Of Finland’s deer species – moose, white-tailed deer, roe deer, wild forest reindeer, and domesticated reindeer – the one that causes the most damage in forests is moose. The 11th National Forest Inventory (NFI10) established that, between 2009 and 2013, moose had damaged seedlings across an area of approximately 520,000 hectares. Damage was recorded in approximately 16% of young pine stands.
Hunting appears to have reduced the amount of damage caused by moose in recent years. In addition to moose, some damage to forests is also caused by white-tailed deer, roe deer, and reindeer. Moose mostly damage forests by snapping off the top shoots of seedlings, but their tendency also to debark on more mature trees can also result in considerable damage. The most typical damage stand by moose are Scots pine-dominated stands with seedlings measuring between one and three metres.
Roe deer and white-tailed deer usually damage smaller seedlings than moose. Serious damage caused by these species in mainland Finland has so far been mostly limited to the areas with the densest populations. Roe deer have cause considerable damage to young coniferous stands on the Åland Islands. In northern Finland, reindeer feed on leaves in the summer, which is why silver birch in particular is slow to reproduce in the reindeer herding region.
Research to reduce moose damage in forests
The Natural Resources Institute Finland studies how deer choose their habitat and food and the effects of these factors on forests and the forest industry. National Forest Inventories produce a wide range of data on the scale of moose damage in different kinds of forests. Research themes include, among others, the habitats favoured by moose at different times of the year, factors affecting the scale and risk of moose damage, the effect of deer browsing on the forest ecosystem, and methods to reduce moose damage. Other subjects studied include the long-term effects of moose damage on forest growth and productivity as well as the grade of the harvested timber. Research projects are carried out in collaboration with several Finnish universities.
Picture on top of the page: Erkki Oksanen, Luke