Associated Projects

Metabolite Changes in Biodiversity Levels and Seasonal Shifts (MacBeSSt)

Principle Investigators: Dr. Steffen Neuman, Halle; Dierk Scheel, Prof. Dr. Helge Bruelheide, Halle; Kristian Peters; Prof. Nicole van Dam, Jena
PhD student: Susanne Marr

The MacBeSSt project focuses on combining different experimental and analytical methods to investigate metabolomic changes within and between plant species grown in the Jena Experiment.
Liquid Chromatography, coupled with Mass Spectrometry, along with automated processing methods, are used as analytical tools for ‘metabolite fingerprint’ investigations in herb and grass species that grew in different plant communities and biodiversity levels. The vegetative aboveground biomass was sampled at four time-points across the growing season May to October.
By determining biochemical patterns and trait relationships between plant species, species communities and the environment, this project aims to build a bridge between the research areas ecology, biochemistry and bioinformatics.

How does biodiversity loss affect the response of plant species to global change?

Principle Investigators: Christiane Roscher, Nico Eisenhauer, Simone Cesarz
PhD student: Peter Dietrich

Loss of diversity can alter the selection environment that plants experience, so that persisting species must adapt to novel biotic interactions, especially to changes in the composition of mutualistic and antagonistic soil biota (new positive or negative plant-soil feedbacks). However, little is known about how fast the remaining species adapt to the novel biotic conditions and whether such micro-evolutionary processes affect the response of these species to global change. To address this knowledge gap, we investigated species-poor and species-rich plant communities and performed a common garden and a phytometer experiment to test the following hypotheses:

(1) Species interactions with soil biota depend on their shared plant diversity and environmental histories (1a), such that species are better adapted to their soil environment of origin (home-soil). Species performance is weaker if individuals are transplanted into a different soil environment (away-soil; 1b).
(2) Plant individuals in their origin soil environment (home-soil) have a higher performance than individuals transplanted into a different soil environment (away-soil), when treated with global change drivers (drought, increased nitrogen input).
To test hypothesis 1a, we took plant and soil samples to determine species performance (plant biomass, root biomass, nitrogen concentrations in plant and soil, etc.) and the degree of negative and positive plant-soil feedbacks (nematodes, mycorrhizal colonization) in the 1-, 2-, 6- and 9-species plots of the dominance experiment. Furthermore, in 2018 we established the phytometer experiment to check hypothesis 1b. Therefore, we collected seeds from 4 grass species growing in the 2- and 6-species plots of the dominance experiment and transplanted seedlings grown from these seeds either in the dominance plot where the mother was growing (home-soil) or in plots with a different soil environment (away-soil; after removal of the vegetation). To test hypothesis 2, we took soil and seed samples from the same dominance plots, which were also used for the phytometer experiment, and established a common garden experiment manipulating the soil environment (home or away) and the impact of drought and increased nitrogen input in a full factorial design.

We expect that species-rich communities show more positive plant-soil feedbacks and species-poor communities more negative plant-soil feedbacks. Furthermore, we expect that individuals in home-soil show higher performance (biomass) and higher resistance to global change drivers than individuals in away-soil. These results could help to prove whether plant individuals of the same species took different evolutionary pathways depending on the plant species diversity of neighborhood and resulting specificity of soil biota and that micro-evolutionary changes may impact species responses to global change drivers, which might be important to understand the mechanisms how ecosystems respond to the ongoing process of global change.

Plant chemistry-mediated effects of above- and belowground biodiversity on herbivory

Principle Investigators: Prof. Dr. Nicole M. van Dam, Jena; Prof. Dr. Nico Eisenhauer, Leipzig; Dr. Alexander Weinhold, Jena
PhD student: Christian Ristok

This project aims to integrate eco-metabolomics and biodiversity-ecosystem functioning (BEF) experiments to enhance our knowledge about multitrophic interaction in natural ecosystems. We analyze and experimentally manipulate interactions between plants and their above- and belowground interaction partners. In more detail, we 1) study how plant diversity-driven shifts in soil biota elicit changes in the composition and diversity of shoot and root secondary metabolites; 2) study the simultaneous effect of aboveground and belowground biodiversity on plant metabolomes of common grassland species in the Jena Experiment; and 3) separately analyze the importance of aboveground biodiversity, i.e. plant-plant interaction, versus belowground biodiversity, i.e. soil biota-plant interaction, on the chemical diversity within a plant. As part of each aspect, we further test how the induced changes in the secondary metabolites affect herbivory/herbivore resistance. Eventually this new knowledge will help us to improve our predictions on changes in plants, communities and multitrophic interactions, and to assess the impact of biodiversity loss through changes in the plant metabolome.

Drivers of Ecosystem Services in Heterogeneous Landscapes (ECOSERV)

Principle Investigators: Jean Paul Metzger, Prof. W. Weisser and Dr. Sebastian T. Meyer
PhD student: Laura Argens

The ECOSERV project researches the impact of different drivers on the provision of ecosystem services in grasslands. An ecological synthesis should clarify the wide variety of responses considering how land use/ land cover, biodiversity or climate affect ecosystem service provisioning. Researchers proposed to use data from the Jena Experiment for studying long-term effects on the relationships between Ecosystem functions. As a first project, the variability of trade-offs between Ecosystem Functions depending on the number of data points included in the analysis based on the measurements done in Jena will be evaluated.

Associated project with Aaron Fox

Optimal management of grasslands is a key strategy towards their agronomic and environmental sustainability, helping to meet an ever-increasing demand for food. Central to achieving this is a greater insight into the functional relationship between the plant and the plethora of microorganisms that are associated with its roots: the microbiome. A critical knowledge gap is the consequence of varying plant and microbial diversity on the soil nutrient turnover of two macronutrients: nitrogen (N) and phosphorus (P), both essential for plant growth. I will take a two-step approach to addressing this question. Firstly, I will investigate how altering plant diversity (i.e., monocultures vs high diversity swards, as well as the  presence/absence/proportion of N-fixing legumes) influences how the microbiome breaks-down complex nutrient forms of N and P for plants to assimilate. To answer this question, I will do metagenomic analysis on samples from the renowned Jena biodiversity experiment, as well as establish mesocosm systems in which I vary the proportion of legumes in non-legume/legume mixtures. In the second step, I will view the question from the opposite direction. Here I will study the differences in how high vs. low soil microbial diversity make N and P plant-available and how such distinctions impact the growth performance of a plant and its consequential response to environmental stress, using diversity manipulation experiments on the soil microbiome. The findings of this project will emphasize to farmers the importance of maintaining above- and belowground biodiversity for the sustainability of grassland production systems. The project has received funding from the RL2025 fellowship scheme, co-funded by Teagasc (the Irish agricultural research authority) and the Marie Skłodowska-Curie scheme of the EU.