Herb-rich forests are home to numerous endangered species

Herb-rich forests only account for around one per cent of our forests. However, herb-rich forests are an important habitat for numerous endangered forest species. In early 2021, the Finnish Forest Industries Federation launched an action programme for the management of herb-rich forests, with the goal of providing information about their importance to forest biodiversity and promoting management methods that aim to improve their condition. Another goal is to train forest sector employees so that they can better serve forest owners in questions related to herb-rich forests.

According to an assessment published in 2019, nearly half of endangered forest species live in herb-rich forests. The main causes of their endangerment include changes in the ratio of different tree species, forest renewal and management actions, as well as the decline in decaying wood, old forests and large trees.

The action programme for herb-rich forests is part of the forest industry’s joint forest environment programme launched in 2016. “The goal is to further improve the forest industry’s efforts in forest environment-related matters, as well as to promote active and open communication,” says Tiina Vuoristo, Sustainability Manager at the Finnish Forest Industries Federation.

“Herb-rich forests play a far greater role for biodiversity and endangered species than their surface area might lead you to believe. Nutrient-rich growth areas are populated by more species, and herb-rich forests are very important for endangered species in commercial forests,” says Janne Soimasuo, Development Manager at Metsä Group. “This was one of the reasons we joined the action programme for the management of herb-rich forests.”

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The large-flowered and herbaceous Cypripedium calceolus -orchic, a protected plant, thrives in Lapland's herb-rich forests.

Better service for forest owners

Tapio Palvelut Oy, a partner in the programme, is responsible for the action programme’s content. “We compile instructions and guidelines in an information package and provide an online course that offers further details to those engaged in practical work,” says Lauri Saaristo, a leading expert at Tapio Palvelut.

“The material improves the competence of forest professionals, and we hope it will help them to better identify herb-rich forests and the various alternatives for nature management,” Saaristo adds. While the action programme focuses on herb-rich forests in commercial forests, it is also important for professionals to identify other sites suitable for protection so they can offer forest owners the opportunities provided by the METSO programme.

The forest owner’s toolbox expands

Most herb-rich forests used to be cleared to make way for fields, as their nutrient-rich soil made them attractive to agriculture. The most representative of the remaining forests have been protected under the conservation programme for herb-rich forests. Those excluded from the programme are protected under section 10 of the Forest Act.

“Forest owners can also adopt the voluntary protection measures in the METSO programme, encouraging both the permanent and fixed-term protection of herb-rich forests,” says Saaristo.

“The action programme focuses on managing herb-rich forests within commercial forests. It promotes specific features characteristic of herb-rich forests, which can differ greatly from one area to the next,” says Soimasuo.

“For example, a valuable species that is found in a particular herb-rich forest and depends on broadleaved trees may suffer from the strong growth of spruce trees. In this case, spruce will be cut down more in this particular area, and broadleaved trees will be favoured instead.”

According to Soimasuo, by focusing on the management of herb-rich habitats in commercial forests and developing more tools to support this work, we can effectively improve the living conditions of endangered species.

For forest owners, this means more voluntary means of increasing forest biodiversity. Nature management actions are carried out in connection with other measures for commercial forests.

How can you identify a herb-rich forest?

Herb-rich forests are commonly thought to exist only in the southernmost parts of Finland However, they can be found as far north as Lapland. The vegetation in herb-rich forests varies geographically.

“Kitee, in North Karelia, for example, is home to magnificent herb-rich forests full of wolf’s bane. Broadleaved trees are typical along the southern coast. North Savo features natural herb-rich forests dominated by spruce, while slipper orchids and other special species are found in Lapland,” Saaristo explains.

Dwarf shrubs such as blueberry or lingonberry, which are typical of heath forests, are usually not found in herb-rich forests. Instead, they grow herbaceous flowering plants such as herb Paris, wonder violet or baneberry. The soil in herb-rich forests is also home to special species of fungi.

February daphne, fly honeysuckle and mountain currant are often found in the shrub layer of herb-rich forests. Compared to heath forests, herb-rich forests offer a more diverse growth environment for tree species. In addition to spruce and birch, herb-rich forests often grow common broadleaved trees, which are less valuable for commercial forestry, as well as rare broadleaved trees.

In southern Finland, the rarer species include maple and oak, as well as hazel, which is found here and there. Honeysuckle, guelder rose and roses may be found among spruces in herb-rich forests farther north.

Bird couples are more numerous in herb-rich forests, and more birds nest per hectare in herb-rich forests than in heath forests. “They offer more food and a more layered habitat. Features that attract birds can easily be added to commercial herb-rich forests,” says Vuoristo.

The article was published in issue 1/2021 of Metsä Group’s Viesti magazine. Text: Annamari Heikkinen