FA5 Field clearance and afforestation

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Development

Since the beginning of the 1990s, the total field area has changed only by a few percent yet the turnover of field area has been greater. New fields are cleared  and existing fields taken into other uses as a result of afforestation and construction.

Since 1990 a considerable area of new field has been cleared although annual data exists only for years 1996?2004.  During those years annual clearances ranged between 10 000 and 27 000 hectares. In relation to existing field area most of the new fields were cleared in Lapland, Kainuu, North Ostrobothnia and North Savo.

Large scale afforestation of fields has been used to limit agricultural overproduction since the beginning of 1960s when the state begun to support afforestation. Since the middle of the 1990s the annual area of afforestation has remained less than 10 000 hectares. As another effort to control the increase in field area the conditions for the EU agri-environmental aid have been tightened for new fields in the 21st century.

Impact on biodiversity

Fields are often cleared in fertile forests and peatlands such as herb rich forests and rich fens. Clearing has had a considerable effect on the occurrence of species living in these habitats. For example, numerous occurrences of the now endangered lady's-slipper and marsh saxifrage have been destroyed.

Afforested fields may be valuable for nature conservation if they develop into herb rich forests. However, forested fields should not be compared with natural forests as such since field management changes physical and chemical soil characteristics of fields so that they differ from those of forests. Field species are often able to survive in the newly formed forest for decades and thus increase its species richness. Large amount of nutrients remaining in the soil also increases the number of species. Several game species like brown hare, partridge and white-tailed deer benefit from fields that are left unmanaged. On the other hand afforestation is harmful to many field species which depend on open habitats.