WORKING GROUP 5

Soil sampling strategy and analysis on reference European volcanic soils


PROFILE N8 - IS

   

  • Date of description: 27-08-1999
  • Authors: A.G. Jongmans and F. van Oort, O. Arnalds
  • Location: Central North Iceland, Audkuluheidi
  • Altitude
  • GPS coordinates: x 5551000,
                                   y 7251900
  • Classification

 

 

Soil Climate; Cryic temperature regime, Udic moisture regime. Mean annual rainfall 800mm; mean annual temperature 1.0C, mild winter, frost 6-9 months in soil; snow cover 3-7 months

 
  Topography: Gently rolling  
  Landform: Upland glacial plain  
  Land element: Slope  

Position: Bottom  
  Slope: Nearly level  
Micro topography : Hummocky area, hummocs 10-30 cm high and 0.5-2 m2 in size, but considerable variation in shape and sizes.  
  Landuse/Vegetation: Communal grazing land for sheep; 80% vegetation cover. Heath with about 50% Rachomitrium moss, with Betula nana, Empetrum, Vaccinium heath and kobresia sp.; vegetation strongly influenced by land use.  
    Human influences:   
  Parent material: Glacial moraine under 50-100cm thick aeolian and volcanic ash  
  Effective soil depth: Moderately deep  
   Erosion: Water and wind erosion, dominantly active in historical times.  
  Drainage class: Well drained.    
  Internal drainage: Frost cracks on surface, rarely saturated; moderately hydraulic conductivity    

 

External drainage: Slow run-off  

 

Moisture conditions: Moist  

N8 - IS SOIL HORIZON DESCRIPTION:

O: 3-0 cm; partially decomposed organic materials; abrupt and smooth to:

A1: 0-8/16 cm; 7.5 YR 3/3; sandy loam; moderate fine to medium platy ; friable; many fine to medium roots; from 12-16 cm irregular bright spots, 1 cm, 10YR 4/5; abrupt and wavy to:

A2: 8/16-19/24 cm 5YR 3/3; sandy loam; no macro structure; very friable; no pores detectable; common fine roots; abrupt and tonguing to:

Bw1: 19/24-23/31 cm; 7.5YR 4/4; sandy loam; no macro structure; very friable; few fine pores; common fine roots; abrupt and tonguing to:

2Bw: 23/31-34/39 cm: 10YR 5/5; bright discontinuous tephra layer, slightly weathered; sandy loam; moderate fine platy structure; friable; common fine roots; occurrence of cryoturbation features, presence of material from the over- and under-laying horizons; abrupt and wavy to:

3Bw/4C: 34/39-56/59 cm; Bw 7.5YR 3/5; 30% 4C, glacial till material, 10YR 4/4; loam; few fine gravel, sub rounded, up to 3cm, slightly weathered; no macro structure; friable; few, fine roots; abrupt and smooth to:

4C: >56/59 cm; glacial till; 10YR 4/4; sandy clay loam; fine gravel to boulders, sub rounded, partly weathered; layers of 2 cm consisting of 3Bw material, distributed inclined to the soil surface as a result of cryoturbation; no macro structure; friable; few fine roots in the upper 10 cm.

 

PROFILE N9 - IS

 

  • Date of description: 28-08-1999
  •    Authors: A.G. Jongmans and F. van Oort, O. Arnalds
  • Location: South Iceland, Hella, 600m NE of the farm Ytri-Tunga, 30m from the north-end of a2 yrs old ditch, depth about 2.5m.
  • Altitude:  
  • GPS coordinates: x 529400,
    y 7082600

 

  • Classification

Soil Climate; Cryic/ Frigid temperature regime; Udic moisture regime; annual rainfall: 1150 mm, mean annual temperature 4.50 C, mild winters but cool summers, 4-5 month growing season; became wetland with two drier and warmer periods when Birch forest dominated
Landform: Flat, with low gently sloping hills in between
Land element: Glacial plain, South Lowlands
Position: Middle slope
Micro topography : Hummocky level area
Landuse/Vegetation: Moderately grazed by horses; grass cover > 90%; Festuca rubra, Poa pratensis, and Descamptia
Human influences: Very noticable environmental change about the Settlement 1125 yrs ago, increased aeolian deposition resulted in higher mineral content in the sediments and lighter soil colours; Profile is situated in a 2 yrs old ditch, 2.5 m deep
Parent material: 2.5-3m thick aeolian, tephra and organic materials. Site is near Mt Hekla and much influenced by volcanic activity in Hekla and Katla.
Effective soil depth: Moderately deep
Erosion: None
Drainage class: Somewhat poorly drained.
Internal drainage: Saturated for long periods, moderately-slow hydraulic conductivity (?)
Moisture conditions: Moist

N9 - IS SOIL HORIZON DESCRIPTION:

A1: 0-60 cm; 5YR 3/3; loam; the horizon has a high organic matter content; locally pockets of angular, fine gravely and sandy material; disturbed stratification, the entire horizon shows features of cryoturbation; the under horizon limit is market by a basaltic ash layer of 5 cm, 2.5YR 2.5/0 with a loamy sand texture; friable; common fine to medium roots; clear and wavy to:

H1: 60-95 cm 7.5YR 3/3; stratified horizon consisting of plant remnants; friable; common fine and medium roots; occurrence of discontinuous fine bands of basaltic ash; clear and wavy to:

C: 95-100cm; 10YR 3/2, with light spots of sand grains, 10YR 6/4; no macro structure; friable; few fine roots; abrupt and wavy to:

2H; 100-230 cm; 5YR 2.5/1.5; stratified horizon consisting of organic material with aeolian mineral and basaltic pyroclastic (2.5YR 2/0) layers with a loamy sand texture and ranging in thickness from 1-10 cm; at 160 cm some mineral layers up to 2 cm consisting of lighter coloured ryolitic material; organic material and ash layers are friable; at 120 and 170 cm wood remnants of birch up to 20-30 cm in size.

Last modified 30 October 2003 by IAK