Research infrastructure

General

The Chair of Forest Growth and Dendroecology conducts research on a number of research sites. These experimental plots are studied using different methods depending on the research question. The majority of the experimental plots are located in forests. In addition to the experimental plots located in forests, the chair also analyses an agroforestry experimental plot. A selection of measurement methods and research sites is presented below.

Measurements

Dendrometer

To measure the growth of trees over time, dendrometers are attached to many trees on the research sites. Both circumference and point dendrometers are used. The picture shows a point dendrometer.

Measurements

Microcores

In order to investigate the process of xylogenesis (wood formation) at the cellular level, microcores are repeatedly removed from some locations. These are then prepared and analysed in the chair’s tree ring lab.

Research sites

Mathislewald

The University of Freiburg owns the Mathiswald forest near Hinterzarten with an area of 127 hectares as part of a foundation. In addition to its economic utilisation, the forest is also used for teaching and research purposes by the Faculty of Environment and Natural Resources. The Chair of Forest Growth and Dendroecology conducts research on the area and digitises the forest using remote sensing methods.

Research sites

Schönberg

The Schönberg research site (approx. 0.7 ha) serves to demonstrate the production of valuable timber with beech. The research focuses on the effects of heavy thinning on the radial growth of the remaining future trees (Z-trees); measurements began as early as 1992. The research site consists of two plots, one heavily thinned and one control plot. Silvicultural treatments are carried out in a cycle of 10 years to achieve the research objective. The trees are regularly measured using traditional and modern measurement methods.

Research sites

Möhringen

Our research sites in the Swabian Alb near Möhringen were established in the winter of 1998/99 along a valley on a dry-warm SW exposure and an opposite cool-moist NE exposure with a total size of 8.46 ha. Three different treatment variants were carried out on both sides (control, heavy thinning, very heavy thinning). The aim of the experiment is to better understand the growth of European beech at the cell, tree ring, individual tree and stand level as well as its drought stress tolerance in relation to thinning, site factors and genetic influences.

Research sites

Agroforestry research site in Breisach

Our agroforestry research site in Breisach am Rhein was established in 1997 to investigate the production of value wood in agroforestry systems. A number of specific management interventions, such as pruning, are required for value wood production. The main tree species on this site are wild cherry, oak, ash and sycamore. The trial area covers a total of around 2.5 ha.

Research sites

Altitude gradients in the Black Forest

The Chair of Forest Growth and Dendroecology currently operates a large number of dendroecological field measuring stations along four altitudinal gradients in the Black Forest (between 350 m and 1100 m altitude). Here, the seasonal growth dynamics and tree water deficit of the economically important tree species beech, spruce, fir and Douglas fir are continuously monitored with a total of 185 precision dendrometers in high temporal and spatial resolution. The formation of wood and bast cells along the height gradients are also be analysed by taking microcores weekly. The aim of the research sites is to gain in-depth insights into high-resolution growth reactions of the investigated tree species to weather extremes as well as past and predicted climate changes.

Terrestrial laserscanner

With the help of our terrestrial laser scanner, we can collect 3D data on individual trees and stands. The measurements are based on LiDAR (Light Detection And Ranging): Light is emitted and reflected by an object. The distance between the object and the scanner is calculated based on the time elapsed between the reflected light being emitted and received.

3D point clouds

The resulting point clouds have an accuracy in the millimetre range. A variety of parameters can be derived from the data to describe the 3D structures of individual trees and stands. An important advantage over manually recorded data is the repeatability of the data acquisition, which is not the case with destructive methods, for example for determining the biomass of trees.

General

The Chair of Forest Growth and Dendroecology runs a co-operative metal workshop together with the Chair of Environmental Meteorology. The workshop is particularly valuable for the manufacture, repair and improvement of measuring instruments.