Soil invertebrates of the Windmill Island region

Full description

Samples were collected from:

Clark Peninsula (ASPA 136)
Bailey Peninsula (ASPA 135)
Bailey Peninsula near Casey Station
Robinson's Ridge

Specific GPS coordinates are given in the download file.

Methods:
A total of 74 soil samples were collected across the four sampling areas listed above. At Robinsons Ridge and Bailey Peninsula (ASPA 135) samples were collected along one long transect (sample points numbered consecutively). At Bailey Peninsula near Casey Station and at Clark Peninsula samples were collected along each of three transects (identified as T1 to T3).

An additional 24 moss samples were collected as part of another ongoing project (AAS 4046) monitoring vegetation type changes at Robinson Ridge and Bailey Peninsula (ASPA 135). A = lichen dominated plots; M = moribund moss dominated plots; B = bryophyte dominated plots. Photos of the quadrats (taken in 2002/3, when the quadrats were established under AAS 1313), in which these samples were collected in the vicinity of, are available at: http://data.aad.gov.au/aadc/metadata/metadata.cfm?entry_id=ASAC_1313_ASPA135_Photos
(where sample codes are L = lichen, T = transition and B = bryophyte dominated communities, corresponding to codes A, M and B, respectively).

At each site for each soil sample we recorded the percentage of cover types (bare ground, rock, moss, lichen, visible algae) within a 25 x 25 cm area centred above the sampling point. Soil samples for soil properties and extraction of soil invertebrates were then collected from a depth of 0-10 cm using a clean plastic scoop. For moss samples, the cover and depth of moss was measured before a small sample of moss was collected with a pair of tweezers. Sub-samples of these moss samples were used for extraction of soil invertebrates and for calculating moisture content.

Nematodes, tardigrades and rotifers were extracted from ~50 g wet soil and 0.2-2 g wet moss depending on the size of sample available using a modified Baermann funnel technique. Extractions were kept at ambient laboratory temperature (approximately 20 degrees C) for 6 h before a 25W light bulb was turned on over the funnels, heating the water to 28-29 degrees C for another 42 h (i.e. a total of 48 h).
Abundances were converted to individuals (ind.) kg-1 dry soil and ind. g-1 dry moss for soil and moss samples, respectively.

Mites were extracted from ~15 g wet soil. The soil was poured into a 60 mL glass beaker containing a 40 mL sugar solution (1.33M; 454 g/L H2O). The mix was gently stirred with a spatula and left for 10 min. All individuals were subsequently picked from the surface of the solution under a dissection microscope and transferred into eppendorf tubes containing 70% ethanol. The stirring-collection procedure was repeated until no further individuals were recovered from each sample and densities were converted to ind. kg-1 dry soil.

Soil moisture was estimated gravimetrically by drying ~25 g wet soil at 105 degrees C for 48 h. Moss moisture levels were estimated by weighing the moss samples before extractions and again after drying the moss samples at 105 degrees C for 24 h after extractions had been undertaken. Soil pH was measured on a 2:1 DI water:soil solution and electrical conductivity was measured on a 5:1 DI water:soil solution using a TSP WP-81 pH and conductivity meter at Casey Station. The meter was calibrated using standard pH-buffer solutions and a conductivity standard (1413 plus or minus 14 micro S/cm at 25 degrees C). Soil carbon (C) and nitrogen (N) content was measured using a Leco TruMac CN Macro at the University of Western Sydney.

Data are stored in the file: AAS 4100 Windmill Islands_Soil invertebrate Distribution data.xlsx

Data available - soil samples:
Sample ID - includes name of site (Robinsons Ridge, Bailey Peninsula (ASPA 135), Bailey Peninsula near Casey Station and Clark Peninsula) and the sample number within these sites
Barcode - unique identifying code for soil samples (used for sample tracking)
GPS coordinates - location of sampling point in degrees and decimal minutes, South and East
soil moisture (%) - soil moisture content (%), estimated gravimetrically by drying ~25 g wet soil at 105 degrees C for 48 h
pH - pH value, measured on a 2:1 DI water:soil solution using a TSP WP-81 pH and conductivity meter at Casey Station
electrical conductivity (mS/cm) - electrical conductivity (mS/cm), measured on a 5:1 DI water:soil solution using a TSP WP-81 pH and conductivity meter at Casey Station
total soil carbon (%) - total soil carbon content (%), measured using a Leco TruMac CN Macro at the University of Western Sydney
total soil nitrogen (%) - total soil nitrogen content (%), measured using a Leco TruMac CN Macro at the University of Western Sydney
C:N ratio - C:N ratio, calculated as ratio of total soil carbon (%) to total soil nitrogen (%)
Moss - moss cover (%), over 25 x 25 cm area, centred above sampling point
Lichen - lichen cover (%), over 25 x 25 cm area, centred above sampling point
Bare ground - bare ground cover (%), over 25 x 25 cm area, centred above sampling point
Stones - stones greater than 2 mm cover (%), over 25 x 25 cm area, centred above sampling point
Algae - visible algae cover (%), over 25 x 25 cm area, centred above sampling point
Nematoda - abundance of nematodes extracted from sample per kg dry soil
Tardigrada - abundance of tardigrades extracted from sample per kg dry soil
Rotifera - abundance of rotifers extracted from sample per kg dry soil
Acari - abundance of mites extracted from sample per kg dry soil

Data available - moss samples:
Site - sample site name; Robinsons Ridge or APSA 135
Sample ID - sample plot code, where letters denote community type; A = Lichen, M = Moribund, B = Bryophyte. Note, these codes correspond to L = Lichen, T = Transition and B = bryophyte, respectively, in other in other work surveying vegetation in these permanently marked quadrats (AAS 1313, 4036 and SOE72). Photos of the quadrats (taken in 2002/3), in which samples were collected in the vicinity of, are available at: http://data.aad.gov.au/aadc/metadata/metadata.cfm?entry_id=ASAC_1313_ASPA135_Photos
Dominant vegetation type - Categories; Lichen, Moribund Moss and Bryophyte (as per community types described in 'Sample ID' for permanently marked quadrats)
moss moisture (% dry weight) - moisture content of moss (% dry weight), estimated by weighing the moss samples before extractions and again after drying the moss samples at 105 degrees C for 24 h after extractions had been undertaken
moss depth (cm) - depth of moss bed (cm) at point sample was collected
moss cover (%) - moss cover (%), over 25 x 25 cm area, centred above sampling point
Nematoda - abundance of nematodes extracted from sample per g dry moss
Tardigrada - abundance of tardigrades extracted from sample per g dry moss
Rotifera - abundance of rotifers extracted from sample per g dry moss

Lineage

Progress Code: completed

Statement: Two species of nematodes were identified in the samples collected (Plectus murrayi and P. frigophilus), but it was not possible to estimate species-specific abundances as the juveniles of the two species cannot be separated reliably morphologically. Hence, only total nematode abundance is included.