Shoot growth
 

Shoot growth is a sensitive indicator for stress. In beech, a distinct relation can be observed between shoot growth on the one hand and drought, fructification and ozone load on the other hand. However, the reaction is one year shifted in beech as can be observed after the dry summer 2003: shoot growth of Norway spruce was depressed in 2003 whereas beech reacted only 2004.
Shoot harvest by helicopter.
     Time course of factors which are predictors for beech shoot growth between 1993 and 1998 (black year scale) and of shoot growth between 1994 and 1999 (green year scale).
Shoot growth of beech (red) and of Norway spruce (green).
 Stem increment
The stem diameter of the trees is measured at marked points with a millimeter calliper every four years. Increment results from the difference of the measurements. Stem growth of beech decreased between 1998 and 2006.  
Time course of volume increment for beech.

By means of an epidemiological data evaluation relationships between stem increment and stress factors can be observed.
The higher the ozone load during the increment period, the lower was the stem increment of beech.
Stem increment of beech was lower on soils with a low base saturation.