The even-aged, dominantly spruce stands in the (formerly heavilly polluted) Jizera Mts on the Czech-Polish border need a diversification in terms of age, structure and species composition. It is not an easy task because of extreme microclimate, acidified soils and damage to plants inflicted by rodents and deer.
In 2007, a project aimed at diversification of local ecosystems was initiated. The project is based on a system of diversification centres and corridors containing the species admixture (broadleaves and silver fir) protected from game, to form a web enriching the age and spatial structure of forests on the upper plateau and complement their species composition. The initial centres and corridors were placed on more sheltered places. Through silvicultural measures, the web successively becomes denser and expands also to less environmentally protected sites. The large-sized transplants (< 100 cm) combine with the standard planting stock within the project. Supportive measures such as initial fertilization of plantations and biochemical amelioration of depleted soils have been tested as well. Our paper describes the project principles, summarises the promising experience and selected research results after more than a decade of realisation.