Methodology:

Monthly sampling was carried out for seven species of soil arthropods (four species of Acari, two Collembola, 1 Diptera) over the year. Four species of Acari and three species of Collembola were collected at Bernsten Point, Elephant Flats and Gourlay Peninsula. The eighth species, Diptera, was collected at the base of Factory Bluffs. The invertebrates were collected by hand from the surfaces of rocks embedded in soil or vegetation.

Samples were kept at ambient temperature during transport to the laboratory located at the base on Signy Island. Adults of three larger and more robust mite species were then separated (A. antarcticus, H. belgicae, G. racovitzai), while the smaller S. villosus and the three springtails were not identified to life stage. Only larvae of the chironomidmidge were collected.

Over the study period both a Cahn gram electrobalance and a Sartorius electrobalance were used, the former sensitive to approximately 1 ng, the latter to 0.2 ng. Fresh and dry mass were obtained (dry mass obtained after drying at 60 degrees Celsius).

For the first four years of the study, animals of each species were weighed together (usually 5 replicates). During the following seven years, animals were weighed individually in small aluminium containers. A minimum of 20 animals of each species were weighed monthly.

Water content is expressed in the following two ways in the dataset:

1. Water content as a fresh weight percentage (column water_content_fresh_weight_perc) calculated as:

water_content_fresh_weight_perc = 100*(fresh_weight_sample_ug - dry_weight_sample_ug)/fresh_weight_sample_ug

2. Dry weight as (column water_content_dry_weight_ug):

water_content_dry_weight_g_g-1 = (fresh_weight_sample_ug - dry_weight_sample_ug)/dry_weight_sample_ug

Data quality:

For the first four years of data collection, limitations on balance equipment meant animals of each species (usually 5 replicates) were weighed together.

A small number of monthly samples were not collected as a result of adverse weather conditions.

For the periods January 1988 - April 1989 and July - December 1992, no data were obtained due to balance equipment failure.

Data flagged during collection and/or analysis as non-normal are denoted with a 'Y' in the column 'data_flag'.