 |
| Titel |
Physical and chemical differences between natural and artificial pools in blanket peatlands |
| VerfasserIn |
Ed Turner, Andy Baird, Mike Billett, Pippa Chapman, Kerry Dinsmore, Joseph Holden |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092896
|
| Publikation (Nr.) |
 EGU/EGU2014-7261.pdf |
|
|
|
|
|
| Zusammenfassung |
| Natural pools are common features of many northern peatlands. Numerous artificial pools are
being created behind dams installed during drain-blocking, a common peatland restoration
technique, significantly increasing the area of open water. Natural pools are known to be
major sources of GHGs (e.g. Hamilton et al. 1994), but the reasons they are such ‘hotspots’ is
poorly understood. We hypothesize that pools act as ‘biochemical reactors’ of particulate and
dissolved organic carbon (POC and DOC) transported from surrounding peat that is
processed into a range of products including CH4 and CO2. Therefore, understanding the
processes operating in both natural and artificial pool systems is fundamental to elucidating
this hypothesis.
Water levels and temperature have been continuously monitored at six natural and six
artificial pools within the ‘Flow Country’ blanket peatland in northern Scotland since May
2013. Bi-weekly sampling of waters from pools, peat matrix through-flow (via piezometers)
and surface flow has been conducted for analysis of DOC, POC, DIC, CH4diss and
CO2diss, together with GHG flux measurements from pool surfaces and adjacent
peat.
We show that, to date, pool water levels rapidly respond to rainfall, although artificial pools
appear to respond with greater magnitude. For example, over the course of same rainfall event
(20-23 June 2013), natural and artificial pool levels increased between 5.3 and 9.8 cm, and
12.5 and 22.6 cm respectively. Temperature measured at c. 5 cm from the base of each pool
shows distinct diurnal fluctuations, which are of greater magnitude in all but one of the
natural pools compared to the artificial pools: over the same period (20-23 July 2013),
the maximum diurnal variation at the artificial pool site was 5.1 °C compared to
9.2 °C within the natural pools. Vegetation cover is generally higher in artificial
pools and may have a moderating effect on variations in pool temperature. Results
of pool-water DOC analysis from regular sampling at the study site and a wider
regional survey indicate DOC concentrations are consistently higher in artificial
pools.
The implications of these preliminary results in relation to the carbon cycle and GHGs of
blanket peatlands are briefly discussed.
Hamilton, J. D., Kelly, C. A., Rudd, J. W. M., Hesslein, R. H. and Roulet, N. T. (1994) Flux
to the atmosphere of CH4 and CO2 from wetland ponds on the Hudson Bay lowlands
(HBLs). Journal of Geophysical Research 99, 1495-1510. |
|
|
|
|
|
|