Searching for an ecological baseline: Long-term ecology of a post-extraction restored bog in Northern Estonia.

The exploitation of peatlands in Estonia, which began in the 17th century, has degraded them to a great extent. Consequently, cutover and drained peatlands have become the sources of CO 2. Global warming has led to a need for policies focusing on the protection and restoration of drained and degraded peatlands. Hence, to compare the effect/progress of restoration with the past pristine ecosystem baseline before the peatland was destroyed by cutting, we examined a peat core from North Estonia using chronology based on 14C by analyzing several proxies in high resolution including testate amoebae, plant macrofossils, pollen, non-pollen palynomorphs, and diatoms. The results revealed a striking ecological contrast between the pristine (ca. 2 kyrs) and restored state (currently) of the peatland. The pristine state was characterized by a domination of Sphagnum fuscum / rubellum and Archerella flavum , suggesting that extraction area of Hara peatland was a wet and stable ombrotrophic bog. As a result of peat exploitation, deposits comprising the last ca. 2 kyrs were cut. In turn an important feature of the restored section of the peat core was the domination of a green algae (Chlorophyta) and Eriophorum vaginatum as well as testate amoebae species Arcella discoides , which is considered an indicator of hydrological instability. The main difference between the predisturbed and restored parts of the peat core section was that a minor cover of peat-forming Sphagnum and mixotrophic testate amoebae was present in the top inundated part. We state that a healthy raised bog—the target of restoration—should consist abundant mixotrophic testate amoebae such as Archerella flavum and Hyalosphenia papilio which are good indicators of a well-functioning Sphagnum bog ecosystem even if the Sphagnum species differ from the reconstructed ecological baseline conditions. Our study highlights the extensive damage caused to the peat-forming ombrotrophic peatland by extraction and how difficult, challenging, and time-consuming is the process of ecological restoration. [ABSTRACT FROM AUTHOR]