Project description
Forest diversity can increase productivity, but current research on underlying mechanisms, including implications for drought resilience, predominantly relies on aboveground measurements. This limits our knowledge of belowground complementarity in terms of resources use. The main objective of this project is to develop an understanding of the underlying factors leading to the recently observed relationship between root water uptake and neighbourhood tree diversity in a beech-dominated unmanaged forest in 2019 (part of AquaDiva, Hainich National Forest, for details see Demir et al. (2023)). The hypothesis that enhanced water uptake in species-rich neighbourhoods is associated with improved resource use due to an increased belowground complementarity will be tested. For this purpose, the candidate will take advantage of the established dense soil moisture sensing network at the site which provides high temporal and spatial resolution measurements since 2015. Bi-annual forest inventories and local meteorological data are also available. This unprecedent dataset will be used for an in-depth analysis of temporal and spatial changes in root water uptake. Furthermore, the available measurements at the site, will be complemented with the exploration of key ecosystem properties related to resource availability and tree uptake capacity that will be measured in tree neighbourhoods with different species richness. Thereby, the candidate will conduct field work to assess seasonal changes of:
- plant available nitrogen and phosphorous
- tree root traits related to soil resource scavenging
- colonization rates of tree roots by mycorrhizal fungi
- measurements of plant transpiration
- functional richness of the understory vegetation
These findings may furthermore be compared to measurements from other forest sites having different soil moisture and physical properties.
Working group & planned collaborations
The PhD candidate will work in the Terrestrial Ecohydrology group of Anke Hildebrandt at FSU Jena who will be the main advisor of this project, in close collaboration with the MPI-bgc Processes Department (Marion Schrumpf, who will advise the project with her expertise on soil processes), the Helmholtz Centre for Environmental Research -UFZ (Emily Solly and Mika Tarkka who will respectively contribute to the project with expertise of root and mycorrhizal symbiosis assessments) and the Plant Biodiversity group at FSU Jena of Christine Römermann (who will advise the project with her expertise in plant ecology and for the assessment of understory functional diversity). There will be opportunities for further collaborations at the MPI-bgc institute, the German Centre for integrative Biodiversity research Halle, Jena Leipzig (iDiv) as well as to join existing collaborations in other institutions in Germany and abroad.
Requirements
Applications to the IMPRS-gBGC are open to well-motivated and highly-qualified students from all countries. Prerequisites for the proposed PhD project are:
- a MSc degree in soil science, ecology, biogeochemistry, biology or other disciplines related to environmental sciences
- Advanced knowledge of at least one of the following fields: terrestrial ecosystem ecology, soil science, plant biology, or biogeochemistry.
- basic expertise in statistical modeling, interest in process-based models
- interest in doing field and laboratory work
- interest in interactions between plants and soils
- Excellent oral and written communication skills in English written, knowledge if German is an asset
The Max Planck Society (MPS) strives for gender equality and diversity. The MPS aims to increase the proportion of women in areas where they are underrepresented. Women are therefore explicitly encouraged to apply. We welcome applications from all fields. The Max Planck Society has set itself the goal of employing more severely disabled people. Applications from severely disabled persons are expressly encouraged.
Reference
Demir, G., A. J. Guswa, J. Filipzik, J. C. Metzger, C. Römermann, and A. Hildebrandt. 2023. Root water uptake patterns are controlled by tree species interactions and soil water variability. Hydrol. Earth Syst. Sci. Discuss. 2023:1-41. https://doi.org/10.5194/hess-2023-91
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