007 storm Per hit southern Sweden again moving northwards to take around 12 million m3.
In December 2011, storm Dagmar hit central-northern Sweden felling approximately 4.5 million m3.
In the autumn of 2013, a storm quartet – Simone, Hilde, Sven, and Ivar – felled a combined total of 14 million m3, while two storms during 2015 – Egon (January) and Gorm (November) – downed 3 million m3 and 2 million m3 respectively again in southern Sweden.
Twenty years on since Gudrun, the forest sector, and the Swedish Forest Agency are better prepared for storms and other forest damage.
We have built an organization with damage coordinators throughout the country and a forest damage group that will be able to handle sudden forest damage events quickly and effectively. We have increased knowledge about forest damage both internally and externally with advice and information, said Lennart Svensson, National Forest Damage Coordinator at the Swedish Forest Agency.
The Swedish Forest Agency’s role in the event of major damage outbreaks is to coordinate, inform, and support. This entails bringing together forestry stakeholders to get a comprehensive picture of the situation and to inform them on how the damage should be handled and what rules apply.
In recent years, we have also strengthened our team with experts in fungi and insects. We now also have more advanced tools for forest damage work, where we can, for example, see spruce trees killed by spruce bark beetles in satellite images and orthophotos. We are more prepared for damage events today than we were then, remarked Lennart Svensson alluding to spruce bark beetle epidemics in recent years.
Lessons learned on future forestry
Södra completed the salvage logging and extraction of storm-felled timber in June 2006 and progressed to plant a new forest.
The ambition was high, which required a great deal of effort, not least from the forestry companies.
To a large extent, foreign personnel, already on site to work on clearing wind-fallen trees, took on the reforestation work.
The reforestation after Gudrun fundamentally changed the way we work with forest management. Previously, most of this work was carried out by the forest owners themselves, but in conjunction with the storm we began to build up a corps of forest management contractors that we now use for land preparation, planting, and clearing, said Magnus Petersson.
The species mix and advice for forest management have also changed and have become more focused on climate adaptation.
We probably learned too little about how to create a storm-resistant forest, just like we did in 1969. I often think about how we probably shouldn’t keep the spruce forest for too long and that it’s a pity to cut down the pine too early, commented a reflective Ove Ohlsson.
According to the Swedish Forest Agency, 80 percent of all the trees that fell or snapped stems during storm Gudrun were Norway spruce (Picea abies), a commercial native softwood species but more susceptible to storm damage than Scots pine (Pinus sylvestris), the other commercial native softwood species or hardwood species.
Already then we advised on more diverse planting and planting the right plants on the right land to avoid future damage. But immediately after Gudrun, few were receptive to that advice. An estimated 87 percent of the storm-affected forest was replanted with spruce based on data from the paid-out regeneration support. Today, there is much more pine in the regeneration stands and now it is obvious for many to adapt their forests to the climate, commented Lennart Svensson.
Södra’s advice today is based on active forest management and the new forest is managed with more storm-adapted methods.
Gudrun, and the storms in the years that followed, gave us important knowledge to continue developing responsible forestry. We have taken advantage of the lessons learned through new management instructions to reduce future damage to the forest. Our advice has become even clearer when it comes to site adaptation, i.e. planting the right trees on the right land, clearing at the right time, starting thinnings early and avoiding thinning in older forests, and final felling of spruce-dominated stands earlier, said Magnus Petersson.
Nonetheless, Magnus Petersson notes that there are still challenges linked to the storm Gudrun. One of them is neglected pre-commercial thinning.
We can conclude that we have not reached the end when it comes to pre-commercial thinnings. We have many poorly pre-commercially thinned forests that will soon enter the commercial thinning phase, and this will affect both the execution and the result of the measure. To succeed with forest management and create opportunities for a more flexible rotation period, where the forest owner can decide when the forest is to be felled, you need to be active and invest in management measures. We must not forget that if we want to have responsible forestry, Magnus Petersson said.
Rebuilding an extreme weather-resilient grid
Apart from clearing roads, and access to powerlines, restoring electricity after storm Gundrun was further compounded by the fact that not only were overhead powerlines down or broken but over 10,000 power poles were broken and needed replacing.
Mobile gensets were brought in from military stores, power companies, and from abroad. The lack of electricity meant that many schools and healthcare facilities were closed and for some people power supply was first restored 35 days after the storm.
For energy utility major E.ON, (at the time Sydkraft), the largest utility and power grid owner in the region affected, storm Gudrun was one of the worst in the company’s history.
Over 260,000 E.ON clients were without power while for compatriot transmission grid operator Vattenfall Eldistribution, over 180,000 clients woke up without electricity on the morning of January 9, 2025.
The realization that over 20,000 km of its electricity grid was so badly damaged, E.ON decided to muster resources, and build a completely new power grid.
Storm Gudrun was a turning point for us, and it became clear how important an electricity grid that can withstand natural forces is and what significance the electricity grid has for our society, commented Jessica Krook, Head of Local Networks at E.ON Energidistribution.
An operational office in Växjö and an administrative office in Älmhult were established. Gradually, local information offices were set up to meet affected customers with assistance coming from the entire E.ON Group.
Some 2,700 employees were mobilized to work on reconstruction and customer and community contacts. Installers were flown in from other subsidiaries within the Group, mainly from Germany, the UK, and Finland.
New electrical equipment, backup generators, and electricity poles were brought in from around the world, including China, India, and Mexico. Hercules planes were used to handle the logistics, landing every night at Växjö airport.
Since storm Gudrun, E.ON has invested SEK 38 billion into weatherproofing some 33,000 km of power lines throughout Sweden, with 75 percent buried in the ground.
In southern Sweden, 1,700 km of uninsulated overhead lines were first buried and then replaced with insulated overhead lines while the right-of-way for overhead power lines in forests has been widened.
A strong electricity grid is just as important today, and that is also why we are investing in and building an electricity grid that is now 97 percent weatherproof. Then the electricity grid also needs to be able to handle an increased demand for electricity. Many customers want to be able to both produce their own renewable electricity and use more electricity. That is why we continue to invest to both strengthen and expand capacity, Jessica Krook said.
Vattenfall Eldistribution had mustered around 1,600 people of which 1,150 were in the field with a fleet of 15 helicopters, 20 tracked carriers, and 20 harvesters to help locate and rectify faults across its grid network.
We had experienced several major disruptions before Gudrun and had then realized the need for a well-tuned major disruption organization, which helped us to quickly start the fault-relief work, said Stig Skoog, a long-time employee of Vattenfall Eldistribution in Trollhättan, who at the time was Manager of the Operations Center.
Vattenfall Eldistribution too has invested heavily in the electricity grid to better withstand the effects of weather and wind. A year before storm Gudrun, Vattenfall Eldistribution had decided to invest SEK 10 billion over a five-year-period in insulating and weatherproofing its electricity grid.
Disruptions of this magnitude require solid personnel planning and scheduling. We called in all available personnel to work in the operations center. In critical situations, such as during Gudrun, it is also very important to provide transparent and clear information to customers and other stakeholders, which was a challenge. Reinforced communication resources were activated and also some support functions such as food deliveries and other services for staff who cannot leave their workplaces, recounted Stig Skoog.
During the first ten years after the storm Gudrun, Vattenfall Eldistribution invested an additional SEK 17 billion in weatherproofing measures such as widening and clearing power lines, insulating overhead lines so that they can withstand snow and ice better, and burying lines where it is deemed appropriate.
In addition to investments in weatherproofing, Vattenfall Eldistribution is currently making historically large investments in the electricity grid to meet future capacity and transmission needs.
The investment rate is approximately SEK 8–10 billion per annum until 2030.
And as 2024 goes on record as the warmest year ever – the first to exceed 1.5°C above pre-industrial levels – one can only anticipate that storms like Gudrun or worse will become more frequent.
Thus one hopes that lessons learned from catastrophic events such as Gudrun lead to better climate-adapted forests and forest management, better cross-sectoral emergency response coordination- and collaboration, and a more extreme weather-resilient power grid.
