PhD Researcher (f/m/x)

The Helmholtz Centre for Environmental Research (UFZ) with its 1,100 employees has gained an excellent reputation as an international competence centre for environmental sciences. We are part of the largest scientific organisation in Germany, the Helmholtz association. Our mission: Our research seeks to find a balance between social development and the long-term protection of our natural resources.

The PhD position is part of the Research Unit PhytOakmeter. PhytOakmeter offers 10 positions for doctoral researchers, and 3 for postdoctoral researchers, addressing various aspects (i) of the phenotypic plasticity of forest trees, (ii) about the interplay of trees with their microbiome and soil nematodes, and (iii) about how these interactions may facilitate acclimation (regulatory changes) and adaptation based on genetic changes of trees and/or their holobiont partners (for more information about the Research Unit, visit https: // www. uni-marburg.de/en/fb17/phytoakmeter). Within the PhytOakmeter project, the project SP7 investigates “The role of tree-nematode interactions in the acclimation and adaptation of trees”. The health of trees, as well as their ability to adapt and acclimate (A&A) to a changing environment, is intimately linked to soil biota. While the role of soil microbes in tree health has been demonstrated across a range of species, the role of soil nematodes, which interact with both the tree and the associated microbes, has received little attention. Soil nematodes occupy all trophic levels in soil and can modulate above-belowground relationships, affecting the tree directly through feeding (i.e., plant-parasitic nematodes) and indirectly by selectively feeding on soil microbial communities (i.e., fungivorous and bacterivorous nematodes). At the same time, these interactions can affect the gene expression of plants and induce defense mechanisms (i.e., the release of root exudates and volatiles) which may alter nutrient cycles and further modulate tree health, A&A, and susceptibility to environmental stress like drought. In particular, as they inhabit soil water films, nematodes are sensitive to changes in moisture availability triggered by drought. Thus, drought can alter nematode communities and their direct and indirect influence on plant health and A&A mechanisms. This project will determine the role of soil nematode communities in modulating the A&A of drought- stressed DF159 oak clone trees and their associated microbiota. The doctoral researcher will combine taxonomic and molecular nematode monitoring approaches with soil function (substrate- induced respiration (SIR) method, phospholipid fatty acid (PLFA) analysis, and enzyme analysis) data to fine-tune techniques for nematode detection; and assess the direct and indirect effects of drought-induced alterations in soil nematode communities on tree health and A&A across a European aridity gradient and in a canopy crane experiment

Participation in the working group seminars, lab meetings, and the HIGRADE graduate school