VDI 3959 Blatt 1:2018-03

Nitrogen availability is one of the most important location factors that significantly controls the functions and species composition of the vegetation. As a result of emissions from agriculture and combustion, nitrogen compounds released from the air have long since exceeded the quantities provided by the natural cycle. While the input, availability and discharge of nitrogen can only be determined with great effort in selective case studies, the composition of the vegetation cover is an expression of nitrogen eutrophication. The application of the standard makes it possible to measure the effects of nitrogen accumulation on the composition and diversity of forest plants as a direct expression of nutrient availability. The intensity, speed and large-scale distribution of the effects must be demonstrated. The evaluation of the nitrogen indicator values of plant species is suitable for the detection of spatial gradients and temporal changes in the nitrogen supply, e. g. in the context of environmental monitoring programmes such as the Federal Forest Inventory, soil condition survey or the ecological area sample.