Impact of long-term wetting on carbon cycling and climate change feedback in a northern temperate bog (Ontario, Canada)
Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
Final Report Abstract
As excessive supply of nutrients is widely known to be a threat to naturally nutrient limited peatlands, the results of this project are somewhat surprising. Despite of long-term infiltration of nutrients, the studied peatland complex did not seem to decay, instead it accelerated growth as indicated by huge peat accumulation rates and results from greenhouse gas flux measurements. On the other hand, dramatic changes of the vegetation cover as compared to the 1950s and 1980s indicated a transformation of the once ombrotrophic bog into a (poor) fen. However, by accelerating growth, the peatland may be able to outgrow the eutrophic conditions and become ombrotrophic again in the future. Moreover, certain PFTs’ role in the peatland’s obviously accelerated carbon cycling was elaborated. The presence of shrubs led to reduced recalcitrance of peat, to a more decomposed and surficial aerated peat, which suggested a higher share of CH4 oxidation. On the other hand, a graminoid-moss dominated site was a great sink of CO2, but a great source of CH4; methanotrophic activity appeared to be suppressed. These results are tying in with recent studies, dealing with the question whether increased nutrient availability may increase the CO2 uptake strength of peatlands while increasing CH4 emissions. Our results suggest that the dominance of shrubs may turn the peatland into weaker carbon sinks or even sources of carbon, while a graminoid-moss dominance may maintain the peatland’s carbon storage function – increased CH4 emissions could be outweighed by an increased CO2 uptake.
Publications
- Summer fluxes of methane and carbon dioxide from a pond and floating mat in a continental Canadian peatland. Biogeosciences 13 (2016) 3777-3791
Burger M, Berger S, Spangenberg I, Blodau C
(See online at https://doi.org/10.5194/bg-13-3777-2016) - Peatlands in a eutrophic world – assessing the state of a poor fenbog transition in southern Ontario, Canada, after long term nutrient input and altered hydrological conditions. Soil Biology & Biochemistry 114C (2017) 131-144
Berger S, Gebauer G, Blodau C, Knorr K-H.
(See online at https://doi.org/10.1016/j.soilbio.2017.07.011) - Plant functional types, nutrients and hydrology drive carbon cycling along a transect in an anthropogenically altered Canadian peatland complex. Biogeosciences Discussions 2017
Berger S, Praetzel L, Goebel M, Blodau C, Knorr K-H
