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| Titel |
Chronology of landscape evolution during the last centuries in the Campine area, Northern Belgium: integrating geomorphological, palaeobotanical, historical and pollution archives |
| VerfasserIn |
K. Beerten, N. Vandersmissen, K. Deforce, N. Vandenberghe |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250065631
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| Zusammenfassung |
| The reconstruction of past landscapes yields valuable information on the future evolution of
the earth surface environment. Such reconstructions heavily rely on age control in order to
link processes with specific landscape changes. The aim of this study is to integrate various
archives that contain crucial elements to understand the evolution of the landscape in the
Campine area during the last several 100 years. To this end, various profiles are investigated
that contain multiple lines of evidence from geomorphological, palaeobotanical,
historical and elemental archives. The profiles were cut in historical drift sands
overlying (truncated) podzol soils that developed in Weichselian cover sands. The
dune forming drift sands are the main landscape forming element on the studied
interfluve in the river Nete catchment (Northern Belgium), and are thought to have been
the result of deforestation while pine reforestation is held responsible for dune
stabilisation.
Methods used are geomorphological techniques including profile description and
optically stimulated luminescence (OSL) dating, together with other techniques including
palynology, analysis of historical maps and stable lead analysis.
OSL ages of samples taken from the drift sands indicate that aeolian processes were
active already before ~ 500 yrs BP until ~ 250 yrs BP. Temporary landscape stabilisation
phases are clearly documented within the drift sands and are estimated to not last longer than
several decades. Pollen analyses suggest that drift sand deposition was ongoing ~ 500 yrs BP
ago in a deforested landscape with dominant heather vegetation and came to an
end before pine reforestation of the site. Historical maps and archives pinpoint the
reforestation age of the site around ~ 150 yrs BP while isolated patches of forest
already existed from ~ 250 yrs BP onwards. Stable lead, known to have been a
major pollutant since ~ 150 yrs BP in NW Europe and certainly since ~ 100 yrs BP
at the site, shows elevated concentrations in the very few upper cm of the drift
sands.
The obtained data clearly show that the investigated archives converge to a single
solution, except for the end of the drift sand phase. In contrast to what is commonly assumed,
the studied archives suggest that the major sand drifting phase ended before large scale
reforestation of the area. Possibly climatic and/or land-use changes other than reforestation
are responsible for the final stabilisation of the landscape in this particular area of the
Campine region. |
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