AL4 Lichen pastures

>> Background information

Development

The long-term monitoring of the state of lichen grounds was initiated in 1995. Lichen grounds belonging to the 12 northernmost reindeer herding co-operatives have been inventoried three times by 2008. More than 95% of the total area of Finland's alpine habitats are situated within this area.

On the whole, the state of lichen grounds was quite weak in the mid 1990s and has continued deteriorate since. In the latest inventory from 2007-2008 half of the co-operatives' lichen grounds were assigned to the lowest quality class of the heavily depleted. In these areas there is less than 300 kg of lichen per hectare of alpine heath.

Impact of reindeer grazing

Reindeer grazing is the most important factor affecting the state of lichen pastures. Reindeer prefer certain lichens over others, and this selective grazing changes the species composition of lichen pastures. Reindeer lichens are in part replaced by for example species of cub lichens and snow lichens. Heavy grazing and large reindeer herds also cause erosion on the most sensitive sites. The scale of the impact depends on both the sizes of reindeer herds (see also AL1) and the grazing system.

In addition to reindeer grazing, alpine areas are affected by other eroding activities such as tourism (AL2) and off-road traffic (AL3). Long-distance transport of air pollutants may slow the growth rate of reindeer lichens. In the case of lichen pastures however, these seem to be either local or minor scale threats.