TY - JOUR
T1 - Impact of declining atmospheric deposition on forest soil solution chemistry in Flanders, Belgium
AU - Verstraeten, Arne
AU - Neirynck, Johan
AU - Genouw, Gerrit
AU - Cools, Nathalie
AU - Roskams, Peter
AU - Hens, Maarten
N1 - Publication Authorstring : Verstraeten, A.; Neirynck, J.; Genouw, G.; Cools, N.; Roskams, P.; Hens, M.
Publication RefStringPartII : <i>Atmospheric Environment (1994) 62</i>: 50-63. <a href="http://dx.doi.org/10.1016/j.atmosenv.2012.08.017" target="_blank">dx.doi.org/10.1016/j.atmosenv.2012.08.017</a>
PY - 2012
Y1 - 2012
N2 - Throughout Europe and the USA, forest ecosystem functioning has been impacted by long-term excessive
deposition of acidifying compounds. In this study, we report on trends in stand deposition and soil
solution fluxes of inorganic nitrogen (N) and sulphur (S) compounds over a 17-year period (1994e2010)
in five ICP Forests monitoring plots in Flanders, northern Belgium. Deposition was dominated by N, and
primarily NH4
þ. Deposition of SO4 2 and NH4
þ declined by 56e68% and 40e59% respectively. Deposition of
NO
3 decreased by 17e30% in deciduous forest plots, but remained stable in coniferous forest plots. The
decrease of N and S deposition was parallelled by a simultaneous decline in base cation
(BC ¼ Ca2þ þ Kþ þ Mg2þ) deposition, resulting in a 45e74% decrease of potentially acidifying deposition.
Trends in soil solution fluxes of NH4
þ, NO3
, SO4 2 and BC mirrored declining depositions. Nitrate losses
below the rooting zone were eminent in both coniferous forest plots and in one deciduous forest plot,
while net SO4 2 release was observed in two deciduous forest plots. Critical limits for BC/Al ratio were
exceeded at the three plots on sandy soils with lower cation exchange capacity and base saturation. Soil
solution acid neutralizing capacity increased but remained negative, indicating that soil acidification
continued, as the start of recovery was delayed by a simultaneous decrease of BC depositions and shortterm
soil buffering processes. Despite substantial reductions, current N deposition levels still exceed 4e8
times the critical load for safeguarding sensitive lichen species, and are still 22e69% above the critical
load for maintaining ground vegetation diversity.
AB - Throughout Europe and the USA, forest ecosystem functioning has been impacted by long-term excessive
deposition of acidifying compounds. In this study, we report on trends in stand deposition and soil
solution fluxes of inorganic nitrogen (N) and sulphur (S) compounds over a 17-year period (1994e2010)
in five ICP Forests monitoring plots in Flanders, northern Belgium. Deposition was dominated by N, and
primarily NH4
þ. Deposition of SO4 2 and NH4
þ declined by 56e68% and 40e59% respectively. Deposition of
NO
3 decreased by 17e30% in deciduous forest plots, but remained stable in coniferous forest plots. The
decrease of N and S deposition was parallelled by a simultaneous decline in base cation
(BC ¼ Ca2þ þ Kþ þ Mg2þ) deposition, resulting in a 45e74% decrease of potentially acidifying deposition.
Trends in soil solution fluxes of NH4
þ, NO3
, SO4 2 and BC mirrored declining depositions. Nitrate losses
below the rooting zone were eminent in both coniferous forest plots and in one deciduous forest plot,
while net SO4 2 release was observed in two deciduous forest plots. Critical limits for BC/Al ratio were
exceeded at the three plots on sandy soils with lower cation exchange capacity and base saturation. Soil
solution acid neutralizing capacity increased but remained negative, indicating that soil acidification
continued, as the start of recovery was delayed by a simultaneous decrease of BC depositions and shortterm
soil buffering processes. Despite substantial reductions, current N deposition levels still exceed 4e8
times the critical load for safeguarding sensitive lichen species, and are still 22e69% above the critical
load for maintaining ground vegetation diversity.
U2 - 10.1016/j.atmosenv.2012.08.017
DO - 10.1016/j.atmosenv.2012.08.017
M3 - A1: Web of Science-article
VL - 62
SP - 50
EP - 63
JO - Atmospheric Environment
JF - Atmospheric Environment
ER -