Plants belonging to the heather family may be kept in good shape for years by the two elementary maintenance measures of weeding and trimming. In addition to weeding out unwanted species, annual trimming will keep the vegetation vigorous and will extend its vitality to a very long period. Without such maintenance measures, however, vegetation types like these may rarely be preserved.
The same is valid for ground covers composed of crowberry or billberry (Empetrum or Vaccinium spp.), but since trimming is, in this case, not required or tolerated, it will only rarely be necessary. When its vitality is reduced as a result of old age, frost or if a snow cover was trampled, Vaccinium vitis-idaea and V. myrtillus are cut back to the ground completely, after which a sprinkling of fresh peat applied in spring will provide new nutrients and will bring revitalisation. Small areas of heath and bog may thus last and remain in an attractive condition for many years. It is exactly their age that gives them their own special character and atmosphere. In these times of volatility and haste, these are remarkable forms of green, demonstrating how plantings on the one hand and natural growth on the other blend into a perfectly harmonious whole. They provide clear examples of the succession of vegetations, which is at the same time occurring elsewhere in the park as well.
In the formation of the mould layer of heath vegetations, mosses play an important role. Together they create a whole new growing environment on the substratum of, for example, poor peat or loamy soils: mats of roots, stalks and mosses, growing increasingly thicker as the vegetation ages. It provides an excellent environment for species such as Empetrum nigrum, Calluna vulgaris, Vaccinium myrtillus and V. macrocarpus. If the vegetation is not disturbed as it is growing older, these species will establish themselves spontaneously if they are found elsewhere in the park. In this manner, succession occurs, but, as in the other plant combinations in the park, in a manner that is different from the succession as it is seen in nature.
