Magazine article, 2013
Tarmvridrøn i Vendsyssel: fire års overlevelse, vækst og sundhed i en skovrejsningskultur på hævet havbund.Skovsgaard, Jens Peter; Graversgaard, H.C.; Skovsgaard, Tor
AbstractOur investigation comprised a plot of 1.15 ha in a stand established by planting during spring 2007 on former meadow land. The stand was established with six tree species, including a total of 87 Sorbus torminalis trees. The soil developed on a post-glacial, raised littoral seabed as a so-called A/C-soil with a thick layer of humus (A) over sand (C) and a high and fluctuating groundwater table (Figure 2). The height growth of Sorbus torminalis (26-40 cm per year, depending on the year) was almost at the same level as that of oak, sycamore and Norway spruce, and better than that of large-leaved lime and sweet chestnut. Already during the second year of growth some trees were taller than 1.3 m (Figure 1, HCG). The mortality of Sorbus torminalis was low (8 percent). During summer 2008 essentially all Sorbus trees suffered from bark browsing (Figure 3) by field vole (Microtus agrestis), but recovered completely. During autumn 2008 (and possibly also in other years) some Sorbus trees were damaged at the top by early frost (Figure 4). Most of them easily recovered, but the increasing tendency to forking is a concern. Initially the height growth of Sorbus torminalis correlated positively with the thickness of the humus layer, but later the correlation vanished. So far, the height growth of Sorbus torminalis was uncorrelated with terrain elevation (the variation across the plot was only 2 m) and geographic location on the plot. Four growth seasons after planting the tallest Sorbus torminalis had grown to 250 cm (Figure 5, TS, photographed after three years of growth). As far as we know there are no other examples of Sorbus torminalis growing on a raised littoral seabed, but it is known to thrive on dry and poor soils and on soils with stagnant groundwater. Investigations in France indicate that Sorbus torminalis can grow on marl soil with stagnant groundwater. We therefore believe that Sorbus torminalis should have the potential to remain in the stand together with oak as a main species.
2013, volume: 45, number: 2, pages: 84-88