Trees store climate and environmental information from the past within their annual growth rings. Physical measurements of annual ring parameters, such as ring width and density, or the concentrations of certain chemical elements of different masses (isotopes), form the basis for reconstructing past climate and environmental dynamics. To do this, these annual ring parameters are compared and calibrated with measurement data from instrumental observations.

With its over 200-year-old tree stock and the continuously operating climate station of the German Meteorological Service since 1893, the Telegrafenberg is an ideal location for the development of new measurement methods, calibration of tree ring data, the investigation of climate dynamics, and the impact of climate change on tree growth and forest health.

3-D seismometers, also known as geophones, are installed on trees to record seismic waveforms. Different seismic waves are generated by vibrations and movements of the trees, caused by the interaction of weather and environmental influences with the trees. Influencing factors include wind load, soil-root interaction, tree structure, tree water content, and tree health. As healthy trees often exhibit different vibration patterns than sick or weakened trees, it may be possible to detect early signs of stress or damage (e.g., drought stress) in trees.

Dendrometers are instruments for measuring the radius or diameter of trees. Here, radius dendrometers are used which measure the expansion or contraction at a specific point (radius) of the tree trunk every 30 minutes. Water loss through the transpiration of leaves and needles causes the elastic tissue of the tree trunk to contract and the trunk diameter to shrink during the day. At night, water uptake through the roots is greater than the water loss through the crown. This causes the tree trunk to expand. New wood cells (annual rings) are primarily formed at night, leading to an irreversible increase in the thickness of the tree trunk.