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Leif Nutto e Gere Becker

Senior Consultant at Unique Land Use GmbH, and Professor at the University of Freiburg, Germany


Timber harvesting in Europe and Scandinavia

Abstract: Europe is a Continent with a great variation of natural conditions (climate, soil, forest ecosystems) and shows very diverse structures of the forest - wood sector.

Most Scandinavian Countries show flat or hilly terrain, and natural forest ecosystems are dominated by only a few species (spruce, pine and birch), with relatively slow growth rates (MAI 4-9 m3/ha/y) which results in long rotations (50 -100 years) and small dimensions of the final crop trees (DBH 30 – 45 cm). Harvesting operations cover big areas (up to 100 ha and more), products are sawlogs in standard length, pulp wood and (from logging residues) wood chips for energy. Soils are sandy or frozen, when harvested in wintertime. Forests are owned and managed by either wood-pulp industry or private owners who team up in cooperatives.

These conditions and structures typical for Scandinavia favor the use of fully mechanized harvesting systems (harvester/forwarder), which are quite similar to the systems employed in Brazilian Plantation Forestry. Recent trends of technical development show bigger machines (8 or even 10 wheels), (partly) autonomously operating machines, guided by high resolution GPS and LIDAR, better support of the operators by a set of automated features (cross cutting, measuring, soil sensors etc.)

Forest conditions in Central Europe are quite different from Scandinavia. Germany with a total of 10.9 million ha of forests and a growing stock of 3.505 billion m³ is No. 1 in Central Europe and a good example to highlight this variety and the consequences for the applied harvesting system.

The terrain of forest areas is usually classified according to slope: from 0 to 25% wheel-based machinery and skidding lines are used, from 25 to 50% slope parallel skidding roads are built and road wheel-based machinery with security winches are used and over 50% - 60% cable yarding systems become standard. The conifer species Spruce (25%), Pine (22%), other conifers (7%), show an MAI of 9-18 m3/ha/yr. The broadleaved species are Beech (15%), Oak (10%) and other broadleaves (18%), with a MAI of 6-12 m3/ha/yr. After stand structure 24 % are classified as pure stands and 76 % as mixed stands. National inventory shows an average standing volume of 380 m³/ha.

The ownership structure is as follows: 40% of the forest land is concentrated in enterprises of 1000 ha and more (10 state owned regional forest enterprises and a few big private owners), 36% in units between 20 to 1000 ha (communities and private) and 24% in units  between 1-20 ha (private, including small farmers). A significant part of the smaller holdings are members of in forest cooperatives and are managed following a common concept.

In management different approaches depending on ownership (public/private) may be identified: After planting or natural regeneration 5 or more interventions (thinnings) are conducted until reaching a rotation of 80 years for spruce and up to 150 years for beech and oak. Final cut consists of a few small clearcuts (below 1 ha), while in continuous forestry target diameter harvesting is practiced. Harvested volume in 2020 was about 80.4 million m³ of wood, with 87% of conifers and 13% of broadleaves (sawlogs 59%, wood for board industry, pulp wood and wood for energy 41%).

Severe and frequent draught periods in the last years resulted in increasing unplanned cuts (salvage fellings) mainly of spruce which in some regions exceeded the regular cuts substantially.   

About 60 to 75 % of the annual volume cut is harvested with fully mechanized systems (harvester/forwarder & skidder).  Restrictions are not only the steepness of the terrain, but also small cutting areas and volumes, mixed stands and frequent selective thinnings. Also, the typically big dimensions of final cut trees (often more than 4 m³/tree) with big crowns result in technical limitations for harvesters and their boom. Furthermore appr. 20% of the harvested log volume is not cut into standard length but processed as long stem (up to 18 m length), because sawmills prefer to crosscut them individually following the demands of their production.

Consequently harvesters are either small (for selective thinnings) or very heavy with booms up to 10 m, often mounted on track carriage, to handle the big tree dimensions in selective final cuts over natural regeneration. A significant proportion of the felling is still done by chain saws, and logging equipment is using winches, often combined with grapples, to handle these products.

To operate technically viably and economically successful under these conditions, a dense permanent network of truck roads (25 to 45 m/ha) and skidding roads or -lines (additional 50-100 m/ha) is standard, which results in forwarding distances between 20 m (flat terrain) and 50-80 m length (steep terrain). The movements of big machines is restricted to this permanent network, uncontrolled driving on the forest floor is prohibited to protect the soil structure and the growth of the neighboring stand.

In 2017 about 400 units of specific forest machinery have been sold (30% harvesters, 30% forwarders and 40% of special forest tractors with winches and/or grapples in Germany.

This heavy forest equipment is in most cases not owned by the forest enterprises, but by small to medium independent forest contractors, who often compete for processing orders on a case to case basis. Normally they operate at regional level, but depending on the wood market and special regional demand, f. e. after damaging events, they are also prepared to travel long distances following attractive harvesting orders. FSC-CoC certification is an important requirement when operating on public forest land.

Future developments take into account the rising awareness of forest owners and public stakeholders regarding ecology and climate change effects on the forests:

Soil and water protection requirements ask for systems with reduced impact on the forest soil. Small machines equipped with tracks and winches without driver, remotely operated by accompanying ground staff, are under development and tested for reduced impact logging in small scale continuous cover silvicultural systems. Forwarders with automatic cable assistance allow operations in steep terrain with reduced ground pressure and slip. In very steep terrain, chain saw felling and cable logging combined with a truck mounted processor unit (so called Mountain Harvesters) operating from forest roads (in most cases uphill) is a common method.

To prepare and control operations in difficult terrain and stand conditions, GPS-GIS Solutions combined with the deployment of drones are becoming standard.

To operate carefully and maintain advanced harvesting technology, educated and well trained staff is an indispensable requirement. Given the fact that working conditions in the forest environment are often difficult and dangerous, the recruitment and motivation of well-trained employees becomes a major challenge especially in rural areas for both forest enterprises and their service providers.