Magazine article, 2013
Tarmvridrøn i Tyskland - 2. Skovdyrkning.Graversgaard, H.C.; Skovsgaard, Jens Peter
AbstractWild service tree receives much attention in German silviculture, but is rarely planted. Four examples illustrate some of the challenges with wild service tree. Example 1 - A mixed plantation problem In 1979 wild service tree was planted in a mixed forest experiment near Lutter in Lower Saxony. The stand was established as single-tree mix of wild service tree (every other tree in the row), beech, cherry, sycamore, field maple and small-leaved lime. The spacing was 1.5 m x 0.9 m. We visited the experiment in 2011. The stand was clearly under-thinned and wild service tree generally had straight stems and fewer forks than in an adjacent provenance experiment (Skoven 2013/5). In accordance with observations of mixed forest experiments with wild service tree in Denmark (Skoven 2013/2, 3 and 4) there appears to be a need for early interventions in planted stands that include wild service tree (Figure 1, showing a wild service tree in need of crown release). Example 2 - A near-natural mixture In 2004 a mixed stand of wild service tree, hornbeam and field maple was planted near Sailershausen in northern Bavaria. The stand was established as a row-wise mix of wild service tree and hornbeam with groups of field maple (Figure 2). The management objective is to produce high-quality timber of wild service tree, while hornbeam and field maple are 'serving' species. Due to the strong focus on wild service tree at Sailershausen this objective can undoubtedly be fulfilled. However, we generally recommend including oak (the usual main companion species for this type of mixture) as an insurance against unforeseen problems. On wind-exposed sites we furthermore recommend including a slow-growing conifer such as cypress to provide lee (for improved growth) and shade (against epicormic branches on the oak). Example 3 - Sailershausen: optimal site and silviculture for wild service tree Sailershausen Forest Estate (2,200 ha) is owned by the University of Würzburg. Oak is a main species, but wild service tree also contributes substantially to the economic revenue. Wild service tree is found mainly on calcareous sites. It is being regenerated through natural seed fall as well as from root suckers. It is now also being planted in reforestations to increase its share of the forest area (Figure 3). The estate maintains a standing stock of more than 1,500 wild service trees with a dbh of over 30 cm. These are clearly marked and numbered to avoid mistakes during forest operations and to allow for regular inventory updates and improved growth and harvesting prognoses (Figure 4, dbh = 46,5 cm, height = 32 m). High-quality timber of wild service tree is auctioned and sells at an average of 600 €/m3, with top prices going up to 14,500 €/m3. Example 4 - QD silviculture The state forests of Rhineland-Palatinate are managed according to so-called QD silviculture. Q stands for qualifying and D stands for dimensioning. First, trees qualify for quality through natural pruning. Next, pre-selected trees are thinned for selectively to allow for maximum diameter growth. Thinnings are usually initiated when natural pruning has reached 25 percent of the expected final height. The number of pre-selected crop trees may be as low as 40-50 per ha (Figure 5, showing a wild service tree (T) and a cherry (K) at too close range). When looking up in the canopy, the crown of a crop tree should be surrounded by an unbroken ring of blue sky. The idea is that this will ensure optimal crown development, thereby utilizing the full growth potential of the best trees. The QD concept is considered very suitable for wild service tree.
2013, volume: 45, number: 9, pages: 395-399