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.
