Marine and terrestrial flora
Trollfjell Geopark is in the North-east Atlantic boreal region. The marine flora and fauna are dominated by species which, from the viewpoint of Nordic conditions, have a southerly distribution or are distributed along the entire coast, whereas only a small proportion have a clear northerly distribution. The marine areas along the coast and the shallow waters are very valuable and productive from a global viewpoint. Measured as biomass, productivity in the shallow water is comparable with that in the most productive agricultural areas.
Trollfjell Geopark is on the northernmost edge of the heathland distribution, but even here sheep are able to graze on the heaths all year round. The coastal heathland ecosystem is today classified as critically endangered and areas on Leka and Vega are designated as nationally important and protected as nature reserves.
A very unusual kind of forest, the boreal rainforest, is found in coastal parts of central Norway. It is dominated by Norway spruce, but also contains some deciduous trees like grey alder, birch, goat willow, rowan and aspen. It grows in moist areas with high precipitation. In this moist, cool environment, an absolutely unique biodiversity has developed, particularly noted for many species of lichen. Boreal rainforest is classified as an endangered type of habitat today, and is on the Norwegian Red List. Trollfjell Geopark has several nature reserves with boreal rainforest.
Trollfjell Geopark also has several rare examples of broad-leaved deciduous woodland made possible so far north by a mild climate near the sea. The broad-leaved deciduous woodland in Moaksla Nature Reserve in Brønnøy is one of the areas in the geopark with the richest flora, including the northernmost occurrence of small-leaved lime in the world. Other nature reserves in the area with broad-leaved deciduous woodland mainly have such trees as bay willow, hazel and wych elm. Sorbus neglecta, an endemic species of rowan, grows very locally in Nordland. It is a 1-4 m tall tree or shrub which has its core area in Reppen Nature Reserve in Bindal.
The strandflat islands with their wetland areas, salt marshes, seaweed banks and shallow waters rich in fish provide ideal conditions for a large population of birds. The 222 bird species recorded in this area is an extremely large number for an area this far north. The large population of common eiders is perhaps the best known of the marine birds, since eiders have been tended as semi-domestic birds for centuries to harvest their eggs and down.
The archipelago has the largest breeding population of greylag geese in Norway, and a large part of the world population of barnacle geese rests here during the spring and autumn migrations. The cormorant colony is the world’s largest. Black guillemots, common guillemots, velvet scoters, Atlantic puffins, common terns and arctic terns are some of the other birds found here. The majestic white-tailed eagles are an obvious part of the landscape picture in the archipelago. Many nature reserves and bird sanctuaries are found on the coast, and Trollfjell Geopark has three RAMSAR areas : Horsvær, Horta and Sklinna.