Ecological succession of soil microbial communities in landslide chronosequences in New Zealand’s Southern Alps

• Applicant: Dr. Olivia Rasigraf
• Subject Area: Microbial Ecology and Applied Microbiology ; Soil Sciences ; Ecology of Land Use
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 458141274

New Zealand's Southern Alps offer an ideal environment for studying soil development in landslides due to high frequency of events, accessibility and previous extensive research, and where dating and chronosequences were already partially established. The overall aim of the proposed project is to study ecosystem restoration with a focus on microbial processes in soil. Soil microbial communities and their function will be studied in combination with geochemical and geomorphological analysis. Microbial communities and their potential functions at different stages of the chronosequence will be identified and core communities will be characterized. The identification of potential functions will be performed with primer-specific functional gene amplification and metagenomics. The obtained data will reveal how core prokaryotic (bacteria; archaea) and eukaryotic (algae; fungi) microbial community composition changes during soil succession, what functional potentials predominate at each stage and how the composition of microbial community and geochemistry influence net respiration gas fluxes in comparison to a surrounding steady state climax ecosystem. This research will lead to a better understanding of soil development processes in an ecosystem frequently disturbed by rapid mass movements and of the role of microorganisms in the development of early habitats. The identification of key taxa and dominant functions at different stages of the chronosequence has a potential to offer an additional method for future detection of ecosystem successional status. The proposed research will combine bottom up and top down approach for ecological research where the potential function of microbial communities based on their molecular identity and functional gene inventory will be complemented with field measurements of net gas fluxes and physiology studies.The research project will focus on the following questions:(a) Do landslide soils harbor distinct core communities along the chronosequence and do particular species dominate?(b) How do fluxes of key respiration gases change during succession and how do they correlate with functional gene inventory and microbial community composition?(c) How does the reactive nitrogen content (e.g. ammonium) influence the community composition of nitrifying microorganisms?Innovation- This project will elucidate primary succession from the perspective of microbial communities and their functions. The study will combine prokaryotic and eukaryotic microbial community analysis.- Soil development in landslides will be studied in a holistic approach by implementing molecular techniques combined with geochemistry and field measurements of net greenhouse gas fluxes.- Organisms involved in nitrification, a key process in the biogeochemical N cycle, will be enriched, their physiology characterized and genomes will be assembled to aid deeper understanding of their ecosystem function.

• DFG Programme: Research Grants