Guidelines for Sustainable Forest Management - Holmen

2011

Guidelines for Sustainable Forest Management

Certification at Holmen Photo: David Normark

Environmental Management System ISO 14001 is an international standard developed by the International Organization for Standardization (ISO). Regular environmental auditing and gradually raised minimum standards ensure that environmental improvement is continuous.

Holme n is one of 32 9 3 0 0 forest owne rs in Swe de n .

Holmen’s history as a forest owner and manager started in 1609. Today, Holmen manages about one million hectares of productive forest land.

Ove r the ye ars , forestry has unde rgone many changes ,

as has its public image. At present, forestry enjoys a strong position in Swedish society. Swedish forestry delivers goods sustainably produced. In addition, forestry, as carried out in Sweden, contributes to carbon sequestration. Forest manage me nt to us is a fine art ,

a most stimulating endeavour, always open to public scrutiny. As we increase timber production, we remain well on track in our quest to preserve species and biodiversity. We are confident that present practices will, given time, beautify the Swedish forest landscape. Single trees and preserved areas set aside in the managed forest landscape will make our forests age with dignity. Beauty comes with age with forests.

while not jeopardising other values – quite the contrary. Our forest is a place where forestry, reindeer husbandry, hunting, mushroom picking and other outdoor activities get along. In addition, our forest has to provide adequate habitats for diverse flora and fauna. This booklet contains guidelines for the management of forests owned by Holmen. Readers will note that our guidelines make major allowances to cater for a range of different interests. We realise that our guidelines are not universally applicable. Forests and forest owners differ. It is hoped that the booklet will serve as a source of inspiration for other owners in their quest for sustainable and active forest management. We hope that readers in general will find the booklet interesting and understandable. Our tas k is to make comme rcial us e of our forest resources

Follow up and inspection. The multinational certification institutes DNV (Det Norske Veritas) and SSC (Swedish Forest Certification), both accredited by the FSC ® and SWEDAC (PEFC and ISO), ensure that certification standards are upheld.

Forestry Certification Schemes PEFC – Programme for the Endorsement of Forest Certification scheme – is an international standard for certification of forestry and forest products. The PEFC aims at promoting sustainable forestry practices that balance fibre production, environmental control and social interests. PEFC/05-31-52

Främjande av uthålligt skogsbruk www.pefc.se

FSC® – Forest Stewardship Council – is an international standard for certification of forestry and forest products. The FSC ® aims to promote environmentally appropriate, socially beneficial, and economically viable management of forests.

ISO 14001. Holmen conducts its en vironmental activities in accordance with the ISO 14001 environmental management system. PEFC – Forest Management . Holmen forests are managed according to standards set by the PEFC in Sweden. PEFC – Group Certification. Holmen can certify external wood suppliers to the PEFC standard. PEFC – Chain of Custody. Holmen has routines for tracing all timber purchased in Sweden. FSC® – Forest Management. Holmen forests are managed according to standards set by the FSC ® in Sweden. FSC® – Group Certification. Holmen can certify external wood suppliers to the FSC ® standard. FSC® – Traceability. Holmen has routines for tracing the origin of all timber purchased in Sweden.

Environmental Policy Erik Normark Domsjö May 2011

Long-term survival of domestic flora and fauna is to be secured in Holmen’s forests.

Caroline Rothpfeffer

Adverse effects on local hydrology should be keep to a minimum. Preservation of local heritage and historical sites is to be given the highest priority. Emissions/effluents in connection with logging and timber transport are to be limited.

Holmen Skog – Guidelines for Sustainable Forest Management Main author: Erik Normark, [email protected] Co-authors: Magnus Aretorn, Jonas Eriksson, Yvonne Hedman, Daniel Hägglund, Lars Klingström, Ola Kårén, Mats Nilsson, Olov Norgren, Lisbeth Rantaniemi, Caroline Rothpfeffer, Daniel Stridsman, Hanna Triumf, Anders Tolblad, Jeanette Tretten, Bror Österman Editor: Jeanette Tretten Photos: Bo Göran Backström, Eddie Granlund/Folio, Lars Klingström, Ola Kårén, Håkan Nordström, Erik Normark, David Rönnblom, Jonny Stenmark, Bror Österman, m fl Layout and graphic production: Energi Reklambyrå, Linköping Printer: DanagårdLITHO First edition 1997. Second edition 1999. Third edition 2007. 2011 Fourth edition 2011. Printed in 38 000 copies. English versions available for all editions. The second edition is available in Estonian, Latvian and Lithuanian.

Preservation of natural production levels. Focus on a high, sustainable and valuable wood yield. Holmen Skog is to actively manage the forest so that the forest and its products make a positive climate contribution. Holmen Skog 89180 Örnsköldsvik Telefon: 0660-37 74 00 E-post: [email protected] www.holmenskog.com

In February 2012 the Holmen Group decided on a new Group Environmental and Energy Policy. The policy can be found on www.holmen.com

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skoglig planering

skoglig planering

Contents Certification at Holmen

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Operational planning _______________________________________________________________ 26

Scheduling pre-commercial thinning _________________________________________ 58

Conservation trees, potential conservation trees and dead trees___ 84 Damage to soil and water ________________________________________________________ 86

Environmental Policy

1

Field demarcation____________________________________________________________________ 27

Species composition and prioritisation _______________________________________ 59

The Evolution of Swedish Forests and Forestry

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Seed Supply and Seedling Production

Stem types and what stem to retain and what to remove ____________ 60

Scheduling final felling ______________________________________________________________ 87

Broadleaved shelterwoods above spruce ___________________________________ 61

Monitoring and evaluation of final felling _____________________________________ 87

Origin and dynamics of the taiga ________________________________________________ 6

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High quality seeds mean future high quality timber production_____ 30

Pre-commercial thinning and conservation _________________________________ 62

From north to south __________________________________________________________________ 6

Seedling production ________________________________________________________________ 31

The start of organised forestry and the selective logging era _____________________________________________________ 7

Regeneration

Local site conditions _______________________________________________________________ 36

Thinning

The second era: end of selective logging and start of restoration ______________________________________________________________ 7

Operational planning for regeneration _______________________________________ 36

Planning for success in thinning ________________________________________________ 65

The pine weevil problem __________________________________________________________ 41

Type of thinning _______________________________________________________________________ 69

Preparatory cutting and site clearing _________________________________________ 42

Wildlife management based on fodder supply ____________________________ 90

Species composition and preferences _______________________________________ 70

Fertilisation

94

Ditching _________________________________________________________________________________ 43

Stump treatment to control root rot ___________________________________________ 71

Roads

98

Scarification ___________________________________________________________________________ 44

Logging damage _____________________________________________________________________ 72

Planting__________________________________________________________________________________ 46

Nature conservation and preservation of cultural heritage in thinning __ 73

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Direct seeding ________________________________________________________________________ 50

Monitoring and evaluation of thinning _________________________________________ 75

High conservation values in managed forest ______________________________ 12 Holmens commitment to develop high conservation values ________ 13

Inventory routines ___________________________________________________________________ 16

Seeds and seed handling ________________________________________________________ 51

Montane forests ______________________________________________________________________ 17

Spruce shelterwood ________________________________________________________________ 52

Co-existence with reindeer husbandry ______________________________________ 18

Seed trees _____________________________________________________________________________ 53

Biodiversity and cultural heritage_______________________________________________ 19

Natural inseeding ____________________________________________________________________ 53

Forests with high conservation values _______________________________________ 20

Conservation and cultural heritage ___________________________________________ 54

Natura 2000___________________________________________________________________________ 20

Monitoring and evaluation of scarification and planting _______________ 55

____________________________________________________

88

Moose and forestry __________________________________________________________________ 89

92

Present challenges _________________________________________________________________ 10

Wetlands and watercourses

64

Wildlife

Social Values of Forests

The third era: ‘new forestry’ makes its mark ________________________________ 8

Planning

34

Monitoring and evaluation of pre-commercial thinning __________________ 63

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Pre-Commercial Thinning

56

Final Felling

76

Transport

100

Machinery, lubricants and chemicals

102

Fuel, oil, lubricants and coolants _____________________________________________ 103

Planning is essential for efficient environmental care ____________________ 78

Wood Purchasing

104

Stump treatment to control root rot ___________________________________________ 78

Environmental Auditing and Monitoring and Evaluation Routines

106

Training and Competence

107

Holmen Skog

108

The Holmen Group

110

Glossary

112

Biofuel ____________________________________________________________________________________ 79 Stump harvesting ____________________________________________________________________ 80 Non-productive sites ________________________________________________________________ 80 Biotopes requiring special consideration ____________________________________ 81

Prescribed burning _________________________________________________________________ 22

Pre-commercial thinning well executed results

Archaeological and cultural heritage sites ___________________________________ 81

Multiple-use planning ______________________________________________________________ 24

in dense and vigorous stands __________________________________________________ 58

Buffer zones ____________________________________________________________________________ 82

Broadleaves ___________________________________________________________________________ 24

Planning for success in pre-commercial thinning_________________________ 58

Restrictions on size of areas clear cut ________________________________________ 83

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The Evolution of Swedish Forests and Forestry The Swedish forest is part of the European taiga – an enormous forest ecosystem ranging from the Ural Mountains deep inside Russia to the Norwegian Atlantic coast. In spite of considerable variations in climate, physical conditions and topography, the entire area features more or less the same type of forest.

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Origin and dynamics of the taiga Our part of the world has been repeatedly covered by ice, with a thickness measured in miles. The ice masses have shaped topography, rocks have been ground to till, and large masses of material have been moved around in the landscape. This explains much of the soil formations of today’s Sweden. It is not unlikely that we are currently experiencing a brief period of ‘comfort’ before the next glaciation. The last glaciation came to an end in Scandinavia some ten thousand years ago. Some scientists predict that the next glaciation will be upon us within another ten thousand years. Current climatic trends may change this, of course. What seems like eons from a human perspective is just the blink of an eye in evolutionary terms. The thousands of plant and animal species found in today’s Sweden are the result of migration after the last glaciation. This makes Northern European ecosystems young in comparison to parts of the world that were never affected by glacial ice. Our flora and fauna have developed over a long time, and have ‘emigrated’ to warmer areas during periods of glaciation, and returned when conditions have permitted. In these times of climate change, it is worth remembering that our part of the world has undergone a number of major climatic changes since the ice age. Initially, the retreating ice left harsh and cold conditions, followed by a period so warm that the broadleaved trees of southern Sweden could grow in the far north. This warm period culminated some six thousand years ago. Since then, the climate has been cooler, with numerous ups and downs. Another important factor is the fact that life in the taiga is adapted to regularly recurring natural forest fires. Studies have shown that more or less all Swedish forests have a history of fire. It has not been unusual for forest fires to rage several times in a single century. This still holds true for much of the forest of the Russian interior. This has had a profound impact on the forest landscape, creating different biotopes,


each with their own conditions and species compositions. Taiga forests differ from tropical forests in many respects. In tropical forests, many of the nutrients are stored in the trees and other plants. The reverse is true for the taiga, where most of the nutrients and minerals are found in the soil, only a small amount being stored in the trees. If the trees are removed, there are enough nutrients to permit a new crop of trees to replace the old one. Soil nutrients in combination with species adapted to recurrent disturbances make favourable conditions for forestry in the taiga forest. Timber harvesting can be said to have replaced natural disturbances, although their effects are not identical. Wild fires do differ from final felling, and there are species dependant on fires for their dispersal.

Every effort was made to secure success in regeneration. Soil would, for example, be carried to individual seedlings on rocky sites.

From north to south The forests of southern Sweden have a long history of human activity. They have been burned, grazed and have provided firewood, charcoal and timber since mediaeval times. Intensive use led to shortages of accessible wood as early as the 1700s, particularly in central Sweden with its mining industry. Organised forestry on a larger scale can be said to have started in the mid-1800s, mainly in connection to mining. AB Finspångs Styckebruk, a mining company whose forests are now owned by Holmen, was a pioneer of organised forestry in Sweden. Management prescriptions from 1868 are a worthy predecessor of today’s practices. The silvicultural system prescribed to ensure sustainability was clear felling followed by regeneration through planting. The generally held truth that the forests of northern Sweden have been unaffected by man until recently is now being modified by research results. Extensive use of forest land since the Stone Age has led to a forest landscape affected by man. Another important development that dated from the mid nineteenth-century was the large-scale logging of the forests of northern Sweden. Timber was floated to

newly-established sawmills sited on the estuaries of the main rivers. Within a few decades, the sawmills had become a major Swedish industry. This type of forestry was selective and purely exploitative, often referred to as ‘timber-cruising’ or diameter limit felling. Forests were not clear felled, only the valuable timber trees were harvested. Area by area was drained of timber trees, of sizes rarely encountered today. What remained was sparse and poorly regenerated forest, to a degree never previously experienced in Sweden. Unlogged remnants of these forests are found along the mountain range of the interior north, and large areas enjoy protection.

The start of organised forestry and the selective logging era

This is what Sweden may have looked like some 10 000 years ago. Perito Mureno, Argentina.

Wild fires were a natural and common feature in Sweden’s original forests. Recurrent fires chiselled out different biotopes, each with their own conditions and species compositions. Kolmården, Östergötland.

At the start of the twentieth century, the winds of change started to blow through Sweden’s forest industry. It was realised that harvest regulation and active regeneration were essential if forestry was to survive as a major industrial sector. This resulted in the passing of the Swedish Forestry Act, in 1903. The Act stipulated that forests cut were to be regenerated. With forestry of German influence single tree selective logging dominated. These methods were eventually deemed inappropriate for Sweden’s harsher climate. They resulted in sparse and inadequately regenerated forests of low value, featuring stands in which growth was also more or less retarded. This selective system had proved effective in more southerly European climates, but not in Sweden’s harsher conditions.

The ecological effects of selective cutting in Sweden were however modest. Cutting and extracting selected trees ensured that variation in age and higth were largely maintained. Red-listed fungi and lichens have been found in forests that were selectively logged in the 1930s and 1940s. Inadequate and unsuccessful regeneration practices in the first half of the twentieth century however caused a problem that is still felt, the skewed age distribution. A factor important for the forest dynamics of the early 1900s was grazing. Grazing on forest land has a very long history in Sweden. Grazers included cows, sheep, goats and horses. Grazing on forest land ceased during the 1920s to the 1940s. Forests clear felled today have often been formed by repeated exploitive cutting and grazing.

The second era: end of selective logging and start of restoration Selective logging sparked an intensive debate that resulted in the introduction of the clear felling system at the end of the 1940s. An era of restoration commenced. Sparsely stocked stands were felled first to permit denser stands to recover and grow on their own. Old and sparse stands were to be replaced with young, well-tended and fast growing forests. Regeneration through direct seeding and planting gained ground. Research and tree improvement progressed and nurseries were established all over the country. General working conditions improved in the forest sector. Working environment, improved safety, ergonomics and nutrition came into focus.

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Fire dynamics still prevail in the natural taiga forests of interior Russia. Light green parts of the picture are dominated by broadleaves, indicating a fairly recent fire. Low lying moist stretches and areas around swamps have remained untouched by fire, allowing for spruce dominance. Petjora Illytj, Komi, Russia.

The chainsaw was introduced in the 1950s and soon dominated felling work. Logging operations started to be mechanised on a large scale, and extraction with horses was phased out. Operational economics dictated that felling sites had to be large. Clear felling tended to clear sites properly of trees in those days. Felling was followed by site clearing to ensure that no trees at all remained. Large scale operations meant large scale silviculture. Blanket treatments were favoured regardless of local variation. Conservation aspects started to make their mark in the 1980s. This was partly a response to the very uniform forest management with large felling operations and blanket treatments that were in force. In 1985 Holmen issued its first publication on more modern conservation methods. Conservation however has a longer history at Holmen.

The third era: ‘new forestry’ makes its mark SForest science continued to make progress. A new site classification, based on local conditions described through vegetation types and soil characteristics, was adopted. Forestry adapted to site conditions was accepted as a goal.

All of this meant that conservation gained acceptance as an integral part of forest management. Rarer stand characteristics and components were now regarded as worthy of preservation over rotations. Sallow, aspen, very old trees and dead trees were preserved in the early 1990s. Areas important to biodiversity were identified, so-called key biotopes. Redlisted species were permitted to make their mark on forest management. Seasoned forest officers found themselves sitting in classrooms. Customer groups insisted that forestry should clean up its environmental act. Holmen adopted a silvicultural policy in tune with the new times in 1992. New and improved practices lead to FSC® certification for Holmen in 1998, and PEFC certification five years later. As specified by the Swedish certification standards, Holmen offers complete protection to 5% of its productive forest area – at present some 50 000 hectares distributed over 14 000 locations all over the Sweden. The size of the locations varies from a couple to hundreds of hectares. In addition to these areas Holmen protects buffer zones, micro-biotopes, groups of trees and single trees as part of its daily forest management. In total some 10% of the productive forest area owned by Holmen is under protection. To that should be added some 230 000 hectares of unmanaged and often sparsely

In the early 1990s blanket clear felling was replaced by a more environmentally friendly and flexible approach. The virgin forest was a source of inspiration. Note how similar the landscape is to the Russian taiga, illustrated on the preceding page. Buffer zones and protected solitary trees were introduced. Buffer zones are more functional nowadays and not necessarily as wide as shown here. Korpåsen, Hälsingland.

stocked swamp and rocky areas that are also part of Holmen’s forest estate. Forests are part of the solution in combating climate change. Forests provide raw material and bio-energy without releasing new amounts of carbon dioxide. Wood could replace material and energy sources that are less climate friendly. Demand for forest fibre is on the increase, from processing industry as well as the energy sector. Increasing annual cuts while preserving biodiversity is a worthy challenge for today’s forestry. It is imperative that growth rates are increased on Holmen’s forest land. An investigation conducted by Holmen together with the Forest Research Institute of Sweden shows that growth can be increased by some 25% across Holmen’s forests, using methods now at our disposal. It is not unlikely that research could raise the potential further.

Post WWII felling sites were often large and conservation measures, at best, modest. From a wood production point of view they must be deemed successful. These sites make up much of the forests thinned today.

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There is every chance that the challenge of combining wood production, nature conservation and social values will be met with success. Sveg, Härjedalen.

Present challenges There are some 300 000 forest owners in Sweden managing their forests according to their own heads, under restrictions imposed by legislation and, for those who choose so, certification standards. This creates a ‘management mosaic’ in the Swedish forest landscape. Swedish forests grow under a wide variety of conditions. There are no two places with identical conditions. This has led to management practices rather unique to the country, with wood production and conservation interacting on a different scale. More active forest management, cutting of the last forest areas creamed off in the late 1800s/early 1900s combined with possible climate changes will increase the focus on conservation values of our forests. The answer to this challenge may actually be to elaborate the Swedish model as described above. There is every possibility of preserving biodiversity by this approach. When looking back at our forest history, there is no shortage of mistakes and misuse. Despite that, there has been no major ecological havoc in our forests. The main reason is the resilience of the Swedish forest ecosystem to various kinds of disturbances. The increased commitment to conservation that commenced in the 1990s is now evident from data from the National Forest Survey. There are now more very large trees

and deciduous forests and dead wood in our forests. These are factors deemed important to biodiversity. Stocking in general has been on the increase for a long time. This in itself creates a larger variation in conditions. We are happy to note general increases in populations of forest-dwelling birds and mammals. Our long history of forest management means that there is hardly any virgin forest left. On the other hand our forests bear little resemblance to fast growing plantations. Our forest can be labelled semi-natural with many natural processes intact, but with changes in structures and functioning. The Swedish model for conservation, which also incorporates protection of publicly owned areas, has created an impressive network of protected areas in the form of national parks, reserves, voluntary set-asides and tailored prescriptions for all operation sites. This network can be further improved by actively creating habitats and substrates of importance. Conservation should be developed in terms of quality rather than quantity. Holmen is committed to the Swedish model and to its improvement. This is an area with much potential for development and creativity. The road forward is more apparent for improved wood production. Tree improvement and improved regeneration methods are still the areas in focus.

Holmen’s set-asides. Green: Holmen’s forest. Grey: Impediment. Red: Set-asides

It should be no surprise that we end up with the kind of forest we decide to create. Research will help identify structures and other phenomena of importance to biodiversity. Dead wood is an important habitat to half of all forest dwelling species. Important biotopes and structures can be favoured and/or created by present forest management practices. This is a most complex challenge where help from research is needed. Use can be made of fire, water, improved planning and modern technology. Large areas have been set aside for conservation. Many of them benefit from undisturbed development. There are however areas whose value would benefit from active management. There are ongoing field trials aimed at actively recreating conservation values. This is part of a research programme by the name of ‘Future Forest’. The programme is partly financed by Holmen. Thinning is a treatment that can be improved from a conservation standpoint. Edge zones and selected groups of trees can be actively preserved in thinning and final felling. These are examples of ambitions built into Holmen’s silvicultural policy that will be communicated in this booklet.

Protection of forest land 4.5 million hectares in Sweden 2 million hectares of productive forest set aside for conservation

of non-productive forest enjoy full protection

21.2 million hectares of productive forest land under active management

Source: The Swedish Forest Industries 2010, facts and figures.

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High conservation values in managed forest


Holmens commitment to develop high conservation values The diagrams show the development of forests from different periods of time, and how age distribution develops in our estimation of potential cut.

Proportion of the total productive forest Proportion of the total productive forest

Year 2010 14 %

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Year 2010 Proportion of the total productive forest

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Historical maps let us follow the village of Tjuttorp since 1793. AB Finspångs Styckebruk acquired the land in 1881. All forest land was clear felled in 20 years. Regeneration work was completed some years after. The forests were thinned in 1927–1928, and in the 1940s. Today there are mature forests. Despite the few conservation measures taken, the area today is of high conservation value. Parts of it are included in the Holmen archipelago of voluntary set-asides. Tjuttorp, Östergötland.

14% 12% 10% 8% 6% 4% 2% 0%

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Purple: Conservation policy of today. Purple age classes represent forests treated according to today’s standards (since about 1990). Site-tailored prescriptions will, with time, increase in importance. Edge zones, preserved tree groups and single trees will in a hundred years stand out much more and contribute to landscape beautification. Site tailoring accounts for 7% of the area treated in a full rotation (about a hundred years). Holmen intends to further develop and modify conservation measures in connection to final felling and management of buffer zones and protected tree groups.

Grey: Earlier overlogged mature forests. The grey age classes represent forests formed between 1890 and 1940. These stands have been subjected to a rich variation of use. Many of them have been completely denuded of trees, or almost so, not unlike today’s final felling, while others have been fairly well stocked. This is a category of stands that are harvested today. Preservation of conservation values at these sites has the highest priority. Existing conservation values shall be lifted over to the next generation (in the purple bars).

Blue: Clear felled between 1950 and 1990 with some conservation measures. The blue age classes represent forests created from WWII to around 1990. In those days clear felling truly meant clear felling. Forests that followed are evenly aged and uniform. What variation there is, tends to stem from nonbiotic factors like hydrology, topography and rockiness. Improving nature values on these sites has the highest priority now.

Green: Voluntary set-asides (5%). The green forests represent voluntary set-asides made by Holmen. They cover some 5% of Holmen’s productive forest. The conservation value of some of the areas would benefit from active management, thereby increasing their contribution to the preservation of biodiversity at landscape level.

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Planning Planning has the highest priority in Holmen’s forest management. A complete field inventory of the forests is made every ten years. The results are then used in the estimate of potential cut. The estimate has a planning horizon of a hundred years, and is a foundation for operational planning, conservation and social and cultural considerations. Planning routines ensure that cutting rates are maintained and that silvicultural treatments are timely and appropriate. Conservation and commitment to social and cultural values need thorough planning to be efficient. Clear directives are needed for activities to follow guidelines adopted.

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planning

Planning

Montane forests are handled separately as specified by the FSC® standard, Borgafjäll, Västerbotten.

Miriam Nordh assesses the need for pre-commercial thinning from a helicopter. Mikkelsträsk, Västerbotten.

Inventory routines Since the mid-1800s, decisions concerning forest management policy and appropriate cutting levels have relied on forest surveys. In the late 1940s, statistically sound and regular inventory routines replaced the previously rather crude harvesting plans. Since then, Holmen’s forest assets have been inventoried approximately every ten years. The latest complete survey was conducted in the year 2010. Stocking has generally been found to be on the increase, as have growth rates. After the census follows an estimation of potential cut with a 100 year scope. Cutting rates decided upon have far reaching consequences for the development of the resource. High quality digital maps and stand descriptions using relevant variables form the foundation for planning of harvesting and silviculture. Holmen has 170 000 individual stands identified and described in its catalogue. The catalogue is computerised and connected to a geographical information

Montane forests system (GIS). There are routines for regular updating of the stand catalogue. New techniques to ensure a high quality stand catalogue are regularly considered.

Guidelines for inventories and estimation of potential cut

Category 1 Virgin-type forests, specifically in montane areas, defined as follows: – Few or no stumps of felled trees – At least 15 to 20 large fallen trees per hectare – An abundance of wood-living fungi – Plenty of natural stumps and dead standing trees – Uneven-aged and fully stratified forests

Holmen’s forest assets are surveyed every ten years. Statistically sound methods are required and all relevant data are to be collected. Inventory results and data in the stand catalogue form the basis for predictions and estimation of potential cut, with a scope of 100 years. Relevant thematic maps to illustrate cut estimations are to be available for all districts. Nature and culture conservation requirements should be taken into account when estimating the potential cut.

A harsh climate and broken terrain are typical of Swedish montane forests. These forests differ from other inland forests in several respects. They have been less affected by industrial forestry than other forests. In nature conservation terms, they are highly valuable, and they are important to reindeer herders. Evidence of human activity is most evident close to rivers and other major watercourses, diminishing as one nears the upper limits of productive forest land. Forestry is a major source of income for many of those who live in montane areas. Montane areas are sparsely populated and employment opportunities few, making forestry all the more important. Large areas of montane forest have been set aside as protected areas. Parts of the area can however be used without jeopardising conservation values and their value for reindeer herding. The definitions and guidelines below apply to areas above the Nature Conservation Limit as defined by the Swedish Society for Nature Conservation (SSNC), subject to local variation after agreement with the SSNC.

Holmen forest maps are continuously updated. They are based on high resolution digital rectified photos.

Category 2 Other forests with considerable natural values, defined as follows: – Evidence of previous selective logging – Few fallen dead trees – Limited incidence of wood-living fungi – Normally uneven-aged and fully stratified forests – Scattered dead standing trees Category 3 Areas not belonging to Category 1 or 2. Typically, these are stands with a recent history of forest management, which has had a major impact.

Guidelines for Montane Forests Forests belonging to Category 1 are protected. The only permitted measures concern the conservation or improvement of natural biodiversity. Category 2 forests, located in strips or enclaves adjacent to virgin-type forest areas, creating a unified whole with these areas, are also protected under the same rules applied to Category 1 forests Other Category 2 forests can be logged using selective cutting forestry methods, taking great care to promote natural values. Category 3 forests should be managed according to normal Holmen standards.

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Planning

Planning

Biodiversity and cultural heritage As the share of old forest shrinks in the forest landscape, establishing correct conservation priorities becomes increasingly important. Many species are able to adapt to change and to persevere in cultivated forest, provided that conservation is properly planned. Other species require land that remains undisturbed. Consequently, Holmen needs as comprehensive a picture as possible of the natural and cultural values within its forests. There are areas where biodiversity can be favoured by active management, and there are areas where management is necessary for biodiversity. A key biotope is a biotope judged to be particularly important for fauna and flora. Red-listed species are generally, but not necessarily, found or expected to be found. Judgement is also based on structures, species composition, history and physical environment. Holmen uses methods developed by Skogsbiologerna, a Swedish company working in nature conservation, to assess conservation value at site level.

In most of the northern Holmen forests, forestry co-exists with reindeer husbandry. On patrol, headed up into the mountains for calving with Ruvhten Seijte Sami community, Härjedalen.

Age of an old pine in a protected area is determined. Göran Johansson, Finspång, Östergötland.

Co-existence with reindeer husbandry Reindeer husbandry and forestry are practised in more or less the same areas, from northern Dalarna to the far north. Forestry and reindeer husbandry both benefit from a mutual understanding of each other’s respective needs. The Swedish Forestry Act and certification standards (FSC®) specify that

Guidelines for forestry and reindeer husbandry Reindeer husbandry should be shown due regard, as specified in sections 20, 21 and 31 of the Swedish Forestry Act. Timing of consultation meetings should be mutually agreed upon. Maps of operational plans should be provided to the Sami community well in advance of consultative meetings. Planning documents from Sami communities concerned should be acquired. Where areas of particular importance to the Sami community are involved, stand maps should always be attached to the operational maps.

Minutes should be recorded for each meeting. These minutes should define measures to be implemented and areas discussed, points of agreement and dis- agreement. Considerations and restrictions agreed upon should be recorded in the stand catalogue.

The minutes should be ratified by the parties con cerned. Restrictions agreed on should be documented.

Edges of swamps and streams, old trees or groups of old trees often host lichens important to reindeer husbandry. Special attention should be paid to such areas close to cutting sites. Major occurrence of lichen of importance to reindeer husbandry should be documented in the stand catalogue.

Scarification should, unless something else has been agreed upon, guarantee sufficient quality and be done as gently as possible to lichen types, lichen-rich types and dry-berry types affected by lichen.

Key biotopes are totally protected from commercial forestry, they may be managed, but only to improve conservation values.

Places of cultural heritage for the Sami people should be awarded special consideration. The same applies to sites with an important role in reindeer husbandry. Examples of such sites include old settlements, calving grounds for reindeer, migratory routes, night shelter sites, areas with an abundance of hanging lichen, heritage sites and sacred sites.

5% of the productive forest in each Holmen region should be protected. Key biotopes and protected zones surrounding them are included in the target. In regions where this target has not been reached and where key biotopes comprise less than 5% of Holmen’s productive forest land, the following areas should also be awarded high priority:

– Areas with the potential to develop into key biotopes. – Zones around areas of high nature value. – Wider buffer zones surrounding major water courses, where protection is justified from a con servation standpoint by conservation concerns. Detailed concerns as specified in the Swedish Forestry Act or by the FSC® or PEFC are not included in the 5% target.

Prescribed burning should not be performed in areas important to reindeer husbandry.

and cultural heritage

Holmen should have as complete a picture as possible of the natural values and cultural heritage sites in its forests.

Holmen is obliged to consult with concerned Sami communities when planning final fellings, silvicultural activities following final felling, fertilisation and construction of logging roads.

Guidelines for natural values

Identified key biotopes and other areas of high natural value should be mapped and registered in the stand catalogue.

A rock barrier along a timber-floating route is a good example of hard labour and workmanship of yesteryear. Faxälven, Västernorrland.

Known occurrence of red-listed species and indicator species should be documented in the stand catalogue. Assessment of nature values should be routinely conducted in conjunction with area planning, except in the case of obviously plain forests.

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20

Planning

Planning

Forests with high conservation values Forests with high conservation values are forests classified by the Swedish Environmental Protection Agency as objects of national interest. These forests typically have an abundance of key biotopes and red-listed species. Montane forests of Category 1 and 2 are normally considered to have high conservation values. These forests should be included in Holmen’s voluntary set-asides.

Natura 2000 Natura 2000 is a European initiative to conserve biodiversity in the form of species and habitats. Many Natura 2000 areas will become nature reserves. The Natura 2000 network, EU directives on species and habitat conservation and the directive on bird presentation lay the foundation for how regional authorities work with Natura 2000. No treatment or felling that might jeopardise nature values may be conducted in Natura 2000 specified areas without the permission of regional authorities. Most forestry activities require such permission, which may even be required for activities outside these areas. The Swedish Forest Agency is the issuing authority for such permits, as well as determining which measures require permits. Natura 2000 areas are included in Holmen’s GIS routines. Data is updated annually.

Guidelines for Natura 2000 All activities planned for Natura 2000 areas are reported in advance to the Swedish Forest Agency. Holmen will seek compensation in cases where Natura 2000 restrictions significantly hamper forest management.

Olov Norgren and Anna Bylund inspect a Vattendragen ärrestored viktiga för water passage in Rödvattensskogarnas biologiska mångfald. bäcken, Fiskån Västernorrland. strax innan dess utlopp An arch secures waterJämtland. passage i Östra Fiskåvattnet, with minimum disturbance of the aquatic environment.

Wetlands and watercourses Ditching and draining in the past has reduced the number of wetlands in Holmen’s forest assets. In the past, areas were ditched for agriculture and to increase productive forest, particularly for Holmen Skog in the coastal area of West Bothnia. To accommodate timber-floating, smaller watercourses were straightened and cleared. Extensive road construction also affected many watercourses, creating obstacles for fish and other aquatic organisms because of poor culvert designs. Wetlands are important. They function like sponges, maintaining a hydrological balance. Water is further filtered as it passes through wetlands. A host of species, notably birds, depend on the special habitat provided by wetlands. Major efforts to map and upgrade culverts along Holmen’s road network are under way. Poorly constructed culverts prevent free movement of aquatic fauna and flora. Free passage will be secured particularly in valuable watercourses, for example those with trout populations. There are also efforts to restore wetlands, typically including active treatment to conserve/increase biodiversity. The effects of these efforts are obvious even to untrained eyes.

Holmen cooperates with the Swedish Wetlands Foundation on wetlands restoration.

Guidelines for wetlands and watercourses All regions should have a plan to replace all culverts hindering movement of aquatic fauna. Special management and treatments required for watercourses and wetlands with high conservation values should be recorded in the regional conservation plans.

Watercourses are important to biodiversity. Artificially established wetland at Tegnetorp, Östergötland.

The freshwater pearl mussel is red-listed and dependent on trout for its reproduction.

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22

Planning

Planning

Guidelines

for safety precautions in connection to prescribed burning

All districts should appoint a staff member responsible for prescribed burning and for contacts with the fire service.

Every district should have a list of staff that is submitted to the local fire service.

Every district should have a list of staff prepared to report for duty at short notice. Remuneration issues have been sorted out for everybody on the list.

Fire fighting equipment should be readily avail able and ready for use.

Prescribed burning is an impressive sight. Kolmården, Östergötland.

Burning fertile and moist land creates a habitat now rarely found in Sweden, the broadleaved succession. Kolmården, Östergötland.

Prescribed burning Fire has historically been the most common natural disturbance in Sweden’s forests. Fire has many ecological functions. A large number of fungi and insects are more or less dependent on fire and burnt substrates for some survival. Seeds from some plants can lie dormant in the soil for decades, germinating only after fire. The ashes generated by fire raise soil pH values and reduce allelopathic substances hampering germination of seeds and growth of seedlings. Prescribed burning is part of certified forestry practices. Special care should be taken to ensure that maximum biological benefits of the treatment are obtained. Prescribed burning is one of the main treatments done to promote biodiversity in Holmen’s forests. Sometimes burning is preceded by thinning to enhance the effects of burning.

Guidelines for fire and prescribed burning No burning is to be carried out in areas important to reindeer husbandry. Prescribed burning is to increase to favour fire-dependent flora and fauna.

Over a five year perspective it is anticipated that every region will have taken measures needed to carry out prescribed burning in an area corresponding to at least 5% of the dry and mesic area to be regenerated. Wild fires can be included in the area target. Practical considerations, for example proximity to human settlements and weather conditions, might limit the scope for reaching the 5% target. The amount of wood retained on sites treated can be used to compensate for this. A procedure has been agreed on with the FSC ®, see below. Measure 15% of original volume retained 30% of original volume retained Prescribed burning in designated areas

Area factor 1.5 2 3

Previously burnt areas should be given priority when selecting areas for burning. Dry and poor sites with thin humus layers should not be burnt. Final felling carried out prior to prescribed burning is subject to the same set of guidelines as other sites. This means that protective zones and protected trees are to be selected and preserved. Snags, however, need not be cut. Extra care should be taken on sites to be burnt, to ensure maximum benefit from the treatment. Burning should be implemented in a manner to ensure that fire-dependent species really benefit, for example through thorough burning of the humus layer. Further, a considerable number of the trees should die or be seriously fire-damaged when protected areas are burnt. Prescribed burning can be carried out on all sites. The treatment needs to be recorded in the planning routines and registered in the stand catalogue.

The burned forest is an excellent habitat for reproduction of some woodliving species, which in turn provide a virtual buffet for woodpeckers. Kolmården, Östergötland.

Fire always poses a safety risk. It is important that staff engaged in burning activities are adequately trained and equipped.

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24

Planning

Planning

New areas can be selected following a joint assessment, in conjunction with the update of conservation plans. These decisions aim to maximise conservation values in such selected areas. In compliance with our certification standard, one protected area may be exchanged for another, provided it possesses higher natural values. Conservation values of the areas set aside are thus expected to increase over time. Holmen conservation planning aims to: – Achieve a landscape-based perspective concerning natural and cultural values in each district. – Set priorities that generate the highest possible conservation benefit. – Provide data for felling estimates that take account of local conditions. – Assist staff involved in external communication. – Improve our understanding of conservation work, and improve conservation efforts even in a landscape perspective.

Broadleaves

During most of the rotation broadleaved trees should predominate in at least 5% of mesic and moist forest. Delsbo, Hälsingland.

Multiple-use planning The long-term survival of naturally occurring species and animals should be secured. This requires the continued survival of a variety of valuable biotopes. Some of these valuable biotopes have been formed by fire. These cannot be conserved, but must be created. Many species also require several kinds of biotopes for their continued survival. Nature values and cultural heritage sites should be registered in special multiple-use forestry plans. Aquatic environments are included in this. In areas where reindeer husbandry is practised, places of special importance or cultural value should be documented. This also includes assessments to determine which elements are partially or totally absent from today’s forest landscape. Conservation values are maintained or enhanced through re-creation of rare habitats. Each district is responsible for setting up and/or regularly updating multiple use plans as needed. These plans cover the entire Holmen forest.

Broadleaves occur mainly in scattered groups in coniferous forests, typically along watercourses, wet hollows and lakes, and also as new growth after a forest fire. Broadleaves provide habitats for many insects and, consequently, insect-eating birds. Woodpeckers use broadleaved trees for their nests. Old and large broadleaved trees host scores of specialised species of mosses, lichen and fungi. The northern regions of Holmen stopped using herbicides to control broadleaves in the early 1960s. Management practices were tolerant to broadleaves compared to what was normal in Sweden at the time. Broadleaves are on the increase in Holmen’s forests. They account for 14% of the volume in the north, and 9% in the south. Almost 4% of the Holmen forest area is dominated by broadleaves.

Guidelines for broadleaved forests Areas dominated by broadleaves should increase to favour flora and fauna dependent on broadleaved trees and forests. Broadleaved species should predominate in at least 5% of mesic and moist forest, for most of the rotation cycle. Broadleaved forests that are already protected may be included in this 5% goal. Areas difficult to regenerate with conifers should be given priority when creating new broadleaved stands. Areas of interest include moist sites or burnt areas, featuring abundant natural regeneration of broadleaves.

Broadleaved stands are stands in their own right, treated accordingly in the stand catalogue. Stands of broadleaves are cleaned and thinned so that flora and fauna dependent on broadleaves are favoured. Dead and dying trees are not to be removed.

Pines deliberately damaged when creating gaps. The objective is to regenerate aspen, and to protect from moose browsing by a ‘wall’ of pushed over trees. Storskogsberget, Västerbotten.

Creation of dead wood in a rich riparian area. Storskogsberget, Västerbotten.

Guidelines for multiple-use forestry plans Multiple-use plans are part of the Holmen GIS system. These plans are available to the general public via the Holmen website and/or through contact with the relevant district staff. Districts assign responsibility for the plan to a specific staff member. The person appointed should be qualified in conservation biology. These plans are updated every five years to ensure that priorities are correctly set; ensuring that the areas protected are the areas of highest natural value. This is normally done through setting aside areas with documented conservation values. When updating plans, management regimes should be prescribed for larger areas set aside for protection. High conservation value areas should be permitted to develop without human interference, except for treatments deemed necessary to preserve their value.

Protected areas that lack the highest conservation values may be suited for management to enhance their value(s). Such areas may benefit from active management to enhance their value. This applies to buffer zones and areas surrounding key biotopes as well. Holmen gives high priority to areas that have a long history of management, such areas typically have few protected areas. There are however areas that can develop higher values through active management. Planning should include treatments to enhance the conservation value of these areas.

The fact that a stand is treated to enhance conservation value does not mean that timber yields from the operations cannot be utilised. Examples of this include creation of glades and liberation of trees to be retained. Moreover, trees can be deliberately pushed over or damaged by harvesters to create dead trees or slow growing and not too vital trees that are much appreciated by wildlife. Management of stands under protection should be done only after consulting staff members responsible for the multiple-use plan. Should key biotopes come into question, local forest authorities should also be consulted.

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Planning

Planning

Operational planning The Holmen operational planning routine (TP) is a powerful planning tool for site-adapted forestry and nature conservation. TP enables the generation of specific site-adapted guidelines on Holmen-owned forests as well as on areas from which Holmen secures timber. Digital directives and operational guidelines are produced using TP. Operational planning is essential for efficiency and for the control of soil damage and other mishaps. TP routines provide – Readiness for accidents through establishing workplace coordinates. – Well planned logging, conservation, silviculture and timber transports. – Comprehensive operational site directives. – Digital maps where it is possible to determine areas to be treated by means of GPS coordinates and to calculate areas treated with high accuracy. – Electronic reporting of scheduled final felling to the Swedish Forest Agency. – Documents and sketches for digital handling or to be printed on paper. – High degree of flexibility through a bank of pre-planned treatment sites. – Due regard, properly documented, given to reindeer husbandry.

Guidelines for operational planning TP is routinely used in planning felling and silvicultural operations.

Field demarcation well executed means that mishaps can be avoided. Johan Karpholm, Vimmerby, Småland.

Field demarcation

Planning is to follow standards available on the Holmen intranet.

There are operational site boundaries that are not obvious to the eye. They need to be precisely marked in the field. Standards have been developed for demarcation. A protected zone is an example of an area that needs to be carefully demarcated. Other examples are stream crossings and key biotopes. The general Holmen standards for demarcation of boundaries are found below; there may be local variation.

Comprehensive plans shall be drafted for each area. A supply of pre-planned operational sites covering two years of operations should normally be available at each district.

Operational planning is a skilled task. The objective is to find the best balance between industrial wood production, conservation and economy. Göran Johansson, Finspång, Östergötland.

Type

Colour

Logotype

Text

Estate boundary

Yellow & red

HOLMEN

–

Main road, stream crossing

Blue & orange

HOLMEN

–

Silvicultural treatments

White & orange

HOLMEN

–

Protected areas (including wells)

Blue, white & red

HOLMEN

NATURHÄNSYN

Protected heritage sites

Yellow & black

HOLMEN

KULTURHÄNSYN

Hunting

Orange & moose profile

HOLMEN

JAKT (+ moose bull in black)

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Seed Supply and Seedling Production Holmen sources its forest seeds from its numerous seed orchards. The orchards supply seeds of high genetic and physiological quality. Seeds are also bought from external sources. In times of seed shortages, cones can be collected in selected areas. Cones collected in orchards are treated in a seed extractor. The cones are heated in a process where moisture is carefully controlled. Finally the cones are opened and their seeds collected. After that follows water dewinging at a special facility run by the Forestry Research Institute of Sweden. Dewinging is done in a way that enhances seed quality, making it fit for practical regeneration work. Seed properties are crucial for future wood production, regardless of whether the seed is to be used for direct seeding or seedling production in a nursery. Holmen has the ambition to produce top quality seedlings at competitive prices. Current (2011) seedling production is 35 million per year. Seedlings are raised in a container, developed by Holmen, called Starpot. Containers come in three sizes, 50, 90 or 120 cm3.

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S e e d S u p p ly a n d S e e d l i n g P r o d u c t i o n

Hormonal treatment to stimulate flowering in a spruce seed orchard. Sara Abrahamsson, Domsjöänget, Västernorrland.


Cones are harvested before they open up. Gnarp, Hälsingland. Holmen greenhouses are used for three batches per year, and provide favourable conditions for germination and early growth. Gideå, Västernorrland.

High quality seeds mean future high quality timber production Genetic tree improvement is the single most important tool to raise production levels in Holmen’s forests. Seeds from selected trees are raised in seed orchards. The orchards are a source of hardy seeds of high genetic potential. Genetic improvement is a rather uncomplicated and environmentally friendly way of increasing productivity. An estimate from the Forestry Research Institute of Sweden suggests that the cost of a genetically improved cubic metre is less than EUR 0.1. Seed quality is mostly specified as germinability (share of seeds that germinate per batch) and germinative energy (meaning the time required for germination). Both measures are important for results in nurseries and direct seeding. Seeds from orchards are generally better than wild seeds, genetically as well as in vigour, raising future production considerably. It is Holmen’s policy to use seeds from orchards to the extent possible, in nurseries as well as in direct seeding. Selecting seeds from the best trees in pine orchards can increase genetic gain from 12% to 17% in volume production. Lodgepole pine seeds are sourced through harvesting cones from young stands in Sweden of known origin. Pine seedlings in Holmen nurseries are exclusively raised from orchards seeds. Direct seeding is done using a mix of ¼ orchard seeds and ¾ wild seeds. This enables dense seeding and wide dispersal of orchard seeds. Supply of spruce seeds from orchards does not permit this approach. Seedling pro-

Seedling production duction of spruce is done using 80% orchard seeds, with an allowance for variation between single years. Natural migration of tree species and the harsh climate conditions prevalent in Sweden necessitate regulations on seed use, so-called provenance movement regulations. The provenance regulations should be strictly followed to ensure high seedling survival rate and sound development. It is particularly important to respect regulations in northern Sweden.

Guidelines for seed supply The seed store should be optimised in line with a predetermined ‘target’ store, subject to revision every five years. The share of orchard seeds used in nurseries and for direct seeding should be increased through investment in orchards and external sourcing of orchard seeds. Selective harvest in pine seed orchards. Seeds for use in harsh conditions or of unclear origin should be freeze-tested, to establish where they can be used.

Procedures for provenance dissemination should be observed.

It is Holmen’s goal to produce the best seedlings available in Sweden at a competitive price. Quality in seedling production is expressed in terms of the root/shoot ratio, seedling height, diameter at base and dry weight. Nutritional levels of nitrogen, phosphorus and potassium are also of great importance. Other factors include seedling vigour, the presence/absence of injury and results from test at nurseries. Holmen has two nurseries, Friggesund and Gideå. Total production is around 35 million seedlings per year. Seedlings are raised in the Holmen-developed Starpot container, produced in three sizes: 50, 90 and 120 cm3. After germination and initial growth in greenhouses, seedlings are moved into the open. The 12 greenhouses are used for three seedling batches per year. The first batch of high quality seeds is seeded in January or February. Seedlings are watered in April and raised inside the nursery until early June. Thereafter they are moved outdoors throughout the summer, and finally delivered for planting in early autumn or the following spring. As the first batch is transferred outdoors, the second batch is watered up, and transferred outdoors in June/July. The third batch is inside the nursery during August. Batch two and three need to be raised outdoors the following year to reach desired sizes. Both nurseries have facilities to manipulate light conditions, thus enabling Holmen to determine seedling size, appearance and vigour. Pine seedlings are subjected to ‘long

night treatments’ in June. Seedlings develop double needles and a bigger diameter at the stem base. Spruce is subjected to ‘long nights’ starting in July. This stimulates the formation of buds, ensures uniform height development and helps seedlings adapt to winter. Seedlings are not kept in the open during winter due to the risk of frost damage to the roots. Seedlings spend the winter in cold or freezer storage. Seedlings are protected using a combination of fungicides and herbicides, and fertilised with nitrogen and mineral nutrients. Holmen has actively supported a new nitrogen fertilisation technique for nurseries based on arginine, an amino acid. The fertiliser is commercially known as ArGrow. ArGrow improves seedling establishment in the forest through more fine roots with better water- and nutrient uptake. Arginine is stored in the seedling substrate, thus following the seedling to the planting site. Seedling survival is improved through better resilience to drought stress and higher growth rate. The environment in the nursery is improved by ArGrow, since nitrogen leakage is drastically reduced. Improvement of irrigation regimes is made possible as fertilisation is done less frequently regardless of precipitation. To detect deficient seedling batches before they leave the nursery, Holmen has, together with the Forestry Research Institute of Sweden, developed a set of tests to secure high seedling quality. The tests evaluate 28 parameters connected to seedling vigour and growth capacity.

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Average seedling height desired per seedling type.

Pine/lodgepole pine

Goal

Acceptable height variation

Starpot 50

10 cm

(7–13 cm)

Starpot 90

13 cm

(9–17 cm)

Starpot 120

17 cm

(13–21 cm)

Spruce

Starpot 50

14 cm

(10–18 cm)

Starpot 90

17 cm

(12–22 cm)

Starpot 120

24 cm

(20–30 cm)

Seedlings are transferred outdoors for further development during the growth season after an initial period in a greenhouse. Winter storage is done in large coolers or freezers. Gideå, Västernorrland.

Guidelines for seedling production Average height per seedling type is specified above. For batches that deviate from the desired heights, the district concerned should be contacted for a discussion on whether the seedlings are acceptable for planting. Root/shoot ratio should be at least 0.3. Nitrogen should account for 1.9 to 2.5% of total seedling weight. Seedling quality is determined through a set of tests in February to March. Seedlings good enough for planting should be able to withstand pulling. Seedling cases with up to 10% empty pots/poor quality seedlings are accepted. Invoicing is based on the number of seedlings actually delivered. Only legally permitted chemicals are used. Application and handling of chemicals is regulated to ensure that nursery staff are protected from direct exposure, and to prevent spillage. The level of residual chemicals should be within the range specified by the Swedish Chemicals Agency. Water used to clean chemical containers and drums and other toxic waste should be disposed of by authorised companies. Use ArGrow as fertiliser to reduce nitrogen leaching. The regular test programme, encompassing two tests per year, determines whether there are pollutants in the groundwater that originate from Holmen nurseries.

An example of a vigorous, well-nourished seedling with a sound root/shoot ratio provides for good establishment and growth after planting. The seedling is from the Gideå nursery and shows a sound root development after only a week in the field. Bågede, Jämtland.

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Regeneration Adequate planning and high quality seeds and seedlings determine success or failure in regeneration work. A number of treatments/measures need to be combined to achieve favourable growth conditions and a satisfactory result.

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R e g e n e r at i o n


Growth conditions vary in the landscape; soil types and moisture classes are typical factors separating sites. Gideå, Västernorrland.

Local site conditions Local site conditions determine choice of species and regeneration method. Adaptation to local site conditions can be said to govern regeneration at Holmen. If well done, regeneration ensures high seedling survival, and well stocked and productive young stands, low costs over time and future timber value. Planting and direct seeding dominate regeneration work at Holmen. Seed trees and shelterwood for spruce are used sparingly and only on sites obviously suited for them. Natural inseeding is also used to some extent to establish broadleaves on moist sites. Continuous cover forestry is used in special circumstances, for example recreation areas close to urban areas. Holmen aims at achieving dense and uniform regrowth,

with goals higher than what is legally required. This is the foundation of industrial and sustainable forestry. For the few areas with less than satisfactory results, the Swedish Forestry Act sets the standard for when filling in becomes necessary.

Operational planning for regeneration Planning is instrumental to success in regeneration. A number of treatments, measures and routines need to interact for a satisfactory result. Planning and high quality seeds and seedlings are prerequisites for success. Operational planning is required for site adaptation, down to micro-site level. The main site parameters are:

Parameter

Affects

– Abundance of natural regeneration (conifers)

regeneration method, shelterwood or seed trees

– Proneness to frost damage

expected seedling survival without shelterwood

– Soil type

choice of species and regeneration method

– Soil depth

choice of species

– General inclination

scarification

– Competition

choice of species

– Soil moisture

choice of species, scarification and regeneration method

– Soil type

scarification and regeneration method

– Vegetation


– Hydrology

choice of species

– Pine weevil abundance

seedling type and pine weevil protection

– Conditions for scarification

choice of scarification method

– Soil texture


– Wind exposure

feasibility of shelterwood and seed trees

Site delineation – Size of site must be big enough to justify separate treatment. – A site is an area with not too much variation in conditions for productivity. – Soil types often separate sites from each other. – Soil moisture classification on terra firme, and forest condition influence delineation. – Site boundaries often follow elevation curves. Site-tailored management prescriptions: – Harvesting method – Preparatory cutting – Residue extraction – Stump harvesting – Nature conservation and preservation of cultural heritage – Regeneration method – Choice of species – Seedling type – Number of seedlings – Pine weevil control – Scarification method – Mode of scarification – Ditching, ditch clearing – Prescribed burning Choice of species Holmen only actively regenerates species suitable for largescale forestry and for industrial use. Local conditions determine the choice of species. For areas with heavy sprouting of aspen (thus a high risk for melampsora rust) or high risk of browsing moose, spruce and lodgepole pine are preferable, provided of course that the site is generally suitable. Pine and spruce are best suited for mesic sites of average productivity, and with ground vegetation with mosses or blueberries. Pine is generally preferred on average sites for the interior of the Örnsköldsvik region (the northernmost region). There is recent scientific evidence that pine is generally superior to spruce on such sites. Spruce. Spruce is more dependent than pine on good access to nutrients and water. Spruce is considered superior to pine on sites with harsh climate as well as on highly productive sites. Pine. Pine is preferable for mesic and dry sites, where vegetation is dominated by lichens, crowberry, calluna, blueberry or lingonberry. Lodgepole pine. Lodgepole pine is used primarily on productive pine sites of blueberry type to make the best use of its growth potential. Lodgepole pine is however also an option to be considered for poorer sites. Soil texture should be coarse. Lodgepole pine is more tolerant to early summer frost than pine, but more sensitive to wind and therefore unsuitable for elevated sites, exposed sites, fine soils and watersheds. In areas of special importance with reindeer husbandry lodgepole

Lodgepole pines typically respond well to direct seeding with rapid initial growth, sound stems and thin branches. Tönningsten, Härjedalen.

pine can only be used after special agreement with the Sami communities concerned. Lodgepole pine may be planted no closer than 1 000 metres from protected areas. Conservation aspects should be given special attention when regenerating with lodgepole pine. Lodgepole pine should be regenerated through direct seeding, provided that the site is suitable for that method. Direct seeding allows for flexibility on future end use and makes thinning easier through reduced risk of wind damage. Holmen aims to have lodgepole pine on 10–20% of its total forest area. Birch. Established by inseeding in wet hollows and other moist or wet sites, dominated by sphagnum and haircap.

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In-seeding

small area?

Planting 38

No forestry activities

Wet sites?


Species selection, decision data Elevated sites in the Sveg, Ström and Stöttingen areas?

= Yes

Richer sites?

= No

Spruce Pine

Heavy grazing by moose?

Fine soils with herbs?

High incidence of aspen?


Competition from grass and herbs likely to be of concern?

Fine soils?

Spruce Lodgepole pine Spruce Lodgepole pine

Regeneration method, decision data

Dry sites?

Pine or Lodgepole pine Blueberry-type soil at best?

Planting or direct seeding

Rich in natural regeneration of pine or spruce?

Natural regeneration under shelterwood or seed trees

Frost-prone sites or sites with other special considerations?

Natural regeneration under shelterwood or seed trees

Site conditions permitting shelterwood or seed trees?

Natural regeneration under shelterwood or seed trees supplemented by planting

Dry sites?

Mesic sites?

Pine or Lodgepole pine

Planting

T-sum higher than 1000 centigrade?

Average texture?

Average texture?

Scarification method, decision data

that success is about achieving productive stands that are in tune with Holmen Skog’s environmental goals, not about cutting regeneration = Yes = No costs.

General ground inclination in excess of 15%?

Spot treatment or intermediate methods

Dry and mesic sites?

T-sum higher than 1000 centigrade?

Peat soils or more than 10 cm depth of organic material?

Remember

No scarification

Peaty soils?

Planting or direct seeding

Blueberry or lingonberry type soil?

Water hollow, small area?

Spot treatment or intermediate methods, possible continuous routing

In-seeding Planting, shelterwood or seed trees

Thin-leaved grasses or no field layer?

Brown soils or wet hollows?

Lichen types in areas with reindeer husbandry?

Blueberry-type soil at best?

Planting Moist sites?

Local site conditions largely dictate species selection and regeneration method. Climate and hydrology are particularly important. This is the best way to make use of site productivity.

Prescribed burning and direct seeding


Wet sites?

Planting, direct seeding, occasionally seed trees

Crowberry or calluna-type soil?

Spruce Pine

Species selection and regeneration method

Blueberry or lingonberry type?

Planting

Spruce Richer sites?

= No

Exposed to wind?

Lodgepole pine Pine or Lodgepole pine

Moist sites?

= Yes

Spruce

Shallow soils (less than 20 cm)?

Mesic sites?


Shelterwood

Planting

Water hollow, small area?

In-seeding Planting No forestry activities

Wet sites?

Species selection, decision data Elevated sites in the Sveg, Ström and Stöttingen areas?

= Yes

Richer sites?

= No

Spruce Pine

Spot treatment

Heavy grazing by moose?


Continuous or intermediate treatments, possibly spot

High incidence of aspen?


Spruce Lodgepole pine Spruce

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The pine weevil problem

Scarification method, decision data

= Yes

= No

Brown soils or wet hollows?

No scarification

General ground inclination in excess of 15%?


Lichen types in areas with reindeer husbandry?

Spot treatment or intermediate methods, possible continuous routing

Peaty soils?

Spot treatment

Dry and mesic sites?

Continuous or intermediate treatments, possibly spot treatment

Moist sites?


Wet sites?


What type of scarification Appropriate scarification, well executed, is of fundamental importance for success in forest regeneration. Survival rates can be improved and initial growth rates increased. Future growth and yield as well as conservation need careful consideration when selecting the method. Where applicable, reindeer herding also needs to be considered. Stones, rocks, stumps and residual logs all limit the scope of success in scarification. Sites with a harsh climate call for more radical soil treatment.

Pine weevil damage is cause for serious concern in Sweden. Planting without some form of pine weevil control is more or less futile in southern Sweden. In the north of the country, inland areas are less affected. Even in northern Sweden, however, seedlings on burnt ground – or ground that has not been scarified – are attacked. Seedling survival is, of course, fundamental to organised forestry. Direct seeding is therefore preferred on burned sites Holmen invests much time and capital in its regeneration efforts. If seedlings are not protected from pine weevil predation, these investments are in vain. At present, insecticides are used. Holmen goes to great efforts to minimise adverse effects of the chemicals used through control of dosage and properly trained staff. Holmen intends to stop using chemicals as soon as alternatives that are biologically, economically and technically feasible are available. General – Training and follow up routines should be used to maintain high quality in planting and scarification. – Direct seeding of pine and lodgepole pine is encouraged.

– Mechanical protection is further to be used on sites where scarification has created fewer planting spots than needed (less than 1 500 spots per hectare with bare mineral soil). The Iggesund region – Starpot 90 seedling pots for both pine and spruce. The Sveg district should use Starpot 50 and Uppland Starpot 120. – Mechanical seedling protection to be used on all seedlings in the Uppland, Hudiksvall, Bollnäs and Delsbo districts once they are generally available. – Mechanical protection is further to be used on sites where scarification has created fewer planting spots than needed (less than 1 500 spots per hectare with bare mineral soil). The Norrköping region – Use Starpot 120 for pine and spruce. – Mechanical seedling protection for all seedlings once such protection is available. – Retain sheltertrees wherever possible.

The Örnsköldsvik region – Use Starpot 50 for planting. – Mechanical protection is to be used for dry pine sites situated less than 100 km from the coast, once they have become generally available.

Spot treatment Crane-mounted scarifiers, mounding or screefing, through digging or routing. The scarifier may be mounted on an excavator or harvester. Intermediate treatment Scarifiers mounted on forwarders. They scarify by mounding or screefing, using modern mounders, disc trenchers or routers. Continuous treatment Scarifiers mounted on forwarders that create furrows (disc trenching or routing).

The pine weevil is a major hazard for newly planted seedlings. Illustrated here are some examples of protection. From the left a barrier, coating (glue and sand) and coating (wax).

Guidelines for pine weevil control Holmen will use mechanical seedling protection as soon as it is available for large-scale use. To be used, it must offer full protection, sound ergonomics and acceptable environmental impact at a reasonable cost. Chemical protection is used as an interim solution in agreement with the FSC®. Substances used should be accepted by the Swedish Chemicals Agency. Regulations should be strictly observed and staff involved should receive adequate training.

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Protective ditches need not be dug deep to fulfil their purpose. Miriam Nordh and Lars-Göran Nyström, Solberg, Västernorrland.

Sedimentation pit in a flat area meaning that water trickles slowly. Kolmården, Östergötland.

Ditching Ditching improves seedling establishment and enhances growth and yield. Ditching programmes have in the past reduced wetlands and swamp forests, undeniably having an adverse effect on biodiversity in wet environments. It is therefore important that drainage and protective ditching are conducted in a manner consistent with the protection of biologically valuable environments downstream. Downstream sedimentation should be avoided. Drainage is a sustainable means of enhancing a forest area’s productivity by lowering the groundwater level. Drainage requires permission from the County Administrative Board. Dense undergrowth obscures visibility and complicates harvesting and extraction of tops and branches. Illustrated here is a stand where preparatory cutting is justified. Hedvigsfors, Hälsingland.

Preparatory cutting and site clearing Preparatory cutting and site clearing facilitate harvesting and reegeneration. Harvesting becomes more cost efficient and the work environment for machine operators is improved. Competition from suppressed trees in regeneration work is reduced. If such trees are abundant, scarification becomes more difficult. Both treatments facilitate harvesting of wood residues by reducing stones and dirt in the residues. Preparatory cutting and site clearing should not be carried out on frost prone areas. If overdone, preparatory cutting can cause problems when regenerating spruce. It is also sometimes questionable from a conservation perspective. It can make buffer zone establishment difficult. It can have a negative impact on wildlife that favours dense undergrowth, such as the capercaillie. Preserving old trees that have a history of slow growth creates a variable environment where species that might otherwise perish can thrive. If there is a risk of root rot on the site, bigger trees should be left to the harvester for cutting and stump treatment.

Guidelines

for preparatory cutting and site clearing Trees obscuring vision for machine operators should be removed. Clear areas to be regenerated with pine or lodgepole pine and where there is an abundance of competition at knee height or higher. Clear areas where undergrowth is so dense that scarification results are in jeopardy.

Clear areas where hauling of forest residues is planned. No clearing or cutting only for the sake of it.

Do not clear: areas to be regenerated with spruce and where no use is made of tree tops and branches. areas to be preserved, for example buffer zones. frost prone areas.

Protective ditching regulates water levels during regeneration and the early stages of stand development. Once the new stand is established, natural drainage will start functioning again and the ditches will have served their purpose. Ditches should be dug shallow so as not to disturb shallow groundwater. Protective ditching may only be used to stop water levels from rising after harvesting. It should be reported to the Swedish Forest Agency. Ditch clearing is often required to maintain productivity levels in previously ditched areas. Ditch clearing should be reported to the Swedish Forest Agency if it affects larger areas and/or when it can be assumed to have an environmental impact.

Water quality Ditching increases the leaching of nitrogen, humus and mineral nutrients. This can be countered by a few minor yet effective measures, especially necessary in connection with watercourses of high conservation value, for example those with trout or freshwater pearl mussels. The following are some examples of what can be done. –

Sedimentation pits. Small depressions or pits to accumulate sediment. These pits should be 1–1.5 metres lower than the bottom of the ditch and dug where the water flows particularly slowly. If several pits are dug in series, they need not be so big.

–

Free flow, meaning that water is let loose before reaching bog or low lying areas. Can be combined with sedimentation pits and the flow can be distributed over wide areas. The bogs in question must have an incline to let through the water. Passage through bogs cleans water.

–

Control of water sedimentation. Ditches should not reach closer than 10 metres to lakes or watercourses so that sediments are disposed of in the terrain rather than in the water.

Guidelines for ditching Protective ditching is done to secure dependable regeneration results. Protective ditches should be shallow so as not to affect groundwater levels or long-term site productivity. Ditch clearing should, when called for, be done in connection to regeneration work and repeated once more during a rotation, for example when thinning. Ditch clearing should be done to the original depth. No ditch clearing on peat soils of low productivity.

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s k o g lRi egg p el n ae n r ea r tio ng n

For scarification, a high professional standard, and future seedling survival, means that operators follow up their work while it is in progress. Equipment must be regularly adjusted. Magnus Mårtensson of Skog och Maskin, Långviksmon, Västernorrland.

Scarification Scarification increases ground temperature and reduces the risk of frost damage. Scarification also contributes to a better water/oxygen balance. If well executed, scarification also releases nutrients and disturbs capillary water movements in the soil, reducing the risk of frost heaving. Scarification reduces competition from grass, herbs and shrubs. It enhances seedling vitality and the ability to cope with stress. It further reduces exposure to pine weevil attack. The type of scarification selected should be consistent with the regeneration method chosen and carried out as soon as possible after harvesting. In areas where reindeer husbandry is practised, and where

the ground is rich in various types of lichen or scrub with scattered lichen, gentle scarification methods should be used, meaning methods that do not negatively affect availability of lichen, unless otherwise agreed. Scarification and planting To be worthwhile from a regeneration point of view, scarification must be done to a high standard. Holmen typically plants 2 100 –2 500 seedlings per hectare depending on site productivity. The number of planting spots created is of obvious importance, as is the nature of these pots. If scarification is to be of use as a protection against pine

Guidelines for scarification Scarification should be carried out as soon as possible after clear felling so as to make the regeneration phase as short as possible. Equipment should be adjusted to fit local site conditions and their within-site changes. Make sure that the ground pressure applied helps achieve the desired results. No scarification of local wet areas often dominated by sphagnum mosses. Do not scarify areas with brown soils. Spot or intermediate treatment should be preferred on slopes with a general inclination of at least 15%. Intermediate methods are to be used on wet sites and degenerated heathlands. Mesic sites dominated by lichen or calluna should be treated by mounding. Mounding using an excavator should be used on sites with hard pans. Methods minimising impact on lichen should be used on lichen-dominated sites in areas where forestry co-exists with reindeer husbandry. For work safety reasons, care should be taken around remnant trees. Areas with conservation measures prescribed should be avoided, as should larger stumps and dead wood. Check for archaeological remains before the operation. These may under no circumstances be damaged. As a rule they are demarcated in the field. Walking paths should be left alone.

Trenching is the most common scarification method, Norsjö, Västerbotten.

weevil damage, planting should be done in mineral soil, at least 10 centimetres from the humus. When mounding, mineral soil should cover the underlying humus. The mound should always be in contact with the ground. Scarification should be site-adapted to secure the best possible result in terms of number of good planting spots. Maintenance and adjustment routines for the equipment as work progresses are a must, particularly on sites with varying ground conditions. Operators need to be active and observant in their work. Special attention is needed when scarifying sites which have not been subject to harvesting of forest residues, as branches and tops may prevent creation of planting spots and/or soil contact. Optimal scarification spot – Mineral soil on a mound where the seedling can be planted at least 10 centimetres from the nearest humus. Acceptable scarification spot – Bleached soil on dry and mesic sites with the seedling at least 10 centimetres from the nearest humus.

germination, seedling establishment and reduce frost heaving. If done too deep, the risk of frost heaving increases. Optimal seed bed – Mineral oil with a mixture of humus. Acceptable seed bed – Leached horizon. Seed beds to be avoided – For example undisturbed humus. Scarification and seed trees The effects of scarification under seed trees need to be more long-lasting, as regeneration takes longer. More radical treatment is required than for direct seeding to ensure that mineral soil is exposed enough. Seed trees need time to respond to release after harvesting. Ample seed fall can be expected after three growing seasons. Scarification should therefore be carried out in the autumn, after three growing seasons. Optimal seed bed – Leached horizon.

– Mound on moist sites, fine soils and peat sites with little or no mineral soil.

Acceptable seed bed – Mineral soil mixed with humus.

Scarification and direct seeding Scarification should strive to reach the layer between humus and mineral soil, the leached horizon. This is to enhance seed

Seed beds to be avoided – Undisturbed humus and elluvial soil.

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Field handling of seedlings It is important that seedlings are handled with care while in storage; health, vigour and nutritional status are maintained until they are planted. Seedlings delivered in frames need to be watered several times per day in dry and warm weather. Seedlings are not to be stored outdoors for more than ten days. Seedlings stored in cardboard boxes are hardier but guidelines (see box) need to be strictly observed to control mould fungi and other hazards. Optimal planting spot Regeneration results depend on planting being carried out well. Best possible use should be made of scarification, even on sites where the scarification could have been better. Great care should be taken when working around snags and trees to be preserved. They are safety hazards. Optimal planting spots (see below) are always the first choice. Lacking optimal spots, planters should opt for good spots. As the name implies, such spots are acceptable, although not optimal. Lacking even that, the planter is trusted to make the best out of the situation. To prevent pine weevil damage seedlings need to be at least 10 centimetres away from the nearest humus. Planters should make sure that mounds have good contact with the soil. If they do not, there is a high risk of seedlings drying up and dying. This is particularly critical when planting is done soon after scarification with no winter between. Seedlings should be planted deep in the ground on elevated spots. To avoid frost heaving, seedlings should not be planted in spots with elluvial soils. Elevated spots are particularly important in the interior north where climate is a particularly limiting factor for seedling growth.

Seedlings dry up fast when the weather is sunny and dry. Regular watering is needed. This is how wet a seedling should be. Björna, Västernorrland.

Planting Planting using genetically improved seedlings is the dominant regeneration method at Holmen. It is a robust method adequate for most site conditions encountered in Holmen’s forests. Good planting means that a high future production is to be expected Planting beneath shelterwood is a good alternative for frost prone areas. Planting spruce under a shelterwood of pine is well worth considering in southern Sweden, with a possible seed fall as a potential bonus. Reduced competition from surrounding vegetation and reduced pine weevil damage are other benefits from the method. Finally, the method is a robust way of establishing mixed forests. Planting should be carried out as soon as possible after scarification to shorten the regeneration period. Pine weevil damage must be taken into consideration in this process. Planting is typically done in spring and early summer. From

Seedling size

Pot volume, cm3

a nursery point of view it would be desirable to increase the share of planting done in autumn. Seedling size Holmen seedlings come in three sizes: For normal sites in the Örnsköldsvik region and the Sveg district S50 seedlings are the main alternative. For the Iggesund region, except the Sveg and Uppland districts, S90 is the main alternative for both pine and spruce. The biggest seedlings, S120, are normally used in the Norrköping region and Uppland district. Bigger seedlings should be used for filling in and for sites with a high risk of frost heaving, summer frost, competition from surrounding vegetation, pine weevil damage or browsing by roe deer. Survival rates are typically higher for larger seedlings. They also tend to have higher growth as young trees.

Spacing, seedlings/m2

Diameter of main root, mm

S 50

50

730

about 2

S 90

90

440

about 3

S 120

120

308

about 4

Optimal planting spot – Mineral soil on a mound where the seedling is at least 10 centimetres from the nearest humus. The mound should have proper contact with ground. Good planting spot – Patches of leached horizon on dry and mesic sites, with the seedling no closer than 10 centimetres to the nearest humus. – Mounds on moist sites, fine soils and peat soils with little or no mineral soil. In the Örnsköldsvik region this applies to sites more than 100 kilometres from the coast, or if the seedlings have pine weevil protection. Mounds should be in contact with the ground. Other planting spots, descending priority – Mounds failing to meet the specified standard. – Elluvial soil (dry and mesic sites). – Spots with humus. – Spots with mineral soil on moist sites and fine texture soils. – Unscarified spots. – Mounds with poor ground contact.

An optimal planting spot provides the seedling with: Pine weevil protection. Low risk of frost heaving. High ground temperatures. Limited competition from surrounding vegetation. Nutrients in ample supply. Sound balance between water and oxygen supplies.

Guidelines for seedling storage General Nurseries deliver dormant seedlings from cold storage throughout spring. For other parts of the year, growing seedlings will be delivered. Seedlings in growth require special care in transit and in handling. Seedlings should be planted in the order they arrive – first come first planted. Field storage should be under shade, and not prone to frost. Watering should be facilitated, and cloths to provide shade should be provided. Moisture of seedlings should be checked first thing on arrival. It should be possible to squeeze water out of the substrate. Seedlings treated with insecticides should be kept well away from watercourses. This applies also to cardboard boxes and cases that have been used for seedling storage. Seedlings delivered in frames Minimise storage time so that vigour is preserved. Field storage should not exceed ten days. Seedlings delivered in cardboard boxes Always remove the plastic cover of the boxes on delivery.

If boxes need to be stored in coolers during delivery, boxes need to be closed until arrival on the planting site. Seedlings in cardboard boxes should not be kept in coolers for more than a week after thawing.

Seedlings delivered in September and October should not be kept in their boxes for more than 2–3 days. Push the perforated spots to create holes in the box immediately after transport to the planting site. Sample seedling moisture and water as needed. Empty boxes should be taken care of. Littering is not permitted!

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Seedlings need to be taken care of all the way from the nursery until they are planted. Drought should be avoided. Yvonne Hedman, officer in charge of seedling production.

Recommended spacing and number of seedlings per hectare for coniferous seedlings Average distance Scarifica tion – tracks

Site index

Row spacing, metres

2.0

–SI 18

SI 20–22

SI 24–28

SI 30 +

2 300

2 500

2 700

2.4

2.2

2.0

1.9

2.2

2.2

2.0

1.8

1.7

2.5

1.9

1.7

1.6

1.5

3.0

1.6

1.5

1.3

1.2

Seedling density desired 2 100

Planting is manual work. A large part of the labour force comes from Eastern Europe. Björna, Västernorrland.

Guidelines for planting

Extended periods of drought are unsuitable for planting as is late summer with its low groundwater levels. Exercise caution when working close to retained trees, they might fall and cause serious bodily harm. Make sure that seedlings are healthy and well watered before planting. It should be possible to squeeze water from the peat substrate surrounding the roots. Do not bother to plant dried up or otherwise damaged seedlings. Handle seedlings with care, for example do not tear them out of their cases. Seek optimal planting spots first and good ones second. Try to plant the seedling at least 10 centimetres from the nearest humus to reduce the risk of insect predation. Seedlings should be planted deep into the soil, especially when planting in mounds of mineral soil. About half of the green part of the seedling should end up beneath the soil surface. This does not apply for moist sites and particularly short seedlings, nor for seedlings protected against pine weevil. Compact the soil surrounding the seedling when planting in humus or spots of leached horizon. This also applies when planting soon after harvesting and for bare rooted seedlings. Seedlings should be spaced at least 0.6 metres apart. During extended dry spells, planting on bleached soil patches is preferred, provided that the soil is not rich in fine particles. On unscarified sites, spruce should be planted at the north end of stumps, fallen logs and rocks, while pine should be planted to the south. On sites with a harsh climate, all trees should be planted at the southern end. To reduce frost heaving, avoid planting in elluvial soil and spots with leached horizons on fine soils.

To survive and grow well, seedlings must be well managed, handled with care and properly planted at suitable spots. Here is an example of an optimal planting spot in Älvros, Härjedalen.

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Germlings thrive in mixtures of mineral soil and humus. Seedlings in elluvial soils are prone to frost heaving.

Direct seeding induces competition at an early stage and thus increases scope for a high quality crop.

Direct seeding

– Avoid soils with coarse texture. – Avoid sites covered by 10 centimetres of organic material or more. – Sites with a general inclination of 15% or steeper should be scarified using direct or intermediate methods.

For some sites, direct seeding is the preferred regeneration method. When well executed, direct seeding can result in dense stands with well-developed root systems. Direct seeding is a more demanding method than planting and has a more limited scope of use. The method is cheaper, but some three years are lost compared to planting. When used in southern Sweden the method should be applied with caution, and limited to poorer sites. Micro-site preparation ensures more dependable results. Seedlings established through direct seeding take some time to establish themselves and reach sizes attractive to pine weevils. Most pine weevils will actually have left the site in search for pastures new before they do. This means that seeded seedlings have more resin and thus capability of defending themselves compared to planted seedlings. Direct seeding also results in a high number of seedlings, and this in itself increases the likelihood of a sufficient number of seedlings that have ‘evaded’ the weevil. Holmen investigations indicate that three years are lost through direct seeding compared to planting. After pre-commercial thinning, stands established through direct seeding are denser, somehow compensating for the years lost. Direct seeding is the main method used for lodgepole pine, and it is the ambition to greatly increase its use for pine. Seeds depend on capillary water for their germination. Direct seeding should therefore be avoided in July when groundwater levels tend to be low. July is also a month when bird predation of seed is high. Sites suitable for direct seeding – Direct seeding is suitable for sites dominated by blueberry or poorer. – Priority should be on mesic and medium coarse tilly soils.

Dense regrowth of lodgepole pine secured through direct seeding. Direct seeding results in trees with straight stems, well developed root systems and thin branches. Bror Österman and Olov Norgren, Rönnäs, Västerbotten.

Guidelines for direct seeding

Seeds and seed handling

Direct seeding in northern Sweden should be carried out from mid-May to late June. Direct seeding can be used in autumn for lodgepole pine.

Seed origin for pine should be 75% wild seed and 25% orchard seeds. This ensures that a sufficient number of seeds can be dispersed and that orchard seeds are evenly distributed over the area. Stem selection can be done at precommercial thinning. Lodgepole pine, for which direct seeding is feasible even in autumn, needs a cold and wet period to break seed dormancy and start germination. Seeds need to germinate with some urgency when direct seeding is done during spring. A so-called cold/wet treatment is done to ensure that. This is done by Holmen’s Seeds and Seedlings Unit. Dormancy should not be broken when direct seeding is done in autumn. Should germination commence, seeds risk freezing damage.

Direct seeding can commence in April in southern Sweden. Early summer, with its dry spells, should be avoided. Mechanised direct seeding under seed trees should be done in early spring to make use of natural inseeding. Manual direct seeding is done only after scarifi cation. Care should be exercised around trees retained as they may blow over. Direct seeding on sites treated with prescribed burning should be done two growth seasons after harvesting to reduce risks of damage from morel. Make sure that seeds are placed in mixtures of humus and mineral or bleached soils. Avoid elluvial topsoils or undisturbed humus. Seed density should be 10 to 15 germinable seeds per metre scarified, corresponding to 0.15 to 0.3 kilos per hectare. Shelterwoods of about 100 trees per hectare should be retained in southern Sweden.

Cold/wet treatment. To be carried out on seeds of lodgepole pine to be seeded in spring and early summer. No cold/wet treatment. Lodgepole pine seeds dispersed after August 15 should not be subject to cold/wet treatment. Districts should store surplus seeds in coolers and in closed containers so that they can be used the next year. The quality of surplus seeds cannot be guaranteed and they should therefore not be sent back to nurseries.

Guidelines

for seed handling in connection to direct seeding

Seeds should be ordered no later than November the year before direct seeding. This is needed to permit time for seed treatment. Seed delivery should be asked for at least two weeks in advance to permit time for mixture of wild and orchard seeds. Seed germinability should be at least 80%.

Seeds should be stored in cool conditions and under shade. Cooling bags in cars and forest machinery should be used. Seeds should not be subjected to mechanical stress or high temperatures.

Surplus seeds should be stored by districts in cool conditions and in closed containers (for example clean and dry plastic containers). The seeds can be used the following season. Seeds should not be subject to freezing. Seeds should not be stored for more than two years. Make sure that containers have adequate documentation.

Lodgepole pine seeds should be given cold/wet treatment before spring-early summer dispersal. No cold/wet treatment should be performed on seeds to be dispersed after mid-August.

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Moist peat lands with favourable climate can be regenerated by shelterwood. Finspång, Östergötland.

Regeneration with seed trees is a method that should be used sparingly, results are usually inferior to direct seeding and planting. Länna, Uppland.

Spruce shelterwood

Seed trees

Forests on moist and peaty sites with a favourable climate can be regenerated using shelterwood. Existing natural regeneration – either freshly germinated seedlings or the type found in storm gaps – indicates the scope for success. Shelterwood reduces problems caused by frost, water stress and competition from vegetation. Shelterwoods are prone to damage by wind. The method requires highly qualified staff, and offers plenty of opportunities for error. The use of shelterwood involves long-term losses in growth and yield, and is not widely practised in Holmen’s forests. Suitable stands: – A favourable local climate with a temperature sum of at least 1 000 day-degrees or where natural regeneration of conifers is already abundant. – North-western slopes are to be avoided. – Shelterwoods should be included in operational planning well prior to establishment, to preclude proximity to large clear felled areas. – Dense stands are unsuitable for shelterwood. – Careful consideration should be paid to the risk of wind damage. Suitable sites: – Sites with an abundance of natural regeneration prior to harvesting. – Moist sites. – Peat soils or terra firme with a layer of organic material thicker than ten centimetres.

– Preferable vegetation is thin-leaved grasses or sedge, as well as blueberry and lingonberry scrub. Alter natively, ground with no field layer.

Guidelines

for regeneration using shelterwood of spruce Shelterwood may be selected from all tree layers and should be varieties that are able to withstand storms. Shelterwood density should be about 250 trees per hectare. The richer the site, the denser the shelterwood. The harsher the climate, the sparser the shelterwood. There is no need for uniform density on a site. Where natural regeneration is abundant, shelter wood can be sparser. Where conditions or sites differ from those described above, the ground beneath the shelter wood should be scarified and planted or seeded, if in situ regeneration is too sparse. Ditches should be cleared to enhance shelterwood vigour. Shelterwood should be retained until seedlings are tall enough to escape frost damage. Where frost is not a problem, the shelterwood can be removed when seedlings have grown to a height of between 0.1 and 0.5 metres.

Given sites with a favourable climate and a good number of ‘storm-proof’ trees, seed trees can be a way to regenerate stands. The method is still unpredictable, however, and should be applied with extreme caution and only in limited areas. In southern Sweden, the method is restricted to poorer sites. Compared to planting and direct seeding, the seed-tree method results in significantly lower forest production. Suitable sites: – Mesic types on intermediate sediments. – Preferred vegetation: sedge, blueberry or lingonberry. – The temperature sum should exceed 1 000 day-degrees where there is a lack of natural regeneration prior to harvesting. Natural regeneration under seed trees can also succeed on sites with a harsh climate. Check whether freshly germinated seedlings are plentiful or not. Risk of wind damage is a primary concern.

Natural inseeding

Guidelines

for natural regeneration using seed trees ‘Storm-proof’ trees with large and symmetrical crowns should be evenly distributed over the area (see table below).

Recommended spacing for trees

Spacing, metres

Seed trees per hectare

T 24 +

8

150

T 20 –T 22

10

100

– T 18

11

80

Scarification should be carried out during the autumn of the third growing season after harvesting. On frost-prone sites, seed trees should be retained until seedlings are safe from frost damage. If natural regeneration has been found scarce, scarify and plant beneath the seed trees on all sites except those described to the left. If frost is not a problem, the seed trees can be re moved when seedlings have grown to 0.1–0.5 metres.

Natural seeding normally refers to the natural establishment of birch or aspen stands through inseeding from the surrounding forest. The method should be sparsely used. A main motive for the method is Holmen’s ambition to ensure that 5% of its forests should be dominated by broadleaved species.

– The regeneration site should be no further than 100 metres from the seed source.

Suitable sites: – Natural seeding is appropriate for wet hollows and in pockets where sphagnum and haircap mosses predominate. – Natural seeding is inappropriate for frost-prone sites.

Stand establishment: – Some four to five birches per hectare (preferably silver birch) should be retained. – Preparatory cutting and scarification should be avoided.

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Monitoring and evaluation of scarification and planting A high professional standard of scarification and planting is fundamental to the success of regeneration and to securing future stands that offer high growth and yield. It is therefore important that contractors, districts and regions monitor and evaluate this process and continue to refine the methods used. Scarification and planting are monitored and evaluated to: – Sustain ongoing adjustments to secure the right number of optimal and appropriate scarification and planting spots. – Confirm adherence to plans and standards. – Keep the stand catalogue up to date and, where applicable, update forest management plans for other forest owners. – Ensure that current nature conservation and forestry guidelines are observed.

Make sure that water quality is not jeopardised when ditching. An example of free flow from Norsjö, Västerbotten.

Conservation measures taken need to be respected. Traces of Tragosoma depsarium on a dry lying log. Do not damage dead and dried up trees and retained lying stems when scarifying. Flen, Södermanland.

Guidelines

for monitoring and evaluation of scarification The machine operator ascertains that the number of scarification spots per hectare is as specified. Proper sampling is done, and recorded, twice per working shift. Serious deviations from the current guidelines are reported in writing. Scarified sites are sampled and checked to confirm compliance with the standards prescribed by the Holmen Group’s central monitoring system.

Conservation and cultural heritage Biodiversity is something considered already at the regeneration stage.

Guidelines for conservation and regeneration Non-productive land: Scarification should be avoided on non-productive land. Damage caused by timber extraction is unacceptable. Sensitive biotopes: No preparatory cutting. Regeneration work should not be carried out on particularly sensitive biotopes and surrounding protective and buffer zones.

Guidelines

for monitoring and evaluation of planting Regularly check that the number of seedlings is as specified. The performance of every planter is recorded, normally two samples per shift. Serious deviations from the current guidelines are reported in writing. Planting sites are sampled and checked to confirm compliance with the standards prescribed by the Holmen Group’s central monitoring system.

Cultural heritage: Cultural heritage sites often gain from the removal of trees. Regeneration work on achaeological sites requires special permission from regional authorities. Archaeological and cultural heritage sites are not to be damaged. Contact regional authorities when planning. Areas surrounding heritage sites often require special consideration. Abandoned heritage sites of less than 0.5 hectares should not be planted. Scarification and ditching: Protective zones should not be scarified. Fallen logs, dead standing trees, high stumps or specially preserved trees should not be damaged by machinery. Care should be taken to avoid erosion or undesired leaching when scarifying. Mineral soils should not be worked more than required for good regeneration. This is particularly important on land where reindeer husbandry is practised. Ditching should not adversely affect streams, lakes and wetlands. Chemicals: Make sure that spillage water does not reach watercourses when seedlings are stored and watered outdoors. Remember that wrapping might be contaminated by chemicals. Shelterwood and seed tree removal: Trees and high stumps selected for retention should be intact and remain in place after shelterwood or seed trees have been removed.

Sound monitoring and evaluation routines enable regular improvements. Olov Norgren and Robin Jacobsson, Solberg, Västernorrland.

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skoglig planering

skoglig planering

PreCommercial Thinning Pre-commercial thinning, sometimes called spacing, promotes a quality crop and provides retained trees with the opportunity to respond to increased space and better access to light, water and nutrients. Pre-commercial thinning is done to secure dense and vigorous forests.

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Pre-commercial thinning well executed results in dense and vigorous stands Most young stands of forest need a pre-commercial thinning some ten years after establishment, when main stems have started reaching heights of two to three metres. Regeneration has then been secured and there has normally been considerable natural inseeding, particularly of birch. Pre-commercial thinning should be so balanced that high wood production is secured as well as good economics for future thinnings. Even seemingly sparse stands need to be treated as they often have dense parts and groups of trees. If done too late, production is lost, treatment costs increase and work becomes more cumbersome. Pre-commercial thinning leads to lower costs for future thinnings. Timber production also increases as a result of pre-commercial thinning. Pre-commercial thinning aims at creating as well stocked and vigorous stands of as high quality as local site conditions permit. By regulating stem numbers, species composition and stratification, retained trees are given more space, light, water and nutrients. High quality individuals are retained and permitted to develop into valuable trees. In normal forests, pre-commercial thinning can be designed to promote the future development of natural values. The percentage of broadleaved species can be regulated. This can lead to fully stratified buffer zones, rich in broadleaves, either through pre-commercial thinning or by doing no pre-commercial thinning at all. Pre-commercial thinning may well be the single most demanding, important and interesting silvicultural treatment. Properly conducted, pre-commercial thinning balances a number of more or less contradictory goals, as suggested below. Objective Action High volume production

early treatment, dense spacing

High timber quality

late treatment, dense spacing

High average tree diameter

early treatment, wide spacing

Low treatment costs

early treatment, once only

Minimise competition from coppice

late treatment

Minimise insect predation

early treatment

Planning for success in pre-commercial thinning The stand catalogue and remote sensing are valuable tools in identifying areas in need of pre-commercial thinning. Helicopter surveys are useful in planning pre-commercial thinning. Treatment planning is done using operational planning routines. If the treatment prescription has to vary within the stand, the stand should be divided into sites. There may be a need for special conservation measures, areas needing shelter-

Lodgepole pine is a most vigorous species and stems to be removed should be cut beneath the lowest whorl. Tönningsten, Härjedalen.

Guidelines

for scheduling pre-commercial thinning It is Holmen practice to do pre-commercial thinning when main stems have reached heights of two to three metres. Kolmården, Östergötland.

wood for frost protection and species composition may need to vary within a stand. It is important that pre-commercial thinning is conducted during the proper season, to prevent cut stems from serving as breeding grounds for insects. Conifer stands with stems more than seven centimetres across should be treated during the following periods: Pine (Hälsingland and south)

15 May–15 July

Pine (Härjedalen and north)

1 June–15 July

Spruce

1 August– 30 September

Scheduling pre-commercial thinning It is Holmen policy to conduct pre-commercial thinning when main stems have grown to heights of between two and three metres. This prevents birch shoots from growing higher than the main stem, so that a single treatment per rotation will normally suffice. This applies also to sites regenerated with direct seeding where seedlings have had to compete for space when young, promoting quality. Pre-commercial thinning should offer a means to counter damage caused by browsing moose. This is an area that is little understood and thus deserves further research. If carried out when trees have reached two to three metres, stand vigour will be high, with a high needle mass, resistant to browsing animals. Tall and large trees are more difficult for moose to damage. Even when overdue, the pre-commercial thinning process remains essentially the same, though operational costs are higher and the work more time-consuming. Volume production will also be lower. Cutting the cost of future thinnings is a strong argument for pre-commercial thinning.

Pre-commercial thinning should be carried out when main stems have reached heights of between two and three metres. Low shelterwoods of broadleaves can be established when the broadleaved species have reached heights of three to four metres. Main stems of spruce will normally be much lower when that happens. If the pre-growth of broadleaves jeopardises or causes damage to the growing main stems of conifer species, pre-commercial thinning should be carried out regardless of tree height.

Species composition and prioritisation Species vary in site preference. Care should therefore be taken to ensure that species and site match each other after precommercial thinning. Holmen strives to achieve a 5% to 10% share of broadleaved species after pre-commercial thinning in coniferous stands. Mixed coniferous stands Holmen strives for mixed coniferous stands at average mesic sites, with a ground vegetation of mosses, blueberry or lingonberry. Mixed stands are resilient against root rot, insect predation and fungal attack. Pine should be permitted to dominate in mixed coniferous stands. Care should be taken that spruce retained is vigorous and of the same size as the pines. This is particularly important in the interior of the counties of Västerbotten and Västernorrland. Pine and lodgepole pine Pine is favoured on poor and dry sites with a ground vegetation of lichens, crowberry, calluna or lingonberry. Pine is a light-demanding species that establishes itself after fire or final felling. Pine requires a lot of light and does not thrive when shaded by other trees. Lodgepole pine does not differ from pine in terms of precommercial thinning. Being a most vigorous species, stems removed have to be cut below the lowest whorl. Main stems of birch should be spaced about 2.5 metres from lodgepole pines.

Prevent sprouting by leaving two or three stems in every ‘bouquet of coppices’. Para, Västernorrland.

Spruce Spruce is the preferred species on high productive and moist sites with ground vegetation dominated by mosses and blueberry with herbs and herb types on slopes. Depressions are often dominated by grasses and herbs. Sites with near saturated topsoil or shallow groundwater are often suitable for spruce. Spruce is a shade-tolerant species that typically establishes itself beneath more fast growing light-demanding species, such as birch. Smaller spruce to be removed should be cut as close to the ground as possible to avoid sprouting and problems in future thinnings. Broadleaved species should be spaced at least 2.5 metres from main stems of spruce. Broadleaves Broadleaves are preferred on moist to wet sites dominated by horsetail, haircap or sphagnum mosses. Birch is light-demanding, rapidly establishing itself on new sites. Birch is useful in filling regeneration gaps. From a conservation point of view, an increased share of broadleaves is desirable. Silver birch is the first choice among broadleaves. Coppicing can pose a problem in pre-commercial thinning of broadleaves. It can be reduced by retaining one or two stems per ‘bouquet’.

Guidlines for Species preference in pre-commercial thinning

Conifers are generally preferred. Site conditions dictate choice of species: – Pine and lodgepole pine on dry and poor sites. – Mixed stands on average mesic sites. Make sure that the share of spruce is controlled in the interior of the counties of Västernorrland and Västerbotten. – Spruce on rich and moist sites. Where conifers are missing settle for a broadleaf. The share of broadleaves depends on stand age and appearance, and on the availability of acceptable broadleaf species. Preferred broadleaf percentages are: – At least 5% in northern Sweden. – At least 10% in southern Sweden. Broadleaves found in protected zones and in areas subject to special consideration are included when assessing broadleaf percentages.

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Pines badly browsed by moose that do not compete with the nearest main stems can, and indeed should, be retained. They tend to be more in demand than undamaged stems. Skaldalen, Västernorrland.

Shelterwood of broadleaves covering spruce adds to growth and provides frost shelter. Robertsfors, Västerbotten.

Stem types and what stem to retain and what to remove Main stems A main stem is a tree that will remain part of the stand after thinning. Main stems are selected from the highest quality and most vigorous trees. Thinning stems Thinning stems compete with main stems and should be removed. It is important that spruce stems to be removed are cut below the lowest green branch. If they are not, they will keep growing, as spruce is shade tolerant, and become a nuisance in future thinnings. Individuals that have been heavily browsed, but that do not compete with main stems, can be retained in the stand. They tend to be more attractive for moose than other trees.

Equipment should be kept in good condition and blades sharp. Safety prescriptions should be observed.

Need for pre-commercial thinning – number of trees – spacing The stand density of young forests determines much of their future development. It is important that growth is allocated to trees planned for removal in later thinnings and final felling. There is no need for pre-commercial thinning in coniferous stands with less than 2 800 evenly distributed stems per hectare. The corresponding figure for stands of birch is 2 100. Pre-commercial thinning in areas regenerated through direct seeding, seed trees or shelterwood should be conducted when seedlings reach a height of two to three metres, to counter aggregation of regeneration. This also applies where regeneration through planting has been unsuccessful. On average sites Holmen aims at 2 300 main stems per hectare (corresponding to spacing of 2.1 metres) after precommercial thinning. There should be some 2 000 trees per hectare at the time of the first thinning, when trees have reached heights of 12 to 14 metres.

Spacing of birch should be 2.5 metres, or 1 600 stems per hectare, to stimulate radial growth. Main stems can be regarded as central points in circular areas corresponding to the space required for favourable development. The desired stand densities can thus be expressed as the radius of the circle required by the main stem. It is more important that the best stems are retained than to keep a precise spacing. The table below indicates the target for the maximum number of stems. On very poor sites (such as the Sveg district), somewhat wider spacing can be accepted than that indicated in the table. In very rich areas, stands can be somewhat denser. Field instructions for pre-commercial thinning are kept simple. Spacing should be uniform for a site, unless there are obvious reasons to do otherwise. When conducting precommercial thinning, it is important that spacing is regularly checked using circular plots. Maximum density – number of stems – radius Pine, lodgepole pine and spruce

Birch and aspen

SI

Stem density Radius SI (stems/ha) (m)

Stem density Radius (stems/ha) (m)

24+

2 500

2.0

24+

1 900

2.3

20–22 2 300

2.1

B20–22 1 600

2.5

–18

2.2

–B18

2.8

2 100

1 300

The number of stems stated above includes broadleaves if they are present in normal numbers. If a stand is estimated to have a share of broadleaves of more than 40% after treatment, stem numbers should be calculated based on degree of mixture and numbers desired for conifers and birch respectively.

Lodgepole pine established through direct seeding should be thinned to denser spacing, if possible as high as 3 000 per hectare (a spacing of about 1.8 metres). In the absence of conifers, silver birch is acceptable as a main stem. Local spacing required by the species should be the determining factor. If stand edges are to be denser, local density regulations can be overruled. Main stems, however, may never be closer than 1.0 metres. Fast growing broadleaved species should always be at least 1.5 metres from pines or lodgepole pines.

Broadleaved shelterwoods above spruce If a stand is clearly two-layered and broadleaves constitute the upper layer, a shelterwood should be created. Such shelterwoods increase volume production and improve the quality of spruce undergrowth. The shelterwood also protects against frost and inhibits coppicing of broadleaves. Broadleaved shelterwoods are established if suitable broadleaved trees are available, and if the area is big enough to justify reporting it as a separate stand. The shelterwood is created by pre-commercial thinning when the broadleaved trees are three to four metres high. Broadleaves with elevated crowns are favoured, to avoid mechanical damage to the spruce. Shelterwood density is varied according to the table above and, of course, in response to local conditions. For areas highly prone to frost, shelterwood densities of 1 900 stems per hectare may be necessary. Using broadleaved shelterwoods means lower numbers of spruce can be accepted. Shelterwoods are removed when the trees forming them are big enough for thinning. Thinning shelterwood trees is often difficult as damage to the spruce undergrowth must be avoided and conditions may vary considerably between, and indeed within, sites. A rule of thumb is, if sight conditions

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Recent pre-commercial thinning on a previously burnt area that has been regenerated by means of direct seeding. Gäddvattnet, Västernorrland.

Broadleaves are favoured and preserved around watercourses. Fiskån, Jämtland.

permit, thin the spruce undergrowth to the spacing desired sometime after the shelterwood has been removed. Logging debris will have fallen to the ground, and the choice of what stems to retain and remove is made easier.

Pre-commercial thinning and conservation Pre-commercial thinning increases biodiversity of field layer avian fauna and flora. The most common conservation measure in connection with pre-commercial thinning is exemption. Active creation of biotopes is rarely implemented prior to thinning, at which time it generates income from timber harvested. Should there be reasons for active creation of biotopes, creation of layered areas of broadleaves is often worth considering. Potential conservation trees should be favoured. In conifer stands, these are normally sallow, mountain ash, rowan, linden, maple and wild cherry, as well as large juniper trees and hazel. Trees impeding the development of conservation trees should be removed. Conifers are favoured where the above species are abundant (if the stand hasn’t been earmarked for special management in the conservation plan). Potential conservation trees are selected in protected zones or wherever they occur in groups, to create and promote variation. High stumps are liberated so that they are exposed to

sunlight, favouring wood-living insects. Work in connection with high stumps, snags and conservation trees is potentially dangerous and should be done with care, especially in windy conditions. Pre-commercial thinning is not done on unproductive land. Such areas have a unique flora and fauna. Senescent, slow growing and dry trees are more abundant than on productive land. Pre-commercial thinning in environments that require special care, such as wet hollows, wells and small streams, should strive to ensure long-term preservation and natural development of these environments. Stratified small broadleaved stands should be preserved and the development of particularly large trees should be favoured. All trees competing with large oaks should be removed. At archaeological and cultural heritage sites, care should be taken to ensure that tree roots cause no damage. Debris should not be allowed to obscure the sites. Pre-commercial thinning is not done on sites with a history of charcoal production. Regional authorities should be consulted regularly to avoid mishaps.

Monitoring and evaluation of pre-commercial thinning Pre-commercial thinning has a major impact on the future development of a forest, and the value of the entire Holmen

forest estate. Correctly carried out, pre-commercial thinning ensures valuable stands at the time of thinning and high yields of saw timber at later stages of the rotation. It is therefore essential that the work is properly monitored at every level and each stage. Monitoring and evaluation also provide feedback for improved methods and routines. Monitoring and evaluation of pre-commercial thinning aims to: – Ensure that specified spacing and species mixes are achieved. – Check adherence to the directives given. – Report to the stand catalogue or to the management plans for private forest owners. – Ensure that guidelines for conservation and forest management are followed.

Guidelines for monitoring and

evaluation of pre-commercial thinning Field staff check regularly to confirm implementation of desired spacing and species mix. Monitoring of fieldwork to be carried out on two documented spots every shift. At least five field checks to be carried out, regardless of the size of the area treated. Failure to observe instructions should be reported. Areas treated should be sampled and studied as per routines specified by Holmen.

Pre-commercial thinning is a treatment that greatly influences the appearance and development of the future stand. Mats Norr, Ljusdal.

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Thinning Thinning is a treatment of great importance for the development of the area treated. Trees retained will have more space and better access to water and nutrients. Quality is enhanced. Damaged and otherwise defective stems that would perish naturally are removed and made use of. If well executed, thinning yields both profit and valuable wood production.

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Thinning

Thinning

natural values and lies at the heart of efficient conservation when the time has come for final felling. Planning is required to minimise damage from hauling to the degree possible. Selection of areas to be thinned – Use the Holmen support functions and tools available for planning. Preliminary selection may require a follow-up audit in the form of a field check or helicopter survey.

After a second thinning the forest is left to grow until final felling. Now it starts to look like something. Markus Edvinsson, Skorped, Västernorrland.

Thinning should benefit trees of high quality, thereby raising future timber values. Thinnings also contribute 26% of the annual wood harvest on Holmen forest land, which makes a vital economic contribution to Holmen Skog. Thinning, pre-commercial and commercial, is about reducing the number of stems per hectare in the forest so that production is allocated to valuable stems. There is also an effect in terms of growth rate in selecting the best trees for retention. Thinning from below with a focus on quality means that a relatively high number of slender stems of low quality are removed, and the best retained. Site adaptation, selection of trees to remove/retain thinning rate and damage control are the keys to success in thinning. Keeping these factors in mind while thinning raises the value of the Holmen forest estate. Thinning is typically done in middle-aged stands that lack trees from previous tree generations. Conservation therefore has to be active rather than preservative. Concentrating conservation efforts also makes future conservation work so much easier. Thinning stands will become a more and more prominent feature in tomorrow’s forest landscape, they will become more common than old stands. It is now our responsibility to create structures and environments that favour diverse flora and fauna, so-called future biotopes. Diversity already found can be reinforced by for example retention of large pines or broadleaves or creation of high stumps. Conditions for diverse flora and fauna can be improved in tomor-

row’s thinning forests simply by being creative, and wood production need not suffer.

Planning for success in thinning Timing is important. Young stands not yet thinned are at their highest growth rate, and will respond rapidly to new conditions created by thinning. Proper timing is important for wood and value production, and helps reduce damage levels. If thinning is carried out too late, timber yields will be smaller at the time of final felling. With late thinnings there is also the risk that a stand may have started to stratify itself, meaning less freedom to select the best trees for retention. Holmen uses a thinning schedule called ‘Ingvar’, developed by the Forestry Research Institute of Sweden, as a tool to manage thinnings. The schedule is computer-based and can also be used to forecast stand development, enabling efficient silvicultural planning. Timing is important in thinning. The relation between upper height and basal area is critical. The schedule indicates when the stand is ready to be thinned. The schedule also indicates what the basal area should be after thinning. Keep in mind that the thinning schedule underestimates the site index for lodgepole pine by about three metres. The first thinning is normally done when the trees have reached an upper height of 12–14 metres, 11 metres for lodgepole pine. Second thinnings should be carried out before the stand is 20 metres high. Focused and concentrated conservation work increases

Planning thinning operations – Operational plans are done according to Holmen standards. – If possible, planning should be conducted when the ground is free of snow, to determine stand data, prescriptions and maps as needed. – Natural values should be assessed in areas where they may be expected to be high. Red-listed species and other valuable species should be registered in the stand catalogue. – The restrictions necessary for the preservation of natural values and cultural heritage sites should be clearly defined. These should include protected zones and biotopes with special needs as well as the location of future biotopes. – Future biotope locations should be located at readily identifiable spots, such as rocks, water hollows or groups of dead trees. – Residual stand density and species composition should be stated. If needed, sub-compartments can be created. The volume of extractable timber should be determined, as well as the average tree size. – The location of special passages and landings should be indicated in the instructions. – Investigate the need for temporary bridges and road reinforcement to reduce soil damage. – Make a rough pre-alignment of strip roads and tracks in areas susceptible to wind damage. – Indicate suitable locations for roadside landings. – Assess whether preparatory cutting is necessary. – No preparatory cutting close to edges and buffer zones. – Protected areas to be thinned in the interest of conservation should be indicated in the operational plan. – Where applicable, plan for clearing of ditches. Detailed planning – The load capacity of main hauling roads is of key importance. Alignment of older hauling roads should be critically viewed. – If strip and haul roads have to cross streams, construct log bridges. Place logging debris at bridge entrance and exit to reduce damage. – If the directive does not say otherwise, temporary bridges should be dismantled after thinning. What season is the best for thinning – For areas with soils of poor carrying capacity, thinning should be conducted when the ground is frozen or during dry spells. – Avoid thinning stratified stands with a large broadleaf component during the nesting season for birds, check on precautions for birds of prey.

Strip roads and winding tracks Terrain permitting, strip road distances may be increased by driving harvesters on what are termed ‘winding tracks’. This involves winding around main stems, making maximum use of the available gaps. Logs are fed from the track to the strip road. Small and mid-size harvesters can work from winding tracks. Winding tracks are not established in rocky and steep terrain. Strip roads should be aligned to optimise crane utilisation. It is essential to ensure that no zone is left unthinned. Operational costs and the risk of damage increase if incisions are made into the stand from strip roads. They sometimes still have to be made, however, where the terrain is very rocky or otherwise difficult.

Guidelines

for strip roads and winding tracks

Thinning with machinery operating on winding tracks is the preferred mode of work at Holmen in pine stands, terrain permitting of course. Strip road distance using mid-size harvesters is 30 metres, and for small harvesters 26 metres.

When working on winding tracks, use should be made of gaps already present. Main stems should not be touched unless absolutely necessary. Winding tracks should not be used in spruce stands, moist sites and sites with fine soils and wherever it is impossible to reinforce tracks with debris to reduce damage. Strip roads should have a spacing of 18–22 metres when systematically aligned. The maximum share of an area that can be covered by skid trails is 22%. This is to ensure that trees are removed/retained based on their properties rather than position. Plan carefully to avoid soil damage. Strip roads should be about 4 to 4.5 metres wide and as straight as possible, to reduce logging damage. Strip roads should not be aligned close to stand edges, as this could open up the stands, increasing susceptibility to wind damage. Plan carefully to avoid soil damage. No areas between strip roads should be left unthinned. Strip roads should be reinforced with logging debris whenever possible. Passages should be kept to a minimum, as should links between strip roads. Incisions should only be made in very rocky or difficult terrain.

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Thinning

Thinning

Forwarders in such operations should be able to work with a skid trail no wider than 4– 4.5 metres, without injuring trees next to the trail.

Accumulating harvester heads should be used in early thinning of pine stands.

Preparatory cutting Preparatory cutting of undergrowth enhances harvester performance and improves quality. Visibility is improved for the operator, enabling him to better apply the harvester unit to the trees. Preparatory cutting is mainly done in stands bigger than one hectare, or stands with areas needing the treatment of at least 0.5 hectares. When preparatory cutting is done, trees are often big enough for root rot to establish itself, and via roots spreading from tree to tree. Trees of commercial value should therefore be cut by the harvester to enable treatment against root rot. Preparatory cutting should, if possible, be done in winter when root rot does not spread.

Guidelines

for preparatory cutting in connection to thinning Stands with more than 6 000 stems per hectare higher than 0.5 metres, and 3 000 higher than 1.3 metres should be given priority. Trees of commercial value should not be cut.

Machinery used Thinning is dominated by mid-size harvesters. They are stable and strong enough for the loads to be expected. They can also be equipped with accumulating harvester heads. Mid-size harvesters can also operate from winding tracks as well as strip roads. Smaller harvesters are not competitive in thinning areas with larger stems or difficult terrain. They are also economically sensitive to long transports, meaning that a number of sites must be available in the areas they work in. Apart from that, small harvesters are well suited to early thinnings in pine stands provided that stems are small, stands are dense and diameter distribution is even.

Guidelines for choice of machinery

Spruce stands should be treated during winter. Observe conservation prescriptions. Concentrate cutting in areas with trees; no further opening is necessary in natural gaps and where visibility is good enough without cutting.

Mid-size harvesters are the machine type normally used for thinning. Small harvesters are suitable for first thinnings provided that stems are small (50%) and high site index (G26 or higher) are treated, if felling was carried out at temperatures exceeding five degrees Celsius. All coniferous stumps are treated. No treatment is done if stump harvesting is to be carried out. Objective: at least 90% cover on 90% of the stumps. Where present, larch will be treated like spruce.

is cross cut, it is debranched as far as possible. Tops not debranched can also be used.

Guidelines for harvesting forest residues Stands where forest residues are to be harvested should be treated with preparatory cutting to avoid pollution with dirt and gravel. Felling sites should be adapted to forest residue harvest. This means that tops and branches are piled. Avoid piling where there is dense undergrowth. Residues used to reinforce strip roads should be left in the forest. Make sure that stumps, burned wood and polluted residues are not piled. Forest residues can be harvested at mesic to moist sites of blueberry type or better. Stands with high spruce shares or pine stands on sites with high site indices should be given priority. Forest residues are not harvested on poor or wet sites, nor on peat soils, where harvest might implicate future growth reductions or extensive soil damage. Residue piles are hauled to a landing using a forwarder after needles have mainly fallen, normally one growing season after harvest. Conservation and heritage preservation done at the time of harvest should not be interfered with. Forest residues are not harvested on parts of the felling site where they are needed to increase the carrying capacity of the soil. Reducing soil damage has higher priority than maximising harvest of forest residues. Logging debris and timber used for soil protection close to watercourses and passages should be left in the forest, to help reduce damage in scarification. Ensure that tracks and hiking routes remain passable. Avoid driving across piles of residue, doing so may pollute them with mineral soil. Holmen harvests both green and brown forest residues, but strives to maximise the share of brown residues. Harvests, green as well as brown, are documented in the stand catalogue.

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Final Felling

Stump harvesting Stumps have high energy content, and it is therefore desirable to increase stump harvesting to cater for the needs of central heating stations. Main strip roads used for hauling timber, forest residues and stumps to landings are under a lot of pressure. No stump harvesting should be done on the strip roads to be used by the forwarder. Critical parts of the roads may need to be reinforced even before hauling has started. Areas suitable for stump harvest are areas with a high share of spruce with mesic conditions of blueberry type or better. Areas with broken or rocky terrain should be avoided.

Stump harvesting could contribute to reduced oil dependence. Norsjö, Västerbotten.

Final Felling

Guidelines for stump harvesting It is important that planning is done when the ground is free from snow. Decisions on whether to harvest stumps or not should be taken at the time of planning. Areas selected for stump harvesting should be dominated by spruce. Stumps harvested should be coniferous. Stumps of broadleaves are never harvested. No stump harvesting on lichen-rich land used for reindeer husbandry. No stump harvesting on peat soils, areas with shallow groundwater or next to watercourses. This is to avoid soil damage and disturbance to watercourses. Stumps are not harvested in the vicinity of major rocks, ant heaps, archaeological sites, lying dead trees and areas with conservation measures already taken. Conservation measures taken are not to be disturbed by stump harvesting. Stumps of broadleaves and small stumps (