Expanding NPP analysis to eutrophic and forested sites: Significance of NPPs in a Holocene wood peat section (NE Germany)

Alnus glutinosa-dominated peatlands are widespread in central Europe, but the generally bad preservation of micro- and macrofossils has hampered palaeoecological research of their peats. Because of its large carbon sequestration rate, however, peat accumulation in forested peatlands is of special interest for climate change research. This study identifies indicator groups for various types of alder (A. glutinosa) carr and sedge (Carex) fen vegetation, elaborated by analysis of non-pollen palynomorphs (NPPs) from peat and surface samples. The indicator value of fungal spores and decomposition products of wood was tested by correlation with pollen (especially alnus) and macrofossils. Only few indicators of alder carr also occurred with low and constant values during distinct open sedge fen phases, which indicates that small and plane shaped NPPs can be dispersed extra-locally. The diversity and abundance of NPPs appeared to depend on vegetation type and resulting nutrient supply and to water regime and resulting decomposition intensity during peat development.

► We expand the approach of NPP analysis to eutrophic and forested sites.
► We prove the usefulness of EMA-types from fen surface samples in wood peat sections.
► We include knowledge from mycology to improve interpretation of NPP data.
► We prove that NPPs can have an extralocal origin.
► We conclude that site conditions greatly affected abundance of NPPs.