5% of forest areas are home to 50% of threatened forest species. A recently conducted analysis of the Finnish Red List reveals which forest types would benefit most from protection.
The Red List, compiled according to criteria set by the International Union for Conservation of Nature (IUCN), is widely and best known as a list of threatened species, but primarily, it is an important source of information for planning biodiversity conservation.
The Finnish Red List has been studied by Petri Heinonen*, who argues that by using the information included in it, the targeting of nature conservation measures could be improved, along with the corresponding results. P. Heinonen has long-term experience as an environmental expert in the forestry sector. An analysis of the Finnish Red List conducted by him was recently published on the website forest.fi.
The latest assessment of threatened species in Finland was published in 2019. The Finnish Ministry of the Environment has commissioned similar assessments since 1985, making it perhaps the most comprehensive and longest-running assessment of the status or threatened nature of species in the world. P. Heinonen believes that the information and messages of the Red List are not taken into account sufficiently when planning environmental protection, and even less so in public debates. A good example of this is the choice of what to protect. According to P. Heinonen, most of the protected areas in Finland are located in heath forests, and proposals for new protected areas most often include this specific forest type.
“In reality, the threat to species is much greater on rock outcrops and mountain tops where trees do not grow, as well as in traditional agricultural habitats. Speaking of forests, the biggest problem is in grass-herb forests and eskers, which are home to about half of the threatened forest species, even though they represent only about 5% of the total forest area,” says P. Heinonen.
Protection of grass-herb forests and eskers** requires nature management
More than 40% of threatened forest species are found in grass-herb forests, which account for ~2% of the total forest area. A large number of threatened species are also found in eskers and other sunny forest territories, the total area of which is small. Therefore, more attention should be paid to threatened species in grass-herb forests, eskers, and the traditional agricultural environment, believes P. Heinonen, although the creation of protected sites should not be the only conservation measure.
“To ensure the viability of species in these areas, active measures are needed. If you leave a grass-herb forest to its own devices, the spruce will take over, and other species characteristic of such a forest will suffer. Species that grow on eskers require forest fires to reduce shading and 'awaken' the seed bank in the soil. The same effect can be achieved by intensively tilling the soil and reducing canopy cover,” explains P. Heinonen. The biodiversity of traditional agricultural habitats can also only be maintained through management; otherwise, they will gradually become overgrown. Species found in open clearings are in the most difficult situation, as the only effective way to protect them is to halt global warming.
A lot of forest means a lot of threatened forest species
Overall, the problem of threatened species in the Finnish natural environment is becoming increasingly serious. It is a frequent topic of discussion, and according to Petri Heinonen, this is justified.
“People mostly cite or use forests as an example, although the proportion of threatened forest species out of all assessed species has decreased with every new assessment,” notes P. Heinonen. 3/4 of Finland’s land area is covered by forests. The share of all forest species assessed in the Red List is 50%, but the share of threatened forest species is lower: approximately 38%. In all habitats, the ratio of threatened species to the total habitat area in forests is actually the best. Admittedly, the absolute number of threatened species in forests is the highest, but researchers explain this simply: the total number of species in forests is the highest because Finland has a great deal of forest.
The causes of threatened status do not align with developments observed in forests
The Red List also examines the causes of threatened status for various species and potential risks. According to P. Heinonen, these do not correspond to developments in Finnish forests, taking into account, for example, the National Forest Inventory (NFI). According to Red List data, 40% of threatened species are endangered by the decrease in old forests and large trees, and 32% by the decrease in the volume of deadwood. According to NFI data, old forests have not disappeared in Southern Finland; on the contrary, forests in this part of the country have been aging for at least the last hundred years. In Northern Finland, old forests have become rarer since the Second World War.
The territory that is considered Southern Finland in calculations is the territory south of the Oulujoki River.
On the other hand, large trees have not become less common, but their number has increased since the 1920s. The number of old trees has remained constant since the 1970s. In Southern Finland, the volume of deadwood remained relatively constant for a long time, but since the turn of the millennium, its volume per hectare has more than doubled. In Northern Finland, the volume of deadwood decreased for several years; now this trend has changed, and its volume is many times greater than in Southern Finland.
The Finnish Forest Research Institute, the predecessor to the Natural Resources Institute Finland, began estimating the volume of deadwood that could be used for firewood in the 1930s. Until the 1970s and 80s, these volumes decreased, but then started to increase again: in Southern Finland, they are twice as large as in the 1930s, and in Northern Finland, they are slightly smaller than in the 1930s, although still larger than in the south. A frequently cited cause of threatened status is the decrease in broad-leaved trees, although their number has actually increased.
P. Heinonen believes that in the future, when assessing threatened status, factors should be studied that helped maintain species ranges in Southern Finland even at a time when the amounts of deadwood, large trees, and broad-leaved trees were lower than they are today.
The total area of clearings has not increased over 50 years
According to Petri Heinonen, the Red List does not include a detailed description of how the causes of threatened status and risk factors are determined. Furthermore, he points out that some of them are described so generally that it is impossible to conclude how species ranges could be restored. The list of causes and risk factors has not changed since 1985. P. Heinonen believes that it should be re-evaluated.
A frequently mentioned cause of threatened status in public debates is more frequent logging. It is true that its volumes have increased in terms of the amount of timber harvested, but for biodiversity, the size of the areas harvested is more important. If we look at regeneration felling, which is considered the most harmful to biodiversity, its area has not consistently increased for at least 50 years. This apparent contradiction is explained by the fact that the number of trees in Finnish forests has increased by almost 70% during these same 50 years.
“Especially regarding regeneration felling, the average net volume of timber per hectare has increased in the same proportion,” says P. Heinonen.
For answers to be credible, they must be understandable
According to Petri Heinonen, the contradictions (even conflicts) between the assessments of threatened species and habitats are particularly striking. “According to the publication 'Threatened Habitat Types in Finland 2018', almost 90% of habitat types in heath forests are threatened, but only 6% of the species that primarily live in heath forests are threatened.”
A habitat type classified as threatened is in danger of extinction
“How is one to understand the information that almost all habitat types in heath forests are in danger of extinction, while at the same time only one in twenty of the species living there is in danger of extinction?” wonders P. Heinonen. He believes that both the Finnish Red List and the enormous work it has required are valuable in themselves; the book is also important because essential aspects of Finnish life depend on the well-being of nature and forests.
“The gap between the contents of the Red List and actual development is constantly widening. If we want to maintain the high assessment of the Red List and its credibility, understandable answers must be provided to the questions raised by its content,” says P. Heinonen.
“It is necessary for researchers to define the main goals for resource use and conservation measures, both of which can only be limited, in order to ensure maximum benefit at minimum cost,” concludes Petri Heinonen.
* Petri Heinonen. Bachelor of Forestry with long-term work experience in the forest sector both in Finland and abroad. Almost 30 years of experience in forest inventory, forest use planning, timber procurement chains, and environmental management in forestry, working for companies such as Metsähallitus and UPM. Work with forest inventory in Tanzania and Nepal. Member (also secretary) of Finnish forestry and forest policy planning working groups at the Ministry of Agriculture and Forestry and the Ministry of the Environment.
**esker, oss – a long, winding, narrow ridge-like hill consisting of sand, gravel, and pebbles deposited by glacial meltwater in a crevasse or tunnel of a glacier.