1. PriOrity Effect Mechanisms (POEM)

DFG Projekt POEM ©T. Niemeyer / Leuphana
Forschungsfläche POEM Niederhaverbeck

1. PriOrity Effect Mechanisms (POEM)

Bachelor and master projects carried out as part of the POEM project will use a unique grassland field experiment set up in 2020 by our research group in Niederhaverbeck, in the Lüneburger Heide. The main objective of this experiment is to understand better how the order of arrival of three plant functional groups (forbs, grasses, and legumes) affect the structure and functioning of dry grassland plant communities (both aboveground and belowground).

Project 1.1: How does plant functional group order of arrival during assembly affect carbon and nitrogen leaching in a grassland field experiment?

This project will consist of the following tasks: (1) collecting soil solution samples from the experimental plots at specific time points using suction cups, (2) process the samples in the lab and measure a number of important chemical parameters (pH, nitrate concentration, and dissolved organic N/C concentration), (3) analyse the data and interpret the results, and (4) present your findings in a bachelor or master thesis written as a scientific paper.

Car driving license: Yes

Contact: Benjamin Delory (Benjamin.Delory@leuphana.de) and Vicky Temperton (Vicky.Temperton@leuphana.de)

 

Project 1.2: How does plant functional group order of arrival during assembly affect the structure and functioning of dry grassland plant communities?

This project will consist of the following tasks: (1) collecting the plant biomass of each individual species located inside randomly positioned quadrats in our experimental plots (harvests organised in July/August), (2) process the samples in the lab (drying biomass) and measure the total shoot dry weight of each species in each quadrat, (3) analyse the data and interpret the results, and (4) present your findings in a bachelor or master thesis written as a scientific paper.

Car driving license: Yes

Contact: Benjamin Delory (Benjamin.Delory@leuphana.de) and Vicky Temperton (Vicky.Temperton@leuphana.de)

 

Project 1.3: How does plant functional group order of arrival during assembly affect plant functional traits?

This project will consist of the following tasks: (1) measuring one whole plant trait (plant height) and 5 leaf traits (area of a leaf, leaf dry-matter content, specific leaf area, and carbon and nitrogen content) on all target species that managed to establish, (2) process leaf samples in the lab (measuring leaf area, drying biomass, measuring leaf C/N content), (3) analyse the data and interpret the results, and (4) present your findings in a bachelor or master thesis written as a scientific paper.

Car driving license: Yes

Contact: Benjamin Delory (Benjamin.Delory@leuphana.de) and Vicky Temperton (Vicky.Temperton@leuphana.de)

 

Project 1.4: How does plant functional group order of arrival during assembly affect root productivity and vertical root distribution of dry grassland plant communities?

This project will consist of the following tasks: (1) regularly taking high resolution pictures of roots growing at different depths along minirhizotron tubes installed in our experimental plots using a state of the art camera (VSI-BARTZ MS-190). During the growing season, root images quill be acquired every two weeks; (2) classifying and annotating root images taken in the field, (3) segmenting roots present in the images using a manual root image analysis software (rhizoTrak) and/or software tools relying on deep machine learning, (4) calculate root traits (e.g., total root length in each image, growth rate, etc.), and (5) present your findings in a bachelor or master thesis written as a scientific paper.

Car driving license: Yes

Contact: Benjamin Delory (Benjamin.Delory@leuphana.de) and Vicky Temperton (Vicky.Temperton@leuphana.de)

3. Flower strips in agricultural Landscapes

Project 3.1: Availability and diversity of floral resources on annual and perennial flower strips in agricultural landscapes (one Bachelor thesis)

  • Timeframe: Fieldwork: June – August (4 full days in total), Data processing and analysis is decoupled from fieldwork and can be done later.
  • Study sites: 6 plots with different flower strips in the region of Ammerland and Hude (near Oldenburg). Driving there by car, ideally together with other students, is required. If possible, an institute car will be provided. Due to the current Corona situation, the ability to use a private car is beneficial. Travel expenses would be covered.
  • Fieldwork extent: A total of 4 fieldwork days at intervals of 2-3 weeks between June and August. Bird’s eye view pictures of vegetation square meters in different types of flower strips will be taken and plant species identification is required.
  • Herbarium: of plant species that are not easy to identify on the spot is to be created.
  • Data processing: Counting and identification of flowers on the pictures.
  • Statistical Analysis: Calculating floral display and diversity indices. Instructed implementation of generalised mixed effects models using the software R.

Contact: Swantje Grabener: swantje.grabener@leuphana.de

 

Project 3.2: Flower visitation networks of potential pollinators on annual and perennial flower strips in agricultural landscapes (Bachelor- and/or Master thesis)

  • Timeframe: Fieldwork: June – August (4 full days in total), Data processing and analysis is decoupled from fieldwork and can be done later.
  • Study sites: 6 plots with different flower strips in the region of Ammerland and Hude (near Oldenburg). Driving there by car, ideally together with other students, is required. If possible, an institute car will be provided. Due to the current Corona situation, the ability to use a private car is beneficial. Travel expenses would be covered.
  • Fieldwork extent: A total of 4 fieldwork days at intervals of 2-3 weeks between June and August. Flower visiting insects are documented during standardised transect walks and identified on the spot or, if not possible, fixed for further identification in the laboratory.
  • Reference Collection: of insect species that are not easy to identify on the spot is to be created.
  • Data processing: Counting and identification of flower visiting insects.
  • Statistical Analysis: Calculate rarefied species richness and instructed implementation of network analysis using the software R.

Contact: Swantje Grabener: swantje.grabener@leuphana.de