Relationships between molecular bacterial diversity and chemistry of groundwater in the Wairarapa Valley, New Zealand

Figures & data

Figure 1 Groundwater sites sampled in the Wairarapa Valley and the Riversdale area, New Zealand. These sites are grouped into bioclusters based on their bacterial diversity (see ‘Results’ section). Each site is represented with a relevant symbol in a specific colour and shape to match with the biocluster to which it belongs.

Figure 2 Summary of the total number of FAM (black) and HEX (grey) T-RFs over 200 RFU in each sample.

Figure 3 Frequency summary (i.e. the number of sites at which each T-RF was detected). A, FAM; B, HEX T-RF.

Figure 4 Summary of Shannon diversity index (H′) values for each sample using FAM (black) and HEX (grey) OTUs.

Figure 5 Dendrogram produced by hierarchical cluster analysis performed using Ward's linkage rule with FAM and HEX T-RFs standardised to the sum of all peaks in each profile and the Bray-Curtis similarity index. The five sites that were successfully tested in the previous study by van Bekkum et al. (2006) are labelled (*). Four sites: Trout Hatchery; Johnson; CDC South; and George indicated with boxes with black margin as they were clustered together in that study, in contrast to Seymour which was clustered separately and is indicated by a grey-margined box.

Figure 6 Box-and-whisker plot comparisons of concentrations across bioclusters defined at the 3-cluster threshold. A, Fe; B, Mn; C, NH₄-N; D, NO₂-N; E, NO₃-N; F, dissolved oxygen.

Table 1 Summary of the relative magnitudes of chemical parameters in each biocluster at 3-cluster threshold.

Chemical parameter	Biocluster 1A	Biocluster 1B	Biocluster 2
Na	Medium	Low	High
K	Medium	Low	High
Mg	Medium	Low	High
Ca	Medium	Low	High
Pb	Not clear	Not clear	Not clear
Zn	Not clear	Not clear	Not clear
B	Medium	Low	High
HCO3	Medium	Low	High
Cl	Medium	Low	High
SO4	High	High	Low
NO3–N	High	Medium	Low
NO2–N	Low	Low	High
NH4–N	Low	Low	High
PO4–P	Low	Low	High
Fe	Low	Low	High
Mn	Low	Low	High
Br	Low	Low	High
F	Medium	Low	High
SiO2	High	Low	High
TDS	Medium	Low	High
TOC	Not clear	Not clear	Not clear
Alkalinity	Medium	Low	High
Total hardness	Medium	Low	High
Total cations	Medium	Low	High
Total anions	Medium	Low	High
Free CO2	Not clear	Not clear	Not clear
DO	Medium	High	Low
TON	High	Medium	Low
EC	Medium	Low	High
pH	Low	Low	High

Figure 7 Percentage of samples in each biocluster defined at 3-cluster threshold. A, As a function of aquifer confinement; B, as a function of groundwater bore usage.

Figure 8 Summary of mean Shannon diversity index (H′) values for each biocluster using FAM and HEX T-RFs. Bars represent the mean Shannon index and the error bars represent one standard deviation.

Table 2 Summary of groundwater characteristics in each biocluster.

Biocluster	Groundwater characteristics
Biocluster 1A	Oxidised water with possibly high human impact, Moderate to high bacterial diversity, Moderate TDS, Low pH, Low to moderate [Na], [K], [Mg], [Ca], [Cl], [HCO3] and [F], High alkalinity, Highest [SO4]
Biocluster 1B	Oxidised water with possibly low human impacted, Highest bacterial diversity, Lowest TDS, Low pH, Lowest [Na], [K], [Mg], [Ca], [Cl], [HCO3] and [F], High alkalinity, majority unconfined aquifers, Moderate to high [SO4]
Biocluster 2	Reduced water, Lowest bacterial diversity, Highest TDS, High pH, Highest [Na], [K], [Mg], [Ca], [Cl], [HCO3] and [F], High alkalinity, majority confined aquifers, Lowest [SO4],

Figure 9 Hierarchical cluster analysis pattern for the five samples: Seymour; Trout Hatchery; Johnson; CDC South; and George revealed by van Bekkum et al. (2006). Black and grey-margined boxes were used to indicate the sites belonging to the two different clusters represented in Figure 5.

van Bekkum M, Sainsbury JP, Daughney CJ, Chambers GK 2006. Molecular analysis of bacterial communities in groundwaters from selected wells in the Hutt Valley and the Wairarapa, New Zealand. New Zealand Journal of Marine and Freshwater Research 40: 91–106. 10.1080/00288330.2006.9517405

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