Post on 28-Feb-2019
TRENDS IN SOIL WATER COMPOSITION AT A HEAVILY POLLUTED SITE
EFFECTS OF DECREASED S-DEPOSITION AND VARIATIONS IN PRECIPITATION
R.D. VOGT1*, H.M. SEIP1, H. OREFELLEN1, G. SKOTTE1, C. IRGENS1, and J. TYSZKA2
1 University of Oslo, Dept. of Chemistry, P.O.Box 1033 Blindern, N-0315 Oslo,
Norway
2 Forest Research Institute,ul. Bitwy Warszawskiej 1920r Nr. 3, PL-00-
973 Warszawa, Poland
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Outline
Issue The influence of amount of precipitation on recovery response
The study siteDeposition trends
FindingsConclusions
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Influence of precipitation
The main result from a 5 years field acid addition experiment was that the Precipitation amount had a profound influence on the soil water chemistry
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Key issue
In many of the areas where there is an amelioration of the surface water chemistry following a decline i S-deposition there has also been an increase in the amount of precipitation
To what extent may increase in ANC in regions with declining S-deposition be related to variations in precipitation?
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The study site
Czerniawka in theKarkonoski National park in Poland
Coniferous
Deciduous
Mixed
Deteriorated stands
Urban area
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Decreasing large S-deposition
5.4g S m-2yr-1
between 1985 - 1996Decreased >50% since 1987No large local sources
Precipitation pH=4.3Throughfall KL =1.7
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Deposition trends
S-deposition in in the region was more than halved between 1987 and -96Rather small variations in S-deposition at the site during the studyThe annual amount of precipitation varied with almost 100%
Study period
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Soil chemistry
The %BS in the soil is very low
0
20
40
60
80
100
%
O B1 B2
Soil horizon
AlSHSBS
Horizon pHBaCl2 CECE
O 2.8 233B1 4.1 25B2 4.1 24
meq kg-1
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Soil water
Low pH values in O-horizons (average pH = 3.7)Mainly Al release buffer the pH in the mineral soilAl equivalents account for more than half of the total charge in the mineral soil solutionRCL={Al3+}/{Me2+} between 0.8 and 2 in the mineral soil
0
100
200
300
400
500
600
O A B1 B2 BCHorizons
ueq
L-1
0
100
200
300
400
500
600
ueq
L-1
H+ Al ekv Ca2+Mg2+ Na+ K+SO4 2- NO3 - Cl-
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Influence of wetness
01234
0100200
CL
mm
92Sp92S
92F93Sp
93S93F
94Sp94S
94F95Sp
95S95F
96Sp96S
96F
-1000-800-600-400-200
0200
0
100200
ANC
mm
92Sp92S
92F93Sp
93S93F
94Sp94S
94F95Sp
95S95F
96Sp96S
96F
Particularly wet conditions give especially favourable water quality
The soilwater quality was better in fall of 1996 than in 1993 albeit similar conditions
R
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A multivariate approach
PC1Recovery & dilution⌧Wetness and Time are highly
correlated• SO4 and Cl cluster• All chemical parameters are
negatively correlated to Wetness and Time along the PC1
PC2 Spatial variation within each soil horizon
-6 -4 -2 0 2 4 6-4
-2
0
2
4
6
8
0Plott
H
I
HH
B
D
F BB
HI
J
F
I
B
DE E
H
B
FE
I
F
G
E
G I
E
G
D
G
G
E
J
H
D
B
I
FD B
G
F
E
F
F
J
D
G
E
FE
G
G
H
I
E
I H
E
B
J
D
H+
TOC
AloCa
Mg Na
K
SO4
NO3Cl
F-tot
Al-eq
Time
Wetness
Recovery & Dilution (PC1)Sp
atia
l var
iatio
n (P
C2)
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Conclusions
Indications of improved soil-water quality at a heavily S-loaded site in west Poland from 1992 - 1996
However, this is probably to a large extent due to more precipitation during the last part of the period
This should be borne in mind in studies of recovery especially if only two or a few points in time are compared