Magazine article, 2013
Tarmvridrøn i Ulvshale Skov på Møn: smuk, sjælden og dansk, men ignoreretGraversgaard, H.C.; Skovsgaard, Jens Peter
AbstractUlvshale Forest (c. 130 ha) is located in the northwest of the island of Møn in eastern Denmark. The forest grows on calcareous coastal shingle at an altitude of around 2 m above sea level. It is a mixed deciduous forest that was formerly grazed. Grazing was discontinued in the 1920s. Currently, pedunculate oak (Quercus robur), small-leaved lime (Tilia cordata), hornbeam (Carpinus betulus) and beech (Fagus sylvatica) are among the dominant tree species. The forest also includes sessile oak (Quercus petraea). Ulvshale Forest hosts Denmark's largest natural populations of small-leaved lime and wild service tree (Sorbus torminalis). The population of wild service tree is scattered throughout the forest and includes approximately 300 sizeable stems and around 1000 root suckers (2002-inventory). The maximum tree height for wild service tree in Ulvshale Forest has been measured at 17 m. The largest stem diameters at breast height measure around 35 cm (Figure 1). The maximum age has been estimated at 130-150 years. Regeneration: Wild service tree in Ulvshale Forest regenerates mainly from root suckers. Although some trees produce flowers on a regular basis natural regeneration from seed is essentially absent. In line with this recent research indicates a low genetic diversity for wild service tree on this location. Light: Most individuals of wild service tree in Ulvshale Forest suffer from shading from taller neighbour trees and adapt morphologically to these conditions (Figure 2). Their continued survival and morphological adaptation indicate a high degree of robustness and a strong survival potential. Health: Wild service tree in Ulvshale Forest looks remarkably healthy. This also holds for suppressed individuals, the crowns of which are generally well developed and with fresh green foliage. Browsing: The lack of natural regeneration of seed origin may, at least partially, be due to a high browsing pressure from roe deer, hare and rodents. Wind stability: Many large individuals of wild service tree in Ulvshale Forest have a leaning stem (Figure 1) and roots sticking out of the ground away from the lean (Figure 3). We believe that this could be due to the effect of one or more windstorms. Based on investigations of the root system of young seedlings (Figure 4) and suckers (Figure 5) we hypothesize that a sucker of wild service tree do not immediately develop a taproot and that the horizontal orientation of the lateral root from which a sucker originally develops may result in a reduction in wind stability for winds from directions perpendicular to the direction of the major lateral root. Depending on wind exposure this issue may be of major importance for the silvicultural potential of wild service tree in northern Europe. The silvicultural potential: For historical reasons and due to poor stem quality the immediate silvicultural potential of wild service tree in Ulvshale Forest is rather limited. Suitable tending of recent regeneration from root suckers could, however, result in the development of crop trees of commercial quality. No offspring from Ulvshale Forest has been tested or compared with wild service tree of other origin. The local population could be well adapted to northern Europe and we recommend including offspring from Ulvshale Forest in future genetic experiments. Future prospects: Ulvshale Forest has been unmanaged, or at least without commercial forestry activities, since the late 1920s. The forest is now part of the Natura-2000 programme. We strongly recommend selective thinning to promote the regeneration and survival of wild service tree in Ulvshale Forest.
2013, volume: 45, number: 1, pages: 22-25