RE8 Red-listed rocky and esker habitat types

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Development

A red-list assessment of Finland's habitat types was published in 2008. Approximately one fifth of all rocky habitats were considered endangered. Endangered categories are critically endangered, endangered and vulnerable. Rocky habitats were divided into five groups: acidic and intermediate basic rock outcrops, calcareous rock outcrops, serpentinite rock outcrops, scree and rocky habitat complexes.

The most endangered habitat were the calcareous rock outcrops. Calcareous rock outcrops are very nutritious and many specialized species live on those areas. Calcium reduces soil acidity and releases nutrients for plants. Calcareous rock outcrops are endangered mainly because of mining, building and overgrowing plant cover.

Serpentinite rocks are ultra-alkaline and the vegetation is quite sparse. They are mainly populated by specialized species that have adapted to these demanding circumstances. Finland?s serpentinite rocks have been evaluated either vulnerable or near-threatened. The main threat is mining: soapstone mines are the most common, but serpentinite rock areas are usually also rich ore deposits. The surface area of both calcareous and serpentinite rock outcrops is quite small.

70 % of scree habitats were evaluated as "least concern" - thus their situation is quite stable. Ancient shore screes and calcareous and serpentinite boulders were considered near-threatened.

Acidic and intermediate basic rock outcrops cover over 99 % of all rocky habitats? surface area. None of acidic or intermediate basic rock outcrops have been estimated endangered. Near-threatened habitats are for example disintegrated rocks, shady precipices and most shore rocky habitats.

All rocky habitat complexes belong to the category "least concern". Rocky habitat complexes are canyons, ravines, caves and clefts in the rock.