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| Titel |
Impact of fire on macropore flow and the hydraulic conductivity of near-surface blanket peat |
| VerfasserIn |
Joseph Holden, Catherine Wearing, Sheila Palmer, Benjamin Jackson, Kerrylyn Johnston, Lee Brown |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250079482
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| Zusammenfassung |
| Peatlands can be subject to wildfire or deliberate burning in many locations. Wildfires are
known to impact soil properties and runoff production in most soil types but relatively little
work has been conducted on peatlands. Furthermore in large parts of the UK uplands
prescribed vegetation burning on peat has taken place at regular intervals (e.g. every 8-25
years) on patches of around 300-900 sq. metres over the past century to support
increased grouse populations for sport shooting. However, there have been few studies
on how these prescribed fires influence near-surface hydrology. It is known that
macropores transport a large proportion of flow in near-surface peat layers and we
investigated their role in flow transport for fire sites using tension infiltrometers.
Measurements were performed, at replicated hillslope positions to control for slope position
effects, on unburnt peat (U) and where prescribed burning had taken place two years
(P2), four years (P4) and >15 years (P15+) prior to sampling. For the prescribed
burning plots, vegetation burning had also occurred at around a 15-20 year interval
for most of the past century. We also sampled a nearby wildfire site (W) with the
same sampling design where wildfire had occurred four months prior to sampling.
Both the contribution of macropore flow to overall infiltration, and the saturated
hydraulic conductivity, were significantly lower in the recently burnt sites (W, P2,
P4), compared to P15+ and U. There was no significant difference in macropore
flow contributions, effective macroporosity and saturated hydraulic conductivity
between P15+ and U. The results suggest fire influences the near-surface hydrological
functioning of peatlands but that ‘recovery’ for some hydrological processes to
prescribed vegetation burning may be possible within two decades if there are no further
fires. |
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