Nitrogen deposition on heathland lakes

Developments in nitrogen deposition

In virtually all heathland lakes, the supply of nitrogen through the air (deposition) exceeds the level at which there is a negative impact on plants and animals, the "critical deposition value". Of all water systems, heathland lakes are the most sensitive for nitrogen. Given the fact that most bog pools are hydrologically isolated, supply through the air is the main source of nitrogen in heathland lakes. When deposition levels are too high, acidification-sensitive plants disappear, endangering the reproduction of amphibians.
Control measures such as chopping down trees near to heathland lakes and removing flora on the banks can make heathland lakes less sensitive to nitrogen deposition.

Policy

The policy focus is to keep atmospheric deposition to a maximum of 1,600 mol of nitrogen per hectare annually in 2000.

• Nitrogen deposition in the Netherlands, 2001

Technical note

The critical deposition level resulting in negative effects has been calculated for every bog pool. This depends on, for example, the size of the bog pool, the flora on the banks and the distance to woodland. The critical deposition level is compared to the actual deposition, which is also calculated.

The AquAcid model is used to calculate the critical deposition.

References

• RIVM (2001). Bouwstenen voor het NMP4. Aanvulling op de Nationale Milieuverkenning 4. RIVM (rapportnr. 408 129 022), Bilthoven.

Relevant sections and indicators in the Environmental Data Compendium

• Nitrogen deposition in the Netherlands, 2001
• Environmental pressure in the Netherlands, Eutrophication theme: introduction and policy
• Eutrophying discharges in the Netherlands, 1980-2001 (page is not available yet)
• Eutrophying emissions to water, 1990-2001
• Discussion of Overview of environmental themes and impact on nature in the Netherlands
• Eutrophication and the presence of water fowl in the lakes between the old coastline and reclaimed land (page is not available yet)
• Eutrophication of marine water and the occurrence of algae (page is not available yet)