Conservation and Sustainable Use of the Biosphere - WBGU

Conservation and Sustainable Use of the Biosphere - WBGU

Spatial and temporal separation of biogeochemical conversion processes E 3.2


E 3.2.6

Spatial and temporal separation of

biogeochemical turnover processes in ecosystems:

The future

With the start of the Industrial Revolution, not only

was it possible to acquire larger quantities of fossil

and renewable raw materials more efficiently, but

their transport over long distances also became much

easier (ships, railways, trucks). However, as a result of

the improved transport possibilities, the spatial and

temporal separation of the biogeochemical turnover

processes was further accelerated and extended to a

global dimension. In addition to the substances

bound up with biomass, gases such as CO 2

,NH 3

,NO x

and SO 2,

were now emitted at higher levels, resulting

in a direct or indirect impact on the biosphere and

pollution of inland waters and shallow seas in coastal

areas, as a result of sewage from built-up areas and

agriculture (Paerl, 1993). Since most inland waters

are phosphorus-limited, phosphorus-rich sewage and

sediments make an especially high contribution to

eutrophication.Whereas the eutrophication of inland

lakes has considerably fallen in the industrialized

countries as a result of improved wastewater treatment

and the substitution of phosphates in detergents,

the problem is becoming much worse in developing

countries due to population growth and the

intensification of agriculture (Section E 2.3)

The dense transport network on land and water

and in the air allows the transport of very large quantities

of raw materials and food from all parts of the

world into the industrialized countries. Fig. E 3.2-2

shows the proportion of nitrogen used by the import

of fodder to EU agriculture.

The exporting countries thus suffer constant biogeochemical

depletion (the loss of phosphate is especially

serious) and, as a consequence, the acidification

of the soils, which is in contrast to a situation of ecologically

unsound biogeochemical accumulation in

the industrialized countries. Wilhelm Busch illustrated

this phenomenon very aptly in his picture

story Maler Klecksel (Painter Splodge) (Fig. E 3.2-3).

Another threatening trend can be seen in the

developing countries: the rapid emergence of megacities

is often linked to a rapid neglect of the rural

areas. People’s material need in rural areas leads to

serious symptoms of ecosystem degradation,

whereas in the built-up areas the uncontrolled accumulation

of waste is leading to eutrophication, is poisoning

soils and water bodies and is pushing out the

characteristic communities of organisms.

The geographical separation of chemical turnover

processes on the mainland leads to an increase in

nutrient inputs into water bodies. In this respect, the

natural eutrophication described above is exceeded

by several powers of ten (WBGU, 1998a).As a result

of the deterioration of the living conditions there is a

reduction in biological diversity, usable fish populations

are put at risk and other water functions are


Viewed in terms of biogeochemical cycles, the

‘recipient regions’ have developed into flowthrough

systems by decoupling cycles at the expense of ‘donor

regions’. In the process, large quantities of exhaust

gases, wastewater and solid waste arise that pollute

and change the environmental media that surround

them. The order of magnitude reached by human

influence can be seen in the global chemical conversion

of nitrogen and sulphur, which are already dominated

by man, and in the key changes to the carbon

and phosphorus cycles.

Figure E 3.2-2

Feedstuff imports into the

European Union in 1997.

Source: Mund, 1999











United Kingdom












0 50 100 150 200

Fodder imports [kg N ha -1 year -1 ]

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