Sampling at Qassiarsuk 2009

Objectives

• Collection of 40 microarthropod samples with soil corer from one location in 5 grazed
  and 5 ungrazed plots (4 samples per plot).
  
• Place 100 litterbags, 10 in each plot, to determine decomposition of cellulose filter paper after one year
  of field incubation.
  
• Collecting 16 30x20 cm blocks of soil/foerne to a depth of approx. 10 cm for bulk microarthropod extraction.
  
• Collection of soil samples for physico-chemical soil characterisation.
  

Sampling location

The location of the soil ecology sampling area is at the " Ruin 200", see Google maps, as defined by Jon Feilberg in 1985. It is situated 2-3 km south-west of Qassiarsuk at the inner west branch of the Tunnulliarfik fjord. It is a dwarf shrub heath (fjeldhede) (revling, Vaccinium uliginosum (mosebølle), Salix glauca (blågrå pil, spp. callicarpaea and var. glauca) while sheep grazing has partly transformed it into grassland slopes (DK: græsli).

Selection and positioning of sampling plots

The plot size for soil ecological investigation is 10x10 meter. For each grazed plot an ungrazed matching plot is identified as close as possible to each other, while still ensuring that the grazing factor is present/absent from the matching pair. One of the 5 pairs of grazed/ungrazed plots must be Jon Feilbergs original 15 m x 15 m pair of plots at the Ruin 200 location. Apart from the grazing factor the matching plots must have originally (in 1985) identical botanical composition and soil properties and this is fulfilled for the botanical plot numbers 322 and 324. In other words: Based on the former botanical characterisation of the study area before establishment of the grazing exclosure done by Jon Feilberg, it must be ensured that the vegetation was originally identical in the matching plots (grazed/ungrazed). Thus, the 4 pairs of plots will expectedly be positioned along the fence and with some distance into the area.

Microarthropod samples

16 big 20x30 cm blocks for bulk extraction are carefully cut and dug out of the soil
and kept in plastic boxes. 3 blocks from each plot and no. 16 from any of the plots.

Important: Avoid compression in any
stage of handling soil samples for microarthropods. The samples
should be stored at 5 ^oC.

4 samples are collected randomly from each plot using the split corer soil sampler.

Litterbags

VWR filter paper is used as a surrogate for indigenous litter and filled into litterbags. 100 litterbags each containing 2.0 g filter paper,
corresponding to 4 round pieces 9 cm Ø, are buried horizontally 3-5 cm into the soil. The litterbags are left open unless it is
envisaged that this will have unwanted consequences.
White marker sticks (from DMU) is used to ease finding the litter after 1 year.

The 10 litterbags are placed as indicated by the '*' in the grid:

Collection of soil samples for physico-chemical soil characterisation

Sample treatment at Naturinstituttet

After 1 year litterbags are retrieved and brought to the laboratory, and then cleaned
for roots, organic matter, soil particles etc. dried at 60 degrees and weighed.
If the remaining dried filter paper is still contaminated by soil particles, they will have
to be burned and loss on ignition (LOI) is used to determine the breakdown rate.

See detailed filter paper decomposition procedure.

Sample treatment at DMU/Silkeborg

• Extraction of microarthropods from standard 5.5 cm depth x 6 cm diameter soil cores, 40 pcs.
  
• Bulk extraction of large 20x30 cm soil/foerne blocks of microarthropods for natural isotope analysis, 16 pcs.
  
• Stable isotope analyses according to Analysis of trophic structure.
  
• Determination of
  
• • actual water content by drying a subsample of minimum 3 samples at 105 ^oC,
    
  • nutrients (minimum NPK)
  • soil texture incl. pH and organic matter
    of representative soil samples from upper 20 cm of the soil profile (concerning samples see above).
    
• A number of representative pieces of the filter paper batch are heated at 50 ^oC to determine water content
  and dry-weight and ignited in a muffle oven to determine organic matter and
  ash content.
  
  

  VWR cat. no. 516-0814; Qualitative filterpaper, 413; medium filtrationrate; particle retention 5-13 ym; size: 90 mm

Shipment list

Jon Feilberg will bring a cardboard box containing the following items:

• 40 cylinders for soil cores and 80 red lids
• 16 boxes for large 20x30 samples
• 10 zipper plastic bags each with 10 litterbags with filterpaper, ready to dig into the soil 
• 100 white pins for marking the placement of a litterbags
• 1 plastic box with handles, 28x38x17 (depth), can be used to return samples or whatever appropriate
  
• Filter paper for the Akia decomposition study 5 boxes >200 g.
  
• Some 200 empty litterbags for decomposition studies at Akia etc.
  

Contacts

Jon Feilberg/Biomedia
Kastrupvej 8
4100 Ringsted
Tlf.  57 60 01 25; Mob. 40 15 05 98

Katrine Raundrup, Naturinstituttet: +299 36 12 28; +299 27 03 06

Paul Henning Krogh

Department of Terrestrial Ecology
University of Aarhus
P.O. Box 314, Vejlsoevej 25
DK-8600 Silkeborg, Denmark
Office +45 89 20 15 88
Switchboard +45 89 20 14 00
Mobile +45 27 57 10 34
Fax +45 89 20 14 13
Private +45 32 11 71 06
E-mail krogh.ph@gmail.com

Speditør

DSV (aftale med Hilda Norberg) - Tlf. +4579297000