INCREASE OF BIODIVERSITY IN HOMOGENEOUS SCOTS PINE STANDS BY AN ECOLOGICALLY DIVERSIFIED MANAGEMENT

Three important parameters of biodiversity in first generation Scots p ine (Pinus sylvestris) forests on sandy soils have been evaluated: her bal layer diversity, natural regeneration and stand structure. The stu dy took place in the Belgian Campine region, where the original oak-bi rch forest, degraded to heathlands in the course of time, were finally replaced by monocultures of Scots pine. These first generation pine f orests are characterized by a low biodiversity. In maturing stands of this type, however, a spontaneous increase of biodiversity is noticed. Herbal species richness is very limited in all age classes. Different natural regeneration patterns are found. Referring to stand structure , the lengthening of the rotation favours the ingrowth of several hard wood species. As a consequence, the homogenous Scots pine stands are g radually and spontaneously transformed into heterogeneous mixed stands , featuring a noticeable increase in biodiversity. Selected human inte rventions may further increase biodiversity. The fundamental managemen t principles are discussed: avoidance of major disturbances, lengtheni ng of the rotation period, use of native tree species and natural rege neration, protection of microbiotopes and permanent monitoring.