How the forest dieback accelerated the recovery of soils from acidification: A case study in Plesne lake catchment.

0560165 - BC 2023 RIV CZ eng A - Abstrakt
Kaňa, Jiří - Tahovská, K. - Šantrůčková, H. - Kopáček, Jiří … celkem 7 autorů
How the forest dieback accelerated the recovery of soils from acidification: A case study in Plesne lake catchment.
CONTEMPLATING EARTH: SOIL AND LANDSCAPE CONSIDERATIONS. Brno: Mendelova univerzita, 2020 - (Balková, M.; Kučera, A.; Samec, P.). (2020), s. 148-148. ISBN 978-80-7509-766-8
Grant CEP: GA ČR(CZ) GA19-16605S
Institucionální podpora: RVO:60077344
Klíčová slova: bark beetle * soil sorption complex * base cations * recovery from acidifcation
Obor OECD: Environmental sciences (social aspects to be 5.7)

Bark beetle outbreak leads to an extensive dieback of Norway spruce in a mountain forest in the catchment of Plešné Lake (Bohemian Forest, Czech Republic), affected by anthropogenic acidification due to long-distance atmospheric transport of the S and N compounds. As this area falls into a non-intervention zone of the national park, all dead biomass remained on the site. This disturbance caused significant changes in the amount of the exchangeable soil cations (H+, Na+, K+, NH4+, Mg2+, Ca2+, Al3+) on the soil sorption complex in the upper soil layer (O and A horizons). During nine years in the aftermath of the forest dieback, the concentrations of the base cations (BC) more than doubled from ~120 to ~280 μeq g-1. The increased content of BC together with NH4+ were replaced with Al3+ and H+ on the soil sorption complex and their respective concentrations dropped from 40–20 and 110–75 μeq g-1 in the O horizon and 70–50 and 160–110 μeq g-1 in the A horizon. Ca2+ was the major player in this replacement throughout the whole study while K+ and NH4+ were influential only during the first three years after the forest dieback. The increase in the BC concentrations and decrease in exchangeable acidity (Al3+ and H+) increased soil base saturation considerably, from 40–75% and 30–55% in the O and A horizons, respectively. The effect of input of BC and NH4+ from decomposing litter was forced by an absence of effective withdraw by the reduced forest vegetation. As a result, the recovery of the soils from anthropogenic acidification was temporarily accelerated. Alterations in the soil sorption complex were also well mirrored in the chemistry of the streams draining the affected catchment. The increased concentrations of BC in water were in concert with the elevated content of BC in the soils (leaching of surplus BC) while the ionic Al concentrations in the streams increased as a result of their displacement from the soil sorption complex. The transport of the cations from the catchment balanced the increased terrestrial export of nitrates, with further consequences for lake water chemistry.
Trvalý link: https://hdl.handle.net/11104/0333172