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| Titel |
Aluminum availability in forest floor of two acidified mountain watersheds |
| VerfasserIn |
Jiri Kana, Karolina Tahovská |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250040821
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| Zusammenfassung |
| We measured seasonal variability of soil chemistry in upper organic soil horizons (O
and A) in watersheds of two acidified mountain lakes, Plešné (PL) and Äertovo
(CT) in Bohemian Forest (Czech Republic). Both the localities are acidified, PL
watershed recently undergoes strong changes due to bark beetle infestation followed
by forest dieback. Soils were sampled in 6-week period during the years 2008 –
2009. The aim of the study was to investigate changes in Al availability in upper
organic soil horizons during year together with changes in nutrient availability and
transformations.
We observed significant seasonal variability in concentration of water extractable Al
(AlH2O) and exchangeable Al (AlEX, determined as 1M KCl extractable). Concentrations of
AlH2O, which represents quickly releasable form of Al, varied between 0.5 – 2.7 mg
kg-1and 0.5 – 4.4 mg kg-1in the PL - O and PL - A horizons, respectively, and between 0.4
– 1.4 and 0.6 – 3.5 mg kg-1in the CT - O and CT - A horizons, respectively. Concentrations
of AlH2O in PL watershed compared to AlH2O concentrations in CT watershed were higher,
despite higher soil pH values there. The main peaks of AlH2O concentrations were observed
during the winters, while the concentrations were lowest during the springs and the falls. The
major part (>90%) of AlH2O was the organically bound Al. Concentrations of
AlEX, representing potentially toxic Al form, were approximately 2 – 3 orders of
magnitude higher compared to AlH2O concentrations, and were consistently lower in PL
watershed.
In H2O extracts, we observed dramatic increase of available P concentrations in upper
organic horizons in PL watershed after elevated litter fall associated with forest dieback. In
parallel we also observed changes in nitrogen chemistry, especially significant increase of
NH4-N concentrations in both the horizons. Both the changes in P and N availability in the
PL watershed are probably connected with the forest dieback. (For more details on
nitrogen transformations in these soils see also Tahovská et al.: Nitrogen availability in
mountain spruce forest floor after defoliation induced by bark beetle infestation) |
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