Stellenausschreibungen und Abschlussarbeiten

Assesing morphological responses to climate variability in beech seedlings & saplings (Fagus sylvatica)


Extreme weather events, threaten the health and thus the ecosystem functioning of forests in central Europe. Seedlings and saplings play an important role in forming the forests of the future. Therefore, it is important to focus on these young trees, which are sensitive to microclimatic changes and may undergo natural selection. Beech saplings suffer from competition with grasses and brooms, which are more common under open canopy. Here microclimatic effects like increased light and higher temperatures are more pronounced. Hence studying seedling selection in the light of changing climate is important to understand the future composition of forests.

In the Swabian Alb, the Hainich-Dün and the Schorfheide-Chorin, we will collect beech seedlings and saplings from different light regimes to assess their phenotypic traits related to drought adaptation under experimental drought stress.

This thesis offers the opportunity to conduct fieldwork in the Biodiversity Exploratories (https://www.biodiversity-exploratories.de/en/), a long-term experiment situated in Germany, as well as the chance to visit the TUMmesa facility in Munich - a climate chamber where diverse climatic conditions can be simulated.

General Aim of the study

Assessing drought adapted phenotypic traits in beech seedlings from different light regimes.


1. Seedlings developing under open & closed canopies exhibit different growth rates and morphological traits.

2. Seedlings developing under closed canopy have reduced survival and growth under experimental drought.

 Material & Methods

1. Sample seedlings under different microclimatic conditions (open canopy vs. closed canopy areas).

2. Examine morphological traits of seedlings (e.g., height, leaf area, root/shoot ratio).

3. Utilize the TUMmesa facility in Munich to simulate drought stress and assess the response of seedlings to projected future climate scenarios, including changes in temperature, precipitation, and humidity.

4. Conduct statistical analyses to determine the relationships between forest management practices, microclimate conditions, morphological traits, and sapling survival, with the aim of identifying key factors influencing sapling recruitment and establishment.

Rough schedule

· Participation in fieldwork – transport of seedlings to Marburg starting April 15th.

· Examination of morphological traits of seedlings in Marburg in May/June 2024

· Drought stress experiment in the TUMmesa facility in Munich July/August 2024

· Analyses and writing of the thesis in Autumn/Winter 2024/2025

Important reading

1. Pfenninger, M. et al. (2021): Genomic basis for drought resistance in European beech forests threatened by climate change

2. Thom, D. et al (2020): Effects of disturbance patterns and deadwood on the microclimate in European beech forests

3. Leuschner (2020): Drought response of European beech (Fagus Sylvatica L.) - A review

Publication potential

· Co-authorship in publication in a recognized journal


Marieke Lenga, Mona Schreiber, Christian Lampei, Lars Opgenoorth