After the mould layer of organic debris under the older woods has formed and matured, all sorts of woody plants will appear spontaneously. These may be pioneers, such as alder, rowan, mespil and aronia, or species of mature woods, such as oak, ash, hawthorn, hornbeam, beech, field maple, holly, yew and ivy. Other non-indigenous species, such as crabtree, rhododendron, privet, barberry, horse chestnut and prunus species, are often imported from elsewhere. In this manner, rejuvenation is almost spontaneous. With the exception of the exotic species, which are removed when weeding, seedlings of indigenous species that fit into the image one has in mind are carefully retained. These seedlings contribute to a lively and dynamic appearance of the woodland areas. One treats these newcomers the same way one treats planted seedlings. One can, however, rarely allow the retained seedlings to over dominate the image. To avoid too great a disruption of the park’s image, one will strive to replace woodland on a small scale, in stages if necessary. Depending on the situation, the herbaceous layer will be taken up and planted again on the spot. Sometimes skimming off the surface of the mould layer, containing seeds, bulbs and spores is a useful method. New young trees are then planted into this layer.