At each site 5-25 soil samples were taken for organism enumeration and moisture content analysis as follows:  Sampling bags were prepared with one sterile 'Whirlpak' bag and clean plastic scoop per sample.  The location of the sampling was recorded each year so that areas were not re-sampled.  Using the plastic scoop, soil was collected to a 10 cm depth.  Very large rocks (>20 mm diameter) were excluded from the sample.  The soil was shoveled into the 'Whirlpak' bag until three quarters full (about 1.5 kg soil).  The soil was mixed well in the bag, then the bag was closed tightly, expelling as much air as possible.  The soil samples were stored in a cooler for

transportation.  On return to the laboratory (within 8 hours of sampling), the soils were stored at +5 degrees C until further processing.  

 

In the laboratory, soil samples were handled in a laminar flow hood to prevent contamination.  The Whirlpak bags of soil were mixed thoroughly prior to opening. Approximately 200cm3 of soil was placed in a pre-weighed 800mL plastic beaker. Rocks greater than 3-4mm in diameter were removed from the sample.  A sub-sample of approximately 50g was removed and placed in a pre-weighed aluminum dish, and weighed on a balance accurate to 0.01g.  This sample was dried at 105 degrees C for 24 hours.  The sample was removed, placed in a desiccator to cool down, and re-weighed.  These data were used to calculate water content of the soil and to express data as numbers of soil organisms per unit dry weight of soil.