The effects of acid deposition (acid rain) are strongest on poor soils with low buffering capacity, which are traditionally in use for forestry, and on lakes. The acid increases the mobilisation of trace elements and Al, decreases the uptake of nutritive elements by the root system, and renders species such as trees, more vulnerable to attack by fungi, bacteria, etc. Besides the environmental harm the economic consequences of damaged forests (effect on prices of wood, increased risk of avalanches, decrease of touristic appeal) and dead lakes (loss of fish production, harmful effects of mobilised trace metals on potential drinking water) are considerable.
In order to save forests and lakes fertilisation with dolomite can help if the acidification of the damage to trees is in a relatively early stage. Estimates of forest damage are made mainly on a visual basis, which is time consuming, requires experienced inspectors and has a poor reproducibility in time. Recently a correlation between the content of nutritive elements (Mn, N, P, K, Mg), indicator elements (eg Al, S, F) in tree leaves or needles, and the health of the tree has been established, which allows to use chemical methods to assess the health of forest. Reference materials consequently were requested to compare the situation of forests of different types in different countries to allow correct assessment of trend in forest damage.
Indicator elements such as Al, Cl, S (damage) and P, N, Mg, Ca, K and Mn (nutritive state) were certified in beech leaves and spruce needles (first year's generation) taken from moderately affected forests NNE of the Ruhr-area (D).
Two reference materials - beech leaves spruce needles - (CRM 100 and 101) were certified in 1989, EUR 12680 EN.
Funding SchemeCSC - Cost-sharing contracts