At the moment, all County Forestry Boards are compiling systematic surveys and these are due for completion in 1997. The biggest companies and other big landowners are economically and practically responsible to conduct similar surveys under the superintendence of the Swedish Forestry Administration. The survey is carried out in two stages and begins with preparatory work indoors with the compiler researching a variety of sources for potential key habitats, e.g. infrared aerial photographs, forest inventories and forest management plans, information from landowners and non-governmental organisations and some different types of maps. The material is then assessed in the field and habitats with redlisted species are delimited and described as woodland key habitats. Occurrence of Key Habitats Preliminary results show that the total number of woodland key habitats in Sweden might be between 60-80 000.
Key habitats occur irregularly in the landscape.