Report: Researchers surprised at range of species in Finnish commercial forests – see lengthy list
Finnish commercial forests are unexpectedly rich in species, according to a unique report by Metsähallitus.
A new report by Metsähallitus records over seven thousand observations on various species, of which 1,700 concerned occurrences of threatened species. A total of 133 species were found, 101 among them being endangered or near-threatened. The report focused on commercial forests and surveyed species of lichens, polypores and mosses inhabiting live and decayed trees.
’Overall, the result was a positive surprise. We found a great number of species, and each was observed more often than expected. We gained new information on the species and their occurrences in commercial forests,’ says Tuomas Kallio, Species Specialist at Metsähallitus.
The report was published at a webinar by Metsähallitus on 15 May. The range of species found is in general use as an indicator of the nature and protection values of forests. According to Kallio, these species form an essential share of forest species, which has been assumed to have deteriorated in consequence of forest use.
As the authority managing state forests in Finland, Metsähallitus surveyed the occurrence of threatened species on 230 sites in Lapland, Kainuu and Finnish Lakeland during the two years preceding 2023,
’There have been no extensive surveys of threatened species in commercial forests. Data of this type is important when assessing which species can be maintained in commercial forests and also the success of nature management,’ Kallio says.
Essential part of forest species included
According to Kallio, endangered and other species included in the so-called Red List can be found in many types of forests, even in ordinary commercial forests.
Commercial forests do not constitute what is called a species vacuum. With the help of nature management, it is possible to maintain suitable environments in commercial forests and provide support to protected areas.
’Commercial forests do not constitute what is called a species vacuum. With the help of nature management, it is possible to maintain suitable environments in commercial forests and provide support to protected areas. For particular species to occur in commercial forests, it is important that the forests contain characteristics necessary for each species, such as decayed wood, aged trees and broadleaves,’ Kallio says.
Kallio explains that most species on the Red List occur in many places, even though the number of individuals is small in the majority of cases.
’Not all the species are particularly demanding, so they may thrive in many types of forests. For some of the demanding species, the occurrences are clearly more frequent in old-growth forests, and it’s only fairly infrequently that they can be found in commercial forests.’
Survey sites chosen at random
The sites surveyed were forest compartments chosen at random. Over half of them (64 percent) were below 80 years of age and about one fifth (22 percent) between the ages of 20 and 80. Fourteen percent of the sites were over 120 years of age.
’Most sites were what we call normal commercial forests, meaning that they have the usual history of regeneration and thinning,’ Kallio says.
According to Kallio, the species surveyed can be found in any forest regardless of age, but the number of species was found to increase with the age of the dominant trees on a site.
The nature sites in commercial forests contained a wide range of species, with a great significance for the protection of biodiversity. The nature sites contained more species and species of a more demanding kind than sites in ordinary commercial forests.
The majority of observations concerned epiphytic lichen living on tree stems and branches. Fewer observations were made on species inhabiting decayed wood. A positive surprise was the presence of aged trees and broadleaves.
’In general, decayed wood is scarce in commercial forests, and so there were fewer observations on species inhabiting deadwood than of species inhabiting the stems and branches of living trees. Endangered polypores, for example, were only found on a few sites,’ Kallio says.
Lessons for forest management
The report inspires Tuomas Kallio to reiterate that one of the things to pay attention to with fellings is the number and type of retention trees.
’It’s particularly important to spare aged trees. Broadleaves must be spared at all stages of forest management, unnecessary clearing should be avoided, and sparing existing decayed wood is a cost-effective method of increasing forest biodiversity,’ Kallio lists.
It’s particularly important to spare aged trees. Broadleaves must be spared at all stages of forest management, unnecessary clearing should be avoided, and sparing existing decayed wood is a cost-effective method of increasing forest biodiversity.
The survey was a project of Metsähallitus Forestry Ltd, with the practical work undertaken by species specialists at Metsähallitus together with external species specialists. The project recently received the Environmental and Innovation Award of Metsähallitus.
