Quantifying nitrogen fixation by moss-cyanobacteria associations from community to global scale by developing a novel process-based modelling approach

Nitrogen (N) fixation by moss-cyanobacteria associations is crucial for N input and productivity in pristine ecosystems. Despite its importance, substantial knowledge gaps exist. Current regional and global estimates of moss-associated N2 fixation are uncertain due to limited sampling and species coverage, leaving the global pattern of moss-associated N2 fixation unresolved. Additionally, the mechanisms driving large variation in N2 fixation across different moss species remain unraveled. This project aims to address the critical knowledge gaps by (1) collecting comprehensive data on N2 fixation from moss-cyanobacteria associations across climate zones under controlled abiotic factors; (2) quantifying the relationship between N2 fixation and abiotic factors in different climate zones; (3) developing a process-based model (LiBry-CyBac) that includes N2 fixation to quantify the impact of the interactions between cyanobacteria and moss on variation in N2 fixation across moss species; (4) applying this model to identify global moss-associated N2 fixation pattern and its implication for ecosystem productivity.Combining my expertise in moss modelling with the host’s expertise in moss-cyanobacteria N2 fixation, this project takes an interdisciplinary approach involving biogeochemistry, ecophysiology, and symbiosis research. The expected high-quality publications, training in experimental design, laboratory measurements and analyses such as gas chromatography, model development, and other professional skills (e.g., grant application writing, student supervision, teaching, and project management) will greatly benefit my career development. The effective dissemination of research results will enhance public awareness of important moss functions (i.e., N2 fixation) and the impact of abiotic factors like warming, promoting public support for the European Commission's climate neutrality goals for 2050 and guiding policymakers on effective management and conservation strategies