Deakin University
Browse

File(s) under permanent embargo

Bacteria in tropical floodplain soils are sensitive to changes in saltwater

journal contribution
posted on 2018-01-01, 00:00 authored by Tiffanie Nelson, C Streten, K S Gibb, A A Chariton
Bacterial communities in floodplain and wetland soils cycle elements essential for flora and fauna. The
coastal habitats of northern Australia are threatened with increasing saltwater intrusion (SWI) events that will destroy
freshwater habitats. The effect of the impending SWI on bacterial communities is unknown. Here, we examined the
bacterial communities of a tropical river floodplain located in World Heritage Kakadu National Park. Using 16S rRNA
gene pyrosequencing, we measured the baseline bacterial communities from three morphologically distinct regions of the
floodplain (lower, upper and backwater swamp), within three zones of the South Alligator River (upstream, cuspate and
estuarine funnel or sinuous). Significant differences in the bacterial community were observed at each category of
floodplain morphology and river zone. The greatest differences were due to pH and salinity. Large changes in bacterial
compositions are predicted to occur with increases in salinity and pH. Saltwater intrusion is predicted to increase
substantially in the next decades with sea-level rise, and is likely to cause large and significant changes to the bacterial
community with unknown consequences for biogeochemical cycling. Kakadu National Park may benefit from
incorporating bacteria into routine studies, because we have shown here that they are sensitive indicators of change,
even across small ranges of abiotic variables.

History

Journal

Marine and freshwater research

Volume

69

Issue

7

Pagination

1110 - 1123

Publisher

CSIRO Publishing

Location

Clayton, Vic.

ISSN

1323-1650

Language

eng

Publication classification

C Journal article; C1 Refereed article in a scholarly journal

Copyright notice

2018, CSIRO