The original Finnish article by professor Ilkka Hanski was published in Helsingin Sanomat, January 9, 1999.

Man has changed the Finnish nature by many ways. Old, natural-state forest is the habitat that has decreased the most.

Every species from colibacterium to man has its own requirements for a suitable habitat. These requirements do not just pop out of the blue. Biological characteristics of species have been developped during millions of years and they do not change quickly.

Without its habitat no species can survive. This is a known fact, but there are many other things in the relation of the species and their habitat that is misinterpreted. It is widely assumed that if the individuals manage to move elsewhere when their original habitat disappears, there will not be any real harm done.

This conclusion is not correct. Even though individuals might manage to find another suitable site, there is no reason to presume that the population of the species will remain stable in the new surroundings.

For the long-term survival of the species, the total number of the population is significant, not the destiny of the individuals. A population smaller and more restricted in the area than ever before has a higher risk to disappear than a bigger population. There are hardly any exceptions to this common rule.

Another mistake is to assume that the future of the species adapted to a certain habitat is safeguarded, when a small amount of the original habitat is saved. For example, the assumption of the few protected natural-state old-growth forests preserving the future of the old-growth forest species in Southern Finland is based on this misinterpretation.

They do not. When a significant part of the habitat vanishes, a group of rare species disappears immediately, because they happened to exist only in the habitat now gone. These extinctions are called extinction costs.

The extinction cost usually covers only a small part of extinctions caused by the vanishing of the habitat. More important that the immediate extinction cost is the extinction debt.

Only one million hectares of old-growth forest left

The exticntion debt is caused by local populations decreasing too small to survive when the habitat vanishes or is fragmented. The disappearance of the remaining populations takes a while. But it will happen.

In prior to human influence at least half of the Finland's productive forest land was covered with old-growth forest; the rest represented younger stages of the natural forest succession.

Today old natural state (or close) forest only covers about 1,1 million hectares, i.e. 5,5 % of productive forest land. About 0,4 million hectares, 2 % of the productive forest land, have been protected.

The extinction debt can roughly be estimated by the dependance between the number of species and the land area. Let's presume that in natural state about one third would be old-growth forests. In Southern Finland old-growth forests cover only about 0,5 % of productive forest land, which means an extinction debt of about half of old-growth forest species. If 10 % of all about 2000 forest dwelling species are old-growth forest species, the extinction debt is 1000 species.

This may sound surprisingly high, but the facts proof that the magnitude is correct. Already one fourth of the threatened forest beetles have vanished from Southern Finland and even 75 % in the Southern coast.

Additional 1000 forest dwelling species have been evaluated to be endangered. This number includes only 42 % of Finland's species, since the knowledge of the rest is inadequate. This means that the number of endangered forest dwelling species can be estimated over 2000.

Vanished species will not come back

If the aim is to prevent the mass extinction of old-growth forest species, all the remaining somewhat natural-state old-growth forests have to be left out of commercial utilization. If the old-growth forests are still logged, the extinction cost has to be paid, and the less old-growth forest remains, the more extinction debt has to be taken.

Short-time joy causes not only temporary hangover, but also a permanent injury since the once vanished species do not come back. Even though the forests would grow they would become only nature's ghost towns, where there are no inhabitants behind the standing scenes.

For the forestry practices, regional politics and implementation of the protection aims it is problematic that the remaining old-growth forest is situated mainly in the Northern Finland. During the next couple of decades in many places in the Northern Finland there is little else to log except for the old-growth forests.

After few decades today's middle-aged forests will be ready to be logged and there will not be such a need to log the old-growth forests. The solutions that do not destroy the forest nature have to be found now.

In the Southern and Middle Finland the situation is disconsolate, since the total area of old-growth forest is catastrophically low, 0,5 % of the productive forest land. The enlargement of the small old-growth forest fragments have to start immediately.

Protection is a profitable investment

If the remainig old-growth forest are protected, the already hideous extinction debt will not grow anymore. Saving the old-growth forests gives us and the future generations time out: species not yet disappeared can be preserved.

Old-growth forests operate as havens and expansion centres for thousands of species that can succeed in lightly managed commercial forests where old trees, decaying wood and keybiotopes in their natural state are being left. The aim of the present-day forest policy is to improve such a forest management and to preserve as much of biodiversity in the commercial forest as possible. People are willing to even pay for this.

But even the lightly managed forests are not good enough for the actual old-growth forest species. The protection of old-growth forests cannot be compensated by the ecological landscape planning or other changes in management of commercial forests.

If a significant amount of old-growth forests in Russian Karelia disappears, the importance of the Finnish old-growth forests to the species and the biodiversity of this country is multiplied. There is also a reason to believe that the small economical value of natural-state forests in Finland is greater in the future than the amount gotten from destroying these forests now.

It is necessary to emphasize the great disproportion of the choices being made now. The old-growth forests that are not logged today can be in theory logged tomorrow, but the old-growth forests logged today, nor their species, will never come back.

 

>>> Part 2 of the article

>>> Background of forest protection

Translation by the Finnish Nature League