The study of a seventy years old stand of Scots pine on drift sands proves that Scots pine growth on these sites was and is still relatively good: average diameter 27.6 cm, average height 19.4 m, standing volume 213 m3 and an annual increment of 4.9 m3.ha-1.yr-1. All Scots pines belong to the upper storey. Yet considerable differences in crown development and vitality are observed. The current growth rate and the spontaneous settlement of pine seedlings under canopy show the ideal conditions for the creation of a high forest with reserves. Anyway a rotation period of more than 70 years is recommendable. On several places a consolidated regeneration of Scots pine seedlings under canopy occur. Groups with a stem number of 700 to 3,500 seedlings per are, ranging in age from 3 to 11 years and in height from 10 to 170 cm, are present. This Scots pine regeneration has developed in a normal mor humus layer and in a dense Deschampsia mat. Broadleaved regeneration is not so abundant, and consists for 75 % of black cherry. Absence of seed trees, browsing damage and the exclusive character of black cherry are the limiting factors for the installation and survival of valuable indigenous species, such as pedunculate oak. Provided that black cherry is removed and that the regeneration is protected against wild damage, it is possible to create a mixed forest dominated by Scots pine but with a considerable admixture of indigenous broadleaved trees. However, if black cherry will not be sufficiently controlled, it can be expected that in a first phase black cherry will dominate the understorey, that it will prevent the regeneration of all other species and that, very soon, it will form an almost single-species dominated stage in forest succession.
Unsupervised spectral-spatial processing of drone imagery for identification of pine seedlings
