New method and criteria for national assessments of threatened habitat types

Consistent information on threatened habitat types is needed for land use planning and for prioritizing conservation, management, and restoration actions. However, detailed background data for assessing extinction risks of habitat types exists only in few countries. We present a new, flexible procedure for assigning habitat types into Red List Categories similar to those used for species by the World Conservation Union (IUCN). The procedure allows variation in the character or scale of assessment units and it is applicable even with incomplete data. The assessment protocol consists of two primary criteria: the change in the quantity and the change in the quality of the habitat type. The criteria are analyzed by expert groups with a transparent and repeatable stepwise procedure. The quantitative and qualitative changes in habitat types over the last 50 years serve as a starting point for the assessment, and the status is adjusted by assessing sub-criteria that address earlier changes, predicted future change, and the overall commonness or rarity of the habitat type. We also report the main results of the first assessment of threatened habitat types in Finland, and illustrate the application of the criteria by two case studies.