Table 1.
Diversity list for nematodes, bdelloid rotifers and tardigrades from East Antarctica showing previous record from the sampled regions.
Figure 1.
Maps showing the ten regions from East Antarctica (EA) where sampling was conducted (filled circles).
Abbreviations: Framnes Mountains (FM), Mawson Station (MS), Casey Station (CS), Sansom Island (SI), Larsemann-Islands (L-Isl), Stornes Peninsula (SP), Broknes Peninsula (BP), Hop Island (HI), Mather Peninsula (MP), and Vestfold Hills (VH). Other sectors and regions across Antarctica mentioned in the text (not included in this study): Dronning Maud Land (DML), Victoria Land (VL), and Ross Island (RI). Adapted from maps provided courtesy of the Australian Antarctic Division.
Table 2.
Geographic location and type of samples collected from ten regions across East Antarctica.
Figure 2.
Principal component analysis (PCA) on log [x+0.1] transformed and normalized values of abiotic data from 109 sites.
Symbol shapes represent region for each of the samples. Vectors labelled as region (Reg), elevation (elev), soil sample from moss bed (Cs_bed), fine sediment (FS), samples with moss filaments (moss), aspect, organic carbon (C), Olsen-phosphorus (P), NH4+, moisture in soil (Moist), electrical conductivity (EC), samples containing alga-cyanobacteria (al-cy), NO3−, and pH.
Figure 3.
(A) Hierarchical cluster of taxa composition based on Bray-Curtis similarity coefficient (presence/absence of microfaunal taxa).
(B) Microfauna total abundance given in grams of dry weight of soil (Tot ab/gdw); and elevation at which samples were collected. (C–E) values for soil geochemical variables for 109 samples across EA. Geochemical variables (units and acronyms): Olsen-phosphorus ‘P’ (mg/kg), NH4+ (ppm), NO3− (ppm), soil moisture ‘Moist’ (%), electric conductivity ‘EC’ (ds/m), and organic carbon ‘C’ (%). The Order of samples for graphs (B–E) is the same as indicated in cluster (A). Color-coded symbols identified by the Hierarchical cluster (separated by blue dotted line) represent microfaunal taxa categories (MT-cat): ‘0’ no microfauna, ‘1’ rot, ‘2’ rot-mit, ‘3’ rot-nem-mit, ‘4’ rot-tar-mit, ‘5’ rot-nem-tar-mit, ‘6’ rot-nem-cil-mit, , ‘7’ rot-nem-tar-cil-mit. ‘8’ rot-nem-cil, ‘9’ rot-nem-tar-cil, ‘10’ rot-cil, ‘11’ rot-tar-cil, ‘12’ rot-nem ‘13’ rot-tar, ‘14’ tar-nem ‘15’ rot-nem-tar, ‘16’ mit, ‘17’ nem-mit, ‘18’ nem-cil, and ‘19’ nem. Abbreviations used: rotifers (rot), tardigrades (tar), nematodes (nem), mites (mit), and ciliates (cil).
Figure 4.
(A) Hierarchical cluster of nematode composition based on Bray-Curtis similarity coefficient (presence/absence of morphologically identified taxa).
(B) Nematode total abundance given in grams of dry weight of soil (Nem/gdw); and elevation at which samples were collected. (C–E) values for soil geochemical variables for 109 samples across EA. Geochemical variables (units and acronyms): Olsen-phosphorus ‘P’ (mg/kg), NH4+ (ppm), NO3− (ppm), soil moisture ‘Moist’ (%), electric conductivity ‘EC’ (ds/m), and organic carbon ‘C’ (%). The Order of samples for graphs (B–E) is the same as indicated in cluster (A). Color-coded symbols identified by the Hierarchical cluster (separated by blue dotted line) represent nematode categories (Nem-cat): ‘0’ no nematodes, ‘1’ undetermined, ‘2’ Ha-Sc, ‘3’ Ha, ‘4’ Sc, ‘5’ Sc-Eu, ‘6’ Sc-Pt, ‘7’ Pt-Eu-Sc, ‘8’ Pa, ‘9’ Pt-Pa, ‘10’ Pt, and ‘11’ Eu-Pt. Abbreviations used: Plectus (Pt), Halomonhystera (Ha), cf. Panagrolaimidae (Pa), Scottnema (Sc), and Eudorylaimus (Eu).
Figure 5.
(A) Hierarchical cluster of rotifer composition based on Bray-Curtis similarity coefficient (presence/absence of morphologically identified taxa).
(B) Rotifer total abundance given in grams of dry weight of soil (Rot/gdw); and elevation at which samples were collected. (C–E) values for soil geochemical variables for 109 samples across EA. Geochemical variables (units and acronyms): Olsen-phosphorus ‘P’ (mg/kg), NH4+ (ppm), NO3− (ppm), soil moisture ‘Moist’ (%), electric conductivity ‘EC’ (ds/m), and organic carbon ‘C’ (%). The Order of samples for graphs (B–E) is the same as indicated in cluster (A). Color-coded symbols identified by the Hierarchical cluster (separated by blue dotted line) represent rotifer categories (Rot-cat): ‘0’ no rotifers, ‘1’ Ph, ‘2’ Ph-ub, ‘3’ Ph-Ad, ‘4’ Ph-Ad-ub, ‘5’ Ad, ‘6’ Ad-ub, ‘7’ ub-Monogonota, and ‘8’ ub. Abbreviations used: Adineta (Ad), Philodina (Ph), and unidentified bdelloid (ub).
Figure 6.
(A) Hierarchical cluster of tardigrade composition based on Bray-Curtis similarity coefficient (presence/absence of morphologically identified taxa).
(B) Tardigrade total abundance given in grams of dry weight of soil (Tar/gdw); and elevation at which samples were collected. (C–E) values for soil geochemical variables for 109 samples across EA. Geochemical variables (units and acronyms): Olsen-phosphorus ‘P’ (mg/kg), NH4+ (ppm), NO3− (ppm), soil moisture ‘Moist’ (%), electric conductivity ‘EC’ (ds/m), and organic carbon ‘C’ (%). The Order of samples for graphs (B–E) is the same as indicated in cluster (A). Color-coded symbols identified by the Hierarchical cluster (separated by blue dotted line) represent tardigrade categories (Tard-cat): ‘0’ no tardigrades, ‘1’ Parachela, ‘2’ Echiniscoidea, ‘3’ Parachela-Apochela-Echiniscoidea, and ‘4’ Parachela-Echiniscoidea.
Table 3.
Sample size (a), Taxa absent (b), Abundance (c), Percentage of Abundance (d), and taxa composition percentage (e) of microfauna from 109 soil samples at ten regions.
Table 4.
Result from Bioenv analysis showing the strongest correlations for abiotic variables (when considered individually or in connection to others) that best match the biotic matrices for microfauna total abundance and composition.
Table 5.
Result from Bioenv analysis showing the strongest correlations for abiotic variables (when considered individually or in connection to others) that best match the biotic matrices for nematode composition (all taxa combined, Plectus, Eudorylaimus and Scottnema), and abundance.
Table 6.
Result from Bioenv analysis showing the strongest correlations for abiotic variables (when considered individually or in connection to others) that best match the biotic matrices for rotifer composition (all taxa combined, Adineta and Philodina), and abundance.
Table 7.
Result from Bioenv analysis showing the strongest correlations for abiotic variables (when considered individually or in connection to others) that best match the biotic matrices for tardigrade composition and abundance.
Table 8.
Result from Bioenv analysis showing the strongest correlations for abiotic variables (when considered individually or in connection to others) that best match the biotic matrices for ciliate presence/absence and abundance.
Table 9.
Result from Bioenv analysis showing the strongest correlations for abiotic variables (when considered individually or in connection to others) that best match the biotic matrices for mite presence/absence and abundance.