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The influence of climate on peatland extent in Western Siberia since the Last Glacial Maximum.

Alexandrov GA, Brovkin VA, Kleinen T - Sci Rep (2016)

Bottom Line: Boreal and subarctic peatlands are an important dynamical component of the earth system.They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source.Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task.

View Article: PubMed Central - PubMed

Affiliation: A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Pyzhevsky 3, Moscow, 119017, Russia.

ABSTRACT
Boreal and subarctic peatlands are an important dynamical component of the earth system. They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source. Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task. Here we introduce a climatic index, warm precipitation excess, to delineate the potential geographic distribution of boreal peatlands for a given climate and landscape morphology. This allows us to explain the present-day distribution of peatlands in Western Siberia, their absence during the Last Glacial Maximum, their expansion during the mid-Holocene, and to form a working hypothesis about the trend to peatland degradation in the southern taiga belt of Western Siberia under an RCP 8.5 scenario for the projected climate in year 2100.

No MeSH data available.


Related in: MedlinePlus

The fraction of land that could be occupied by peatlands under present climate (upper left corner), mid-Holocene climate (lower left corner), and climate in 2100 following the RCP 8.5 scenario (upper right corner), and for a given value of WPE (lower right corner), when P/PET = 1.2, and the length of the warm period is 5 months.The dashed orange line encircles the area within the Tobol river basin where fP simulated for mid-Holocene climate exceeds the present level. The fraction of land that could be occupied by peatlands under LGM climate is not shown, because it has spatially uniform value that equals zero. Made with MapWindow 4.8.8 (http://www.mapwindow.org/), Natural Earth public domain map data (http://www.naturalearthdata.com/about/terms-of-use/), and map colors from www.ColorBrewer.org.
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f2: The fraction of land that could be occupied by peatlands under present climate (upper left corner), mid-Holocene climate (lower left corner), and climate in 2100 following the RCP 8.5 scenario (upper right corner), and for a given value of WPE (lower right corner), when P/PET = 1.2, and the length of the warm period is 5 months.The dashed orange line encircles the area within the Tobol river basin where fP simulated for mid-Holocene climate exceeds the present level. The fraction of land that could be occupied by peatlands under LGM climate is not shown, because it has spatially uniform value that equals zero. Made with MapWindow 4.8.8 (http://www.mapwindow.org/), Natural Earth public domain map data (http://www.naturalearthdata.com/about/terms-of-use/), and map colors from www.ColorBrewer.org.

Mentions: The impeded drainage model (IDM) implies that the critical threshold of WPE, beyond which the expansion of peatlands is started, increases with the averaged watershed elevation above the level of the drainage system, g. The higher is g, the higher is the threshold. We estimated its values for grid cells of MPI-ESM from the present geographic distribution of peatlands (ref. 17). Optimized g values, that is, the values that make IDM fit data on the fraction of land covered by peatlands, vary between 2.6 and 19.6 m, that is, around 10 m. At g = 10 m, half of the watershed area is suitable for peatland expansion when WPE is equal to 30 mm/yr (Fig. 2, lower right corner). Therefore, 30 mm/yr could be considered a level of WPE that “turns on” the process of massive peatland expansion in Western Siberia. This is, of course, a very coarse estimate. It does not take into account the spatial diversity of climatic conditions, and therefore, its use is limited to continental scale, e.g., for delineating climatic regions where peatlands may theoretically occur.


The influence of climate on peatland extent in Western Siberia since the Last Glacial Maximum.

Alexandrov GA, Brovkin VA, Kleinen T - Sci Rep (2016)

The fraction of land that could be occupied by peatlands under present climate (upper left corner), mid-Holocene climate (lower left corner), and climate in 2100 following the RCP 8.5 scenario (upper right corner), and for a given value of WPE (lower right corner), when P/PET = 1.2, and the length of the warm period is 5 months.The dashed orange line encircles the area within the Tobol river basin where fP simulated for mid-Holocene climate exceeds the present level. The fraction of land that could be occupied by peatlands under LGM climate is not shown, because it has spatially uniform value that equals zero. Made with MapWindow 4.8.8 (http://www.mapwindow.org/), Natural Earth public domain map data (http://www.naturalearthdata.com/about/terms-of-use/), and map colors from www.ColorBrewer.org.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837369&req=5

f2: The fraction of land that could be occupied by peatlands under present climate (upper left corner), mid-Holocene climate (lower left corner), and climate in 2100 following the RCP 8.5 scenario (upper right corner), and for a given value of WPE (lower right corner), when P/PET = 1.2, and the length of the warm period is 5 months.The dashed orange line encircles the area within the Tobol river basin where fP simulated for mid-Holocene climate exceeds the present level. The fraction of land that could be occupied by peatlands under LGM climate is not shown, because it has spatially uniform value that equals zero. Made with MapWindow 4.8.8 (http://www.mapwindow.org/), Natural Earth public domain map data (http://www.naturalearthdata.com/about/terms-of-use/), and map colors from www.ColorBrewer.org.
Mentions: The impeded drainage model (IDM) implies that the critical threshold of WPE, beyond which the expansion of peatlands is started, increases with the averaged watershed elevation above the level of the drainage system, g. The higher is g, the higher is the threshold. We estimated its values for grid cells of MPI-ESM from the present geographic distribution of peatlands (ref. 17). Optimized g values, that is, the values that make IDM fit data on the fraction of land covered by peatlands, vary between 2.6 and 19.6 m, that is, around 10 m. At g = 10 m, half of the watershed area is suitable for peatland expansion when WPE is equal to 30 mm/yr (Fig. 2, lower right corner). Therefore, 30 mm/yr could be considered a level of WPE that “turns on” the process of massive peatland expansion in Western Siberia. This is, of course, a very coarse estimate. It does not take into account the spatial diversity of climatic conditions, and therefore, its use is limited to continental scale, e.g., for delineating climatic regions where peatlands may theoretically occur.

Bottom Line: Boreal and subarctic peatlands are an important dynamical component of the earth system.They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source.Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task.

View Article: PubMed Central - PubMed

Affiliation: A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Pyzhevsky 3, Moscow, 119017, Russia.

ABSTRACT
Boreal and subarctic peatlands are an important dynamical component of the earth system. They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source. Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task. Here we introduce a climatic index, warm precipitation excess, to delineate the potential geographic distribution of boreal peatlands for a given climate and landscape morphology. This allows us to explain the present-day distribution of peatlands in Western Siberia, their absence during the Last Glacial Maximum, their expansion during the mid-Holocene, and to form a working hypothesis about the trend to peatland degradation in the southern taiga belt of Western Siberia under an RCP 8.5 scenario for the projected climate in year 2100.

No MeSH data available.


Related in: MedlinePlus