Research interests

My main interest is the trophic ecology of forest soil animals. I aim at uncovering nutrient and energy fluxes in forest soil animal food webs, thereby separating basal resources and determining trophic positions.

Food webs in soil differ fundamentally from those aboveground. They are not only based on living plants, but additionally rely on inputs from detritus, which is a complex mixture of fungi, bacteria and dead plant remains. Since soil animal food webs are hidden from direct observation and the separation of basal resources is notoriously difficult, one has to rely on indirect methods to gain insights into their structure and functioning.

My recent work focuses on compound-specific isotope analyses (CSIA) of amino acids which are increasingly used to explore complex food webs. I combine the analyses of both δ¹³C and δ¹⁵N signatures in amino acids to disentangle relative contributions of basal resources, such as bacteria, fungi and plants, to animal nutrition and to estimate trophic positions within food webs. To adapt the method for soil animal food webs, I conducted feeding trials by constructing trophic chains including bacteria, plants and fungi as basal resources, springtails and oribatid mites as primary consumers, and spiders and gamasid mites as predators (Pollierer et al. 2019).

In addition, I utilize fatty acid analyses of phospholipids (PLFAs) to characterize microbial communities in litter and soil, and of neutral lipids (NLFAs) in animals to infer basal resources using biomarker fatty acids.

I have also been using bulk stable isotope analyses (C and N) to investigate trophic structures of food webs.

Currently, I am financed by the DFG within the project “Biodiversity Exploratories”.

Former research

In the framework of the Biodiversity Exploratories (http://www.biodiversity-exploratories.de/projekte/aktuelle-projekte/tiere/litterlinks/) I investigated changes in structure and trophic ecology of forest soil animal food webs along a land use-gradient across different regions in Germany.

In the Swiss Canopy Crane Project (http://plantecology.unibas.ch/scc/index.shtml) I used compound-specific 13C stable isotope analysis of fatty acids and bulk isotopic analyses of soil animals to separate differently labelled basal resources such as leaf litter and roots and to clarify relative fluxes of carbon to the soil animal food web.