The moss microbiome as mediator of forest nitrogen and carbon cycling

The future C sequestration potential of the boreal zone is tightly linked to N availability as production in these ecosystems is chronically N limited. The main source of new N is through N2-fixation, mainly from microbial communities associated with mosses.

Moss and microbiome therefore play a key, but poorly understood, role in integrating above- and belowground processes.

Knowledge about moss microbial communities involved in transformations of inorganic N species that affect the fate of the fixed N in the system has not been studied.

Specifically, the links between N-fixing communities, overall N cycling communities and the soil fungal community in the soil below need to be assessed. How newly fixed N is transferred to plants is not clear, but fungi are proposed to be involved.

The aim is to understand microbial mediated biochemical process in boreal forests and thereby determine drivers of N availability and C sequestration.

We will: 1) integrate functional (protein encoding) gene composition with N -fixation measurements; 2) identify additional N cycle pathways in the moss microbial communities; 3) determine how moss-associated fungi compare to the soil community in composition and function; and 4) study how newly fixed N is transferred to plants.

This is done in three work packages, where we combine field based methods along environmental gradients and experimental microcosm studies, with state-of-the-art techniques (next gen sequencing, qPCR and stable isotopes).