Biogeosciences, 14, 2571-2596, 2017
https://doi.org/10.5194/bg-14-2571-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
19 May 2017
Modelling Holocene peatland dynamics with an individual-based dynamic vegetation model
Nitin Chaudhary, Paul A. Miller, and Benjamin Smith Department of Physical Geography and Ecosystem Science, Lund University, Sölvegatan 12, 22362 Lund, Sweden
Abstract. Dynamic global vegetation models (DGVMs) are designed for the study of past, present and future vegetation patterns together with associated biogeochemical cycles and climate feedbacks. However, most DGVMs do not yet have detailed representations of permafrost and non-permafrost peatlands, which are an important store of carbon, particularly at high latitudes. We demonstrate a new implementation of peatland dynamics in a customized Arctic version of the LPJ-GUESS DGVM, simulating the long-term evolution of selected northern peatland ecosystems and assessing the effect of changing climate on peatland carbon balance. Our approach employs a dynamic multi-layer soil with representation of freeze–thaw processes and litter inputs from a dynamically varying mixture of the main peatland plant functional types: mosses, shrubs and graminoids. The model was calibrated and tested for a sub-Arctic mire in Stordalen, Sweden, and validated at a temperate bog site in Mer Bleue, Canada. A regional evaluation of simulated carbon fluxes, hydrology and vegetation dynamics encompassed additional locations spread across Scandinavia. Simulated peat accumulation was found to be generally consistent with published data and the model was able to capture reported long-term vegetation dynamics, water table position and carbon fluxes. A series of sensitivity experiments were carried out to investigate the vulnerability of high-latitude peatlands to climate change. We found that the Stordalen mire may be expected to sequester more carbon in the first half of the 21st century due to milder and wetter climate conditions, a longer growing season, and the CO2 fertilization effect, turning into a carbon source after mid-century because of higher decomposition rates in response to warming soils.

Citation: Chaudhary, N., Miller, P. A., and Smith, B.: Modelling Holocene peatland dynamics with an individual-based dynamic vegetation model, Biogeosciences, 14, 2571-2596, https://doi.org/10.5194/bg-14-2571-2017, 2017.
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We incorporated peatland dynamics into Arctic version of dynamic vegetation model LPJ-GUESS to understand the long-term evolution of northern peatlands and effects of climate change on peatland carbon balance. We found that the Stordalen mire may be expected to sequester more carbon before 2050 due to milder and wetter climate conditions, a longer growing season and CO2 fertilization effect, turning into a C source after 2050 because of higher decomposition rates in response to warming soils.
We incorporated peatland dynamics into Arctic version of dynamic vegetation model LPJ-GUESS to...
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