Skip to main content


Through the interdisciplinary cooperation between atmospheric physicists (CAS-IAP), soil biogeochemists (IMK-IFU), soil scientists (TUM; CAS-IGA; University of Copenhagen), microbiologists (COMI) and plant physiologists (CMEP), the Sino-German project NIFROCLIM aims at a holistic understanding of the permafrost soil nitrogen cycle and associated N2O emissions.

Established cooperations:


Technical University Munich and the Research Unit for Comparative Microbiome Analyses at Helmholtz Zentrum München closely cooperate to develop strategies for the sustainable use of genetic resources of microorganisms to improve human, animal and plant health and to maintain soil quality and ecosystem services. Therefore, we combine high-end sequencing technologies with cultivation depending enrichment techniques, gene quantification methods, localization of microbes in their respective habitats and stable isotope probing.

As microorganisms are key drivers for nutrient turnover, understanding the structure, genetic potential and activity of the soil microbiome and how it is influenced by frequent freezing and thawing transitions in permafrost landscapes is essential to predict future N2O emissions.

In NIFROCLIM, we reconstruct microbial nitrogen (N) turnover via next generation sequencing and quantitative PCR approaches. Metagenomics are used both to describe a functional core microbiome, essential for the resilience and maintenance of soil functions, and to identify the dominant processes and microbial groups involved in N cycling. Furthermore, PacBio long read sequencing enables us to analyze complete operon structures and to identify promoters. This makes a prediction of the regulation of gene expression possible, which might be of high relevance to understand denitrification and the related N gas fluxes.

The newly established Center of Molecular Ecophysiology (CMEP) at Southwest University in Chongqing, China, aims to provide important information on the influence of global climate change on the performance of ecosystems in China and beyond. It has thus started studies supporting sustainable land-use in forestry, agriculture and agro-foresty. Therefore, research at the CMEP involves studies with Robinia, Citrus and Alnus applying ecological, physiological and molecular approaches. As root symbioses with soil microorganisms in these tree species are of high significance for restoration and de-contamination of soils, research at the CMEP addresses the interaction of trees with microbial soil communities. This research is targeted at establishing a model system to study processes and strategies of tree-microbial interactions from the molecular to the ecosystem level. Concerning biological nitrogen fixation by root symbioses, legumes are central in agriculture and tropical forests, while in remote ecosystems like permafrost areas alder trees (Alnus) might be essential. As the colleagues from CAS-IAP observed that thawing permafrost landscapes in Mohe are invaded by alder trees, the CMEP team is cooperating in the NIFROCLIM project with the following study goals:

a)     Characterizing the significance of alder tree invasion for the temperature development in thawing permafrost soils

b)     Quantifying the nitrogen fixation capacity of alder trees invading permafrost soils

c)     Characterizing the transfer of nitrogen fixed by alder trees to other dominant plant species in thawing permafrost soils

With these research activities CMEP will provide important information on ecosystem processes involved in nitrogen use and turnover in thawing permafrost soils.