Lateral expansion and carbon exchange of a boreal peatland in Finland resulting in 7000 years of positive radiative forcing

Abstract

Data on past peatland growth patterns, vegetation development, and carbon (C) dynamics during the various Holocene climate phases may help us to understand possible future climate‐peatland feedback mechanisms. In this study, we analyzed and radiocarbon dated several peat cores from Kalevansuo, a drained bog in southern Finland. We investigated peatland succession and C dynamics throughout the Holocene. These data were used to reconstruct the long‐term atmospheric radiative forcing, i.e., climate impact of the peatland since initiation. Kalevansuo peat records revealed a general development from fen to bog, typical for the southern boreal zone, but the timing of ombrotrophication varied in different parts of the peatland. Peat accumulation patterns and lateral expansion through paludification were influenced by fires and climate conditions. Long‐term C accumulation rates were overall lower than the average values found from literature. We suggest the low accumulation rates are due to repeated burning of the peat surface. Drainage for forestry resulted in a nearly complete replacement of typical bog mosses by forest species within 40 years after drainage. The radiative forcing reconstruction suggested positive values (warming) for the first ~7000 years following initiation. The change from positive to negative forcing was triggered by an expansion of bog vegetation cover and later by drainage. The strong relationship between peatland area and peat type with radiative forcing suggests a possible feedback for future changing climate, as high‐latitude peatlands may experience prominent regime shifts, such as fen to bog transitions.

Inconsistent Response of Arctic Permafrost Peatland Carbon Accumulation to Warm Climate Phases

“…Replicated records from the same peatland should provide a more robust picture of past peatland dynamics (Loisel & Garneau, ; Mathijssen et al, , ; Pelletier et al, ; Zhang et al, ). Our study supports the need for replication.…”

Recent peat and carbon accumulation following the Little Ice Age in northwestern Québec, Canada

“…To address the question how high-latitude peatland vegetation and carbon dynamics will respond and have responded to recent warming, more data are needed including highresolution chronologies and multiple cores, as presented in this study. The presented data highlight the importance of studying multiple peat sections from one study site and preferably the approach should be extended to regional-scales as stated by our third research question and the internal variability needs to be take into account when thinking about upscaling and modelling of results (Loisel and Garneau 2010, Lamarre et al 2012, Mathijssen et al 2017, Zhang et al 2018a.…”

Temporal Variation of Ecosystem Scale Methane Emission From a Boreal Fen in Relation to Temperature, Water Table Position, and Carbon Dioxide Fluxes

“…As the greenhouse gas balances, including methane emission, of northern peatlands can change either naturally (Mathijssen et al, 2016(Mathijssen et al, , 2017 or due to human intervention (Mathijssen et al, 2017;Petrescu et al, 2015), it is crucial to understand the dynamic responses of methane emission to abiotic and biotic drivers. Also, northern latitudes are expected to experience faster than average climate warming (IPCC, 2013), which makes this understanding even more important.…”