Towards critical levels for ammonia – a fumigation study

Ammonia (NH3) is emitted from agriculture and traffic and may have phytotoxic effects only at high concentrations. Nevertheless, chronic responses may occur in higher and lower plant species at slightly elevated levels near stables and major roads, but provisional critical levels rely only on a few experiments.

In order to gain more knowledge, we will expose a number of rare and protected Central European plant species to low concentrations of the gas in greenhouse compartments and will follow their responses over two seasons. Species stem from oligotrophic ecosystems, which host a high biodiversity and where critical loads for nutrient N are often exceeded.