Testate Amoeba Community Response and Vegetation Composition after Plantation Removal on a Former Raised Bog

Extensive drainage of peatlands in north-west Europe for the purposes of afforestation for timber production and harvesting has altered the carbon balance and biodiversity value. Large-scale restoration projects aim to reinstate hydrological conditions to keep carbon locked up in the peat and to restart active peat growth. Testate amoebae are an informal grouping of well-studied protists in peatland environments and as microbial consumers play an important role in nutrient and carbon cycling. This study investigated the response of Testate amoeba communities and vegetation composition after tree removal on a drained raised bog. There was a clear difference in microbial communities between open and a chronosequence of restoration areas. Results suggest microbial recovery after rewetting is a slow process with the plant community showing a faster response than the microbial community. Mixotrophic testate amoebae had not recovered seventeen years following plantation removal and the establishment of Sphagnum mosses in the wetter microforms. These results suggest that vegetation composition and Testate amoeba communities respond differently to environmental drivers at forest-to-bog restoration areas. Local physicochemical peat properties were a stronger driver of the testate community compared with vegetation. Complete recovery of the microbial community may take place over decadal timescales.