PREDICTING RECOVERY IN ACIDIFIED FRESHWATERS BY THE YEAR 2010, AND BEYOND

Contract EVK1-1999-00087 - RECOVER:2010

Part of the 'Sustainable Management and Quality of Water'

Ecosystem Functioning

Directorate General Research

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THE REGIONS

RESULTS

Bavaria, Germany

The NE-Bavaria Mountains (Germany) are characterized by low mean annual temperatures (5-6.5°C) and high precipitation (950-1050 mm). The Lehstenbach catchment is typical of the area, with soil developed from deeply weathered granitic bedrock, which are very acid with pH(CaCl2) < 4 and have a low base saturation (< 10% in the upper soil). The reduction in sulphate deposition from the year 1985 to 1993 was 35%. In contrast to the significant decrease in sulphate deposition in the catchment, sulphate in runoff shows only a very slight decrease up to the year 1998. Due to soil texture, low pH values and the depth of the weathered substrata soils have high sulphate storage capacities. The huge amounts of sulphate stored in the soils of the catchment act as a buffer mechanism which delays reversibility of surface water acidification by decades (Alewell 1995; Alewell et al., 1997, Manderscheid et al., 1999a,b). The Lehstenbach catchment is typical for the mountainous regions of Germany. Delay of reversibility of soil and water acidification due to release of previously stored sulphate has been reported for the Solling, the Harz as well as the Ore mountains (Erkenberg, 1991; Meiwes et al., 1994, Malessa 1995, Alewell, 1995; Alewell, 1998; Alewell et al., 1997).

Reversibility of soil acidification in catchments of deeply weathered soils

Site description Lehstenbach catchment

 Location  Fichtelgebirge mountain range, NE-Bavaria, Germany; (50N, 11E)
 Altitude  700-877 m.a.s.l.
 Annual temperature  5 - 6.5 ºC
 Annual Precipitation  950-1050 mm
 Size  4.2 km²
 Stock  90 % spruce (Picea abies (L.) karst.)
 Bedrock  Deeply weathered granite, partly covered by solifluction layers
 Soils  Mosaic of cambisols to cambic podzols
 Texture  Loamy sand to loam
 Soil pH  pH(CaCl2)<4

Deposition with throughfall in kg S ha-1 yr-1

1998        SO42-   15.0
 NO3-  12.4
 NH4+  9.4
 H+  0.6

 


 SO42- Reduction  
1985-1992  35% 
1985-1998 69% 

Average sulphate contents and estimated sulphate storage in soils and the weathered substrata of the Lehstenbach watershed, Germany.

   Sulphate content (µmol g-1)    Sulphate storage (kg S ha-1)      
  H2O
Extractable
Na2HPO4
Extractable   
H2O
Extractable  
Na2HPO4
Extractable   
   Average SD  Average  SD  Average  SD  Average  SD 
 B-horizons
(<0.5 m depth)*
 1.19 0.93  2.28  2.33  250  186  474  483 
 Weathered substrata#
(0.5-10m depth)
 0.64 0.53  1.14  1.28  1600  1344  2800  2304 

* from Jungnickel (1996), # from Schweisser (1998)

n=53 for B-horizons, n=44 for weathered substrata, SD=standard deviation

To view data from the Lehstenbach catchment and photographs of forest dieback CLICK HERE

Results from Germany


For more information contact: Christine.Alewell@bitoek.uni-bayreuth.de


REGIONS
Upland Uk
Germany
Southern Norway
Italy
Czech Republic

REFERENCES