Testate amoeba as a palaeohydrological indicator in mountain peatlands in the south of Norway

The use of testate amoeba as a palaeohydrological indicator in Norwegian wetlands is very limited and mainly focused on salt marshes with non-existent studies in this field in boreal, Atlantic, and mountain peatlands. This study could be the basis for additional future work on understanding past hydrological dynamics in Norwegian mountain peatlands by qualitatively or quantitatively approaches of reconstruction. The study areas included: 1) a more ombrotrophic bog located in Upsete at around 800 m.a.s.l facing a more Atlantic climate and near the treeline, and 2) a poor fen in Øynan, located at a higher elevation site (1100 m.a.s.l) in the low alpine region with a more continental climate in the southern mountain area of the country. To isolate the testate amoebas, we followed a water-based method and under the microscope, we counted a minimum of 150 testates in around 30 samples per peat profile for each of the two sites. Among the species of Testate amoebae that indicated wetter conditions, we found Archerella flavum, Centropyxis discoides, Hyalosphenia papillo and Heleopera petricola as the most representatives. There are two marked periods at Upsete, where wetter indicator species appear: between 9500 and 10500 yrs BP and between 3000 and 4500 BP. Similarly, at the Øynan site, the periods that indicated wetter conditions correspond to 8000 – 9000 yrs BP and 3500 – 5000 yrs BP. At the same time, the wetter periods indicated by testate amoebae analyses also match the periods of higher carbon accumulation that was also recorded in the laboratory.