Pollen and non-pollen palynomorphs as tools for identifying alder carr deposits: A surface sample study from NE-Germany

Alder wood peat is regularly found in central Europe, but palaeoecological studies of alder wood peat are rare, mainly because of lack of identifiable pollen and macrofossils. One central question is whether alder wood peat accumulates under alder carr vegetation (primary) or as displacement peat with alder roots growing into existing peat formed under open fen vegetation (secondary). Standard palaeoecological methods have proven unsuited to solve this question. This paper presents a surface sample study testing whether non-pollen palynomorphs (NPPs) can be used for identifying various types of fen vegetation, especially alder carrs, and for reconstructing the formation of wood peat. Different substrate types (litter, moss, dead wood, water and exposed peat surface) were sampled in 10 alder carrs, one birch cart and three sites with open fen vegetation in NE-Germany and analysed for pollen and NPPs. Vegetation relevees were recorded and water and soil conditions were measured. We overall recorded 412 NPP types, including 36 known EMA types (recorded in alder carr) and 51 HDV types (recorded in other ecosystems). For present publication we selected the 96 most abundant and characteristic NPPs (including 14 HDV types and 36 known EMA types). 46 NPP types are newly described and illustrated. Our study shows that, opposed to pollen, NPP types clearly reflect the different fen vegetation types making NPPs a valuable tool in palaeoecological studies of fen peat. (C) 2012 Elsevier B.V. All rights reserved.