Environmental Engineering Reference
In-Depth Information
On the occasion of the Year of Biodiversity, a study was prepared on Soil Biodiver-
sity (2010) about its functions, threats and tools for policy makers about the state of
knowledge of soil biodiversity, its functions, its contribution to ecosystem services and
its relevance for the sustainability of human society. Soils are the habitat of more than
one-fourth of all living species on earth, and one teaspoon of garden soil may contain
thousands of species, hundreds of millions or even billions of individuals, hundred
meters of fungal filament networks, 1-2 tonnes in mass per ha.
A comprehensive European study on the mitigation of the adverse effects of Soil
Sealing (2013) showed that permanent covering of soil with impermeable layers causes
an irreversible loss of the ecological functions of soil. Soil sealing inhibits free infiltra-
tion and evaporation and increases runoff and floods. Between 1990 and 2000, at least
1,000 km
2
of soil surface was sealed per year, which is the area of Cyprus. Between
2000 and 2006, the average increase in artificial areas in the EU was 3% (252 ha per
day). The average degree of soil sealing in the European cities ranges between 50 and
250 m
2
/capita, while the percentage of sealing varies between 20 and 80%. The latter
depends largely on how compact the city structure is. In largely compact towns with
a high degree of soil sealing, but low per capita value (Bucharest, Tirana or Athens),
the area outside the city is kept for other uses. The opposite trend is to enlarge city
area with a low sealing percentage but high per capita value for instance in Helsinki,
Oslo or Vaduz. As a result of this concept ecosystem function will be altered on an
extended area.
Contamination has been a priority issue in the European soil policy. Figure 7.1
shows the management scheme of contaminated sites in the EU (Soil Protection, 2007).
Figure 7.1
Management scheme of contaminated sites in Europe.
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