The influence of paludiculture intensity on peat microbial community composition and resulting greenhouse gas emissions from fen peatlands

Microbial communities play a critical role in peatland ecosystems, and in determining whether they act as net sinks or sources of greenhouse gas (GHG) emissions to the atmosphere. Furthermore, microbial community composition responds to changes in water table and physicochemical conditions, which are also determinants of GHG emissions from peatlands. Land management practices can significantly impact the water table and soil physicochemical conditions, influencing soil microbial community composition and activity, and site specific GHG emissions. Our study aimed to elucidate the role of paludiculture (peat conserving land use) intensity and nitrogen concentration on microbial community composition and function, and in turn, the potential role of changing microbial communities on seasonal GHG emission dynamics. We investigated GHG emissions, as well as a range of site physicochemical parameters, from 14 different EU fen peatlands, located in Germany (6), Netherlands (4) and Poland (4), on a monthly basis over the course of two years. Additionally, seasonal peat samples over two depths (living surface or 0cm, and at ~ 15cm depth below surface) were analysed for microbial community composition and function. Sample sites were separated into two different categories: Typha sp. dominated sites (7 sites, assumed to be highly nitrogen contaminated) and Carex sp. dominated (7 sites, assumed to be moderately Nitrogen contaminated) sites, with each further separated into three different paludiculture intensities: Wet wilderness (6 sites), Low intensity Paludiculture (6 sites) and High intensity paludiculture (2 sites). Initial results suggest a close relationship between microbial community composition and the sample country, as well as hydrological and nutrient status of the site, with a potentially significant relationship between microbial community composition, their main functions, and specific GHG emissions. The findings of our study would help to better understand how different paludiculture practices may impact microbial communities and influence GHG emissions from differently managed paludiculture sites.