RE2 Soil extraction

>> Background information

Development

The use of rock materials is strongly dependent on the construction and building activity and it reflects the economic circumstances. During economic recession in the beginning of the 1990s the total rock material consumption decreased but started to grow again after mid-1990s. In 2007 the level of 1990 was exceeded. Nevertheless, in 2009 the rock material consumption decreased again due to poor economic circumstances.

The use of gravel and sand remained at the same level 1990?2008, but in 2009 it decreased by one third, equaling 35 million tons annually in recent years. The use of crushed bedrock grew quite steadily since 1990 until 2008. In 2009 it decreased somewhat but has increased again slightly after that.

Regionally the total extraction of rock materials is quite uneven. The extraction is largest in Uusimaa, Ostrobothnia, Häme and south-western Finland. In the eastern Finland the extraction is relatively low.

Impact on biodiversity

Gravel and sand pits are located ordinarily in esker areas. Eskers were formed in the end of the latest ice age as the glacier slowly withdrew. Eskers consist of gravel and sand depositions. The conditions in esker habitats vary widely compared to the surrounding area. Many species are specialized to these circumstances and are not found elsewhere.

Taking of gravel and sand destroys suitable habitats for esker species. Additionally, the thinning of soil and disappearing vegetation cause risks to groundwater. Groundwater contamination can also be due to an old habit to dump waste on gravel pits. Nevertheless, some esker species flourish also in gravel pits and gravel pit walls are suitable nesting habitats for sand martin.

Only a relatively thin layer of soil has been developed in Finland after the latest ice age. Thus there is large proportion of bare rock formations, about 3 % of the whole area. Growing circumstances vary greatly on different rock types and the rocky habitats support a variation of specialized species. The increasing use of crushed rock material is threatening many rocky habitats. Especially large is the threat in the surroundings of densely populated areas.