Norway has only a few square kilometres of "olivine forest". It lies on the west coast between Sunnmøre and Nordfjord; most of the forest is in Bjørkedalen in Volda. According to the Norwegian Environment Agency, the so-called olivine forest is a very special natural feature that is seriously under threat. The forest's special and distinctive "character" is determined by its growing conditions – it grows on rock containing the mineral olivine. Pines growing on olivine-bearing rock become tall and magnificent. The same is true of a number of other, likewise very special species. "Similar growing conditions can also be found in the Urals and in New Zealand," emphasises Tor Erik Brandrud, a researcher at the Norwegian Institute for Nature Research (NINA).

What is olivine?

The word "olivine" refers both to a mineral and to a rock, a rare type of rock that forms deep in the earth's crust. Olivine is one of Norway's most important industrial minerals. According to the Geological Survey of Norway, Norwegians supply roughly half of the world's mined olivine. The mineral contains large quantities of iron and magnesium, as well as rarer elements such as chromium, cobalt and nickel. Olivine is moss-green in colour, it is popular as a gemstone in jewellery making, and it is used in applications that must withstand great heat, such as the manufacture of bricks for fireplaces and smelting furnaces.

For many years Norway made wide use of olivine sand, which absorbs heavy metals well and is highly useful for capping contaminated sites at old mines, shooting ranges and ports.

Pines, fungi and ferns

"Olivine forests" grow on bedrock rich in magnesium and iron. Since these forests consist mostly of pine, they are called olivine pine forests, and they are also home to ferns that researchers call olivine indicator species, such as the brown spleenwort (Asplenium adulterinum), the green spleenwort and the shiny spleenwort. These are species or varieties that are partly or wholly tied to olivine-bearing soil. A characteristic feature of olivine pine forests is exposed rock, which supports rich biological diversity.

The "olivine forest" is home to red helleborines – orchids with purple-red flowers that thrive in limy soil – as well as other rare orchids. Thanks to the abundant magnesium, which produces a lime-like effect, fungi also grow in these forests.

A forest under threat

When the Norwegian Biodiversity Information Centre published its new Red List of habitats at the end of 2025, 40% of them were classified as threatened. The "olivine forest" was not included in that list.

"That is a pity, because we need all the knowledge we can get about the state of this threatened forest," says Tor Erik Brandrud. "Olivine forests are unique, diverse and among the most threatened forest habitats in Norway, where there is probably no other forest type that has been affected to the same degree by mining and other land-use activities."

An international responsibility

Olivine forests are classified as a habitat type that must be managed with particular care under special guidelines. Brandrud believes that Norway has an international responsibility to protect these forests. The main threats come from mining, logging and road use. Industry wants to extract the olivine, and the movement of heavy transport affects the environment. Grazing and the spread of invasive species add further pressure. "The threats really are quite serious," says Brandrud, who believes that olivine forests should most likely be added to the list of especially threatened habitats.

Differences between olivine pine forests

Some "olivine forests" are considered rich, others poor. In the poor forests species diversity is lower, because the humus layer is thick and the bedrock lies deeper. These areas resemble "ordinary" pine forests. The rich olivine forests, by contrast, have great species diversity, because the fertile layer is thinner. In some places the rock is exposed, and it is precisely there that the ferns, fungi and orchids grow. "It is important to preserve the rich olivine forests with their special, irreplaceable diversity," emphasises Tor Erik Brandrud.