Hauptinhalt

Available theses (in the case of interest, get in touch with Anna)

Loss of seed dormancy during agricultural seed propagation in rare agricultural weeds (BSc or MSc)

Extinct plant populations can be actively reintroduced by sowing seeds. The seed for reintroduction is commonly propagated at agricultural fields. During this process, seed dormancy may be lost. At the same time, seed dormancy is important for the survival of populations in disturbed environments. Rare arable weeds grow on arable land, an environment that is regularly disturbed, so loss of dormancy could affect the long-term survival of reintroduced populations. At the same time, rare arable weeds are nearly extinct and reintroduction efforts are common. This thesis will investigate whether seed dormancy is lost during the propagation process.

What is it good for: Improving seed production for reintroduction or rare weeds
Methods – germination experiments in a climate cabinet
Time schedule: autumn/winter/spring (independent of growing season)
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

Is regional seed still suitable for use under ongoing climate change? (MSc)

Plant populations are often re-established using local or regional seed because local populations may be adapted to local conditions. Current legislation in Germany mandates use of regional seed. However, climate change alters local conditions and the adaptation of regional populations might lag behind. Local or regional seed might thus be suboptimal for use in restoration. The thesis will investigate whether the plants from regional seeds are still adapted to regional conditions, or lags behind.

What is it good for: Test of suitability of regional seed for restoration under climate change.
Methods: common garden experiments in the botanical garden
Time schedule: spring and early summer (depends on growing season)
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

How do forest wildflowers respond to climate change over the last century? (MSc)

Flowering times of plants are shifting due to climate warming — but how much, and why? Herbarium specimens offer a unique long-term record of plant phenology. This thesis revisits and extents a large-scale European herbarium dataset (>6000 specimens of spring-flowering forest herbs) to investigate changes in flowering time over the past century. For the first time, this thesis will incorporate detailed forest microclimate data instead of the coarser macroclimatic data used previously. This allows for a more realistic understanding of how understory plants respond to warming within their actual environments.

What is it good for: Understanding plant responses to climate change
Methods: Data analysis in R, spatial modelling
Time schedule: Flexible (e.g. start in Fall 2025)
You should bring: some skills in R, and motivation to work with spatial and historical data (and possibly learn some Baysian statistics)
Contact: Franziska Willems (franziska.willems@uni-marburg.de)

Is seed longevity in storage heritable? (BSc or MSc)

Seed storage in seed banks is an important method of ex-situ conservation. However, the seed in the seed banks slowly deteriorate and die. For effective conservation, we need to understand how long seeds stay viable. Seeds of different species differ in their longevity in storage. However, there is also substantial variability between seed batches of the very same species. It is unclear whether this variability is caused by maternal environment, or it is heritable. The thesis will test, for one to three species, whether seed longevity in storage is heritable. Specifically, it will investigate whether offspring on plants grown from long-lived seeds also produce long-lived seeds.

What is it good for: Understanding of seed storage behaviors in conservation seed bank
Methods: germination experiments, possibly greenhouse experiment
Time schedule: autumn/winter/spring (partially dependent growing season)
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de), Lea Klepka (lea.klepka@biologie.uni-marburg.de)

Does climate change give new opportunities to the weed Hordeum murinum (MSc)

Hordeum murinum is a ruderal plant that apparently profits from climate change, likely because drought caused by climate change created gaps in existing vegetation. The thesis will use seeding experiment around Marburg to test whether the species can better establish in environments that are increasingly common under climate change. The work involves doing vegetation records, so it requires basic knowledge of plants or willingness to learn them, in order to produce reliable data.

What is it good for: Understanding what limits spread of expansive plant under climate change
Methods: field experiment around Marburg
Time schedule: summer 2025 (seed collection), early autumn 2025 (seeding), spring 2026 (data recording)
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de), Helene Villhauer (helene.villhauer@biologie.uni-marburg.de)

The effect of mowing time on the breeding success of the little owl (MSc)

The little owl (Athene noctua) depends on extensively managed meadows and orchard grasslands – but how does the timing of mowing affect its breeding success? This thesis uses data from a long-term monitoring program in North Rhine-Westphalia (Germany) and satellite base information of mowing times to analyze how mowing schedules influence nest box use and breeding outcomes. The aim is to develop evidence-based recommendations for little owl-friendly land management – with real-world relevance for conservation practice.

What is it good for: Improving conservation measures for the little owl through better-informed mowing strategies
Methods: Data analysis in R, statistical evaluation of breeding records and mowing times
Time schedule: Flexible (e.g., starting in fall 2025)
You should bring: some skills in R, and motivation to work with ecological datasets
Contact: Franziska Willems (franziska.willems@uni-marburg.de)

The effect of fen restoration on ground dwelling invertebrates – carabid beetles and spiders (2 MSc)

The study focuses on fen restoration in Burgwald. Fens in Burgwald were drained and afforested with spruce many decades ago, which led to massive degradation. Over the last 40 years, there have been continuous restoration effort and over 20 degraded fens have been restored. Restoration has a positive effect on vegetation. Yet, the effect on invertebrates, especially insects, is unknown. These theses will focus on the effect of fen restoration on ground-dwelling invertebrates, e.g. carabid beetles and spiders. The candidates will place pitfall traps on site, regularly empty them over the season and sort the insects. Co-supervised by Dr. Martin Brändle.

What is it good for: Understanding the effect of fen restoration
Methods: Field work in Burgwald (bike or car required), sorting insect in lab.
Time schedule: spring-autumn 2026 for field work and insect sorting
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)
Requirements: mobility (bike, car), basic knowledge of insect or willingness to learn

Herbivory along restored small streams (BSc or MSc)

River restoration aims to improve water retention in the landscape and the ecological value of water bodies around the globe. In Europe, most restoration projects focus on small streams, yet the ecological benefits of such projects are poorly documented. In this project we investigate, how restoration affects the terrestrial biota. For the thesis the specific question is, how herbivory is affected by restoration. For this, we place white clover (Trifolium repens) in pots along restored and unrestored small stream sections around Hesse. After a defined time of exposure, we will visually estimate the herbivory. The results will indicate whether restoration affects herbivory pressure.

What is it good for: Evaluating ecological benefits of restoration for herbivory patterns
Methods: growing plants in the greenhouse/fieldwork on the streams/estimating herbivory
Requirements: Car
Time schedule: spring/summer/autumn 2026
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

How do old grass stripes affect herbivory intensity? (BSc)

Many nature conservation measures in grasslands involve reduction of mowing intensity. The most extreme case are old grass stripes, when part of meadow is not mown for up to several years, with the aim to support insects and birds. Insects are important herbivores. This thesis will investigate the effect of old grass stripes on herbivory intensity and pathogen infestation. It will place potted Trifolium repens plants in old grass stripe vegetation and assess the herbivore intensity.

What is it good for: Understanding the effect of conservation measures
Methods: growing plants in the greenhouse/fieldwork in meadows in Radehäuser Lache (Amöneburg)
Time schedule: spring 2026
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

How do old grass stripes affect vegetation composition? (BSc)

Many nature conservation measures in grasslands involve reduction of mowing intensity. The most extreme case are old grass stripes, when part of meadow is not mown for up to several years. While this can have positive effect on birds and insects, can have a negative effect on plants. After the stripe is mown again, the vegetation might recover. This thesis will take place in Radehäuser Laache and will study the effect of old grass stripes on vegetation and how vegetation recovers after the stripe was mown again.

What is it good for: Understanding th effects of old grass stripes on vegetation
Methods: vegetation record
Time schedule: May-June 2026
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

Pollination success of white clover along restored small streams (BSc or MSc)

Trifolium repens is an outcrossing plant that depends on insect pollinators to produce seeds. In this thesis, we assess whether restoration of small streams affects pollination success. We use potted Trifolium repens plants (same as in the herbivory experiment) and place them along restored and unrestored stream sections. After the flowering period, we will quantify the seed production as a proxy for pollination success. This will help to understand whether and how restoration influences pollinator activity.

What is it good for: Evaluating ecological benefits of restoration for pollination services
Methods: growing plants in the greenhouse/fieldwork on the streams/seed counting
Requirements: Car
Time schedule: spring/summer/autumn 2026
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

How successful are reintroductions of Arnica montana in Hessen? (MSc)

Arnica montana is an iconic species typical for low productive grasslands with frequent disturbances. Because of lack of suitable management, the species is rapidly disappearing, and there have been multiple projects that aimed on reintroduction or enhancement of populations in Hessen. The Botanical Garden of the Philipps Universität Marburg plays an important role in the reintroduction efforts, as it propagates small plants of Arnica that are later planted on site. However, the success of the reintroductions is rarely monitored, and there is no systematic database of reintroduction efforts. This thesis will gather information on reintroductions of Arnica montana over the last few decades, and verify their success in the field.

What is it good for: understanding the effectiveness of reintroduction of rare species
Methods: communication with stakeholders to gather information, field work
Requirements: Excellent communication skills, persistence, car
Time schedule: Autumn 2025-Spring 2026 (gather information), May – June 2026 field work.
Contact: Sascha Liepelt (sascha.liepelt@biologie.uni-marburg.de), Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

Does seed storage in seed banks conserve genetic variability? (2 x BSc)

Seed storage in seed banks is a crucial method of ex-situ species conservation, as it attempts to conserve seeds as genetic resources. However, even under optimal storage conditions, seeds slowly deteriorate and die. This mortality in storage might affect some ecotypes more than others, which would result in non-random loss of genetic variability. However, we do not know how commonly this happens across species. These theses will focus on how mortality in storage affect plant traits, and how these changes persist across generations.

What is it good for: Understanding the evolutionary consequences of seed storage
Methods: Germination experiment, Common garden experiment (greenhouse and outdoor), Trait measurements (germination traits, adult plant traits)
Time schedule: spring/summer (partially dependent on growing season)
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de), Lea Klepka (lea.klepka@biologie.uni-marburg.de)

The effect of large forest animals on vegetation of small water bodies (MSc)

Small water bodies (Tümpel) are commonly established as support for amphibians. However, these water bodies typically rapidly overgrow by vegetation and lose their function. Large forest animals use these water bodies, disturb the shores, and possibly slow down the succession. This thesis will investigate the effect of large forest animals on the vegetation. It will take advantage of a system of small water bodies that have been partially fences as prevention of amphibian predation (another thesis supervised by Prof. Thorn).

What is it good for: Management of small water bodies
Methods: Vegetation records in the field (May-June 2026)
Time schedule: spring/summer 2026
Requirements: Car, willingness to work in remote places, being fine with very basic accommodation
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

Differentiation of populations in rare agricultural weeds (MSc)

Plant populations are commonly re-established using local or regional seed, because local populations might be locally adapted. The local adaptation is stronger in some species than another. It is unclear whether there is local adaptation in (rare) arable weeds, because seeds of these plants have been commonly transported with crops like grains on larger distances. The thesis will study whether populations of arable weeds are phenotypically differentiated.

What is it good for: understanding plant evolution
Methods: common garden experiment
Time schedule: spring and early summer (depends on growing season)
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

Current and future climatic niche of Hordeum murinum (MSc)

Hordeum murinum is a ruderal plant that apparently profits from climate change, likely because drought caused by climate change created gaps in existing vegetation. The thesis will use species distribution models to identify the climatic niche of Hordeum murinum, and how it will shift under different climatic scenarios. As it is mainly modelling, it would be good if the candidate has already some coding skills (in R). Co-supervised by Prof. Zizka.

What is it good for: Understanding future spread of a weedy plant
Methods: modelling
Time schedule: flexible
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de)

Phenotypic differentiation of populations of Arnica montana in Hessen (MSc)

What is it good for: Understanding future spread of a weedy plant
Methods: Common garden experiment
Time schedule: Winter – Summer 2026
Contact: Anna Bucharova (anna.lampei-bucharova@uni-marburg.de),